Archive for the ‘VMWare’ Category

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Quick-Take: Removable Media and Update Manager Host Remediation

January 31, 2013

Thanks to a spate of upgrades to vSphere 5.1, I recently (re)discovered the following inconvenient result when applying an update to a DRS cluster from Update Manager (5.1.0.13071, using vCenter Server Appliance 5.1.0 build 947673):

Remediate entity ‘vm11.solori.labs’  Host has VMs ‘View-PSG’ , vUM5 with connected removable media devices. This prevents putting the host into maintenance mode. Disconnect the removable devices and try again.

Immediately I thought: “Great! I left a host-only ISO connected to these VMs.” However, that assumption was as flawed as Update Manager’s assumption that the workloads cannot be vMotion’d without disconnecting the removable media. In fact, the removable media indicated was connected to a shared ISO repository available to all hosts in the cluster. However, I was to blame and not Update Manager, as I had not remembered that Update Manager’s default response to removable media is to abort the process. Since cluster remediation is a powerful feature made possible by Distributed Resource Scheduler (DRS) in Enterprise (and above) vSphere editions that may be new to the feature to many (especially uplifted “Advanced AK” users), it seemed like something worth reviewing and blogging about.

Why is this a big deal?

More the the point, why does this seem to run contrary to “a common sense” response?

First, the manual for remediation of a host in a DRS cluster would include:

  1. Applying “Maintenance Mode” to the host,
  2. Selecting the appropriate action for “powered-off and suspended” workloads, and
  3. Allowing DRS to choose placement and finally vMotion those workloads to an alternate host.

In the case of VMs with removable media attached, this set of actions will result in the workloads being vMotion’d (without warning or hesitation) so long as the other hosts in the cluster have access to the removable media source (i.e. shared storage, not “Host Device.”) However, in the case of Update Manger remediation, the following are documented road blocks to a successful remediation (without administrative override):

  1. A CD/DVD drive is attached (any method),
  2. A floppy drive is attached (any method),
  3. HA admission control prevents migration of the virtual machine,
  4. DPM is enabled on the cluster,
  5. EVC is disabled on the cluster,
  6. DRS is disabled on the cluster (preventing migration),
  7. Fault Tolerance (FT) is enabled for a VM on the host in the cluter.

Therefore it is “by design” that a scheduled remediation would have failed – even if the removable media would be eligible for vMotion. To assist in the evaluation of “obstacles to successful deferred remediation” a cluster remediation report is available (see below).

Generating a remediation report prior to scheduling a Update Manager remediation.

Generating a remediation report prior to scheduling a Update Manager remediation.

In fact, the report will list all possible road blocks to remediation whether or not matching overrides are selected (potentially misleading, certainly not useful for predicting the outcome of the remediation attempt). While this too is counter intuitive, it serves as a reminder of the show-stoppers to successful remediation. For the offending “removable media” override, the appropriate check-box can be found on the options page just prior to the remediation report:

Disabling removable media during Update Manager driven remediation.

Disabling removable media during Update Manager driven remediation.

The inclusion of this override allows Update Manager to slog through the remediation without respect to the attached status of removable media. Likewise, the other remediation overrides will enable successful completion of the remediation process; these overrides are:

  1. Maintenance Mode Settings:
    1. VM Power State prior to remediation:  Do not change, Power off, Suspend
    2. Temporarily disable any removable media devices;
    3. Retry maintenance mode in case of failure (delay and attempts);
  2. Cluster Settings:
    1. Temporarily Disable Distributed Power Management (forces “sleeping” hosts to power-on prior to next steps in remediation);
    2. Temporarily Disable High Availability Admission Control (allows for host remediation to violate host-resource reservation margins);
    3. Temporarily Disable Fault Tolerance (FT) (admonished  to remediate all cluster hosts in the same update cycle to maintain FT compatibility);
    4. Enable parallel remediation for hosts in cluster (will not violate DRS anti-affinity constraints);
      1. Automatically determine the maximum number of concurrently remediated hosts, or
      2. Limit the number of concurrent hosts (1-32);
    5. Migrate powered off and suspended virtual machines to other hosts in the cluster (helpful when a remediation leaves a host in an unserviceable condition);
  3.  PXE Booted ESXi Host Settings:
    1. Allow installation of additional software on PXE booted ESXi 5.x hosts (requires the use of an updated PXE boot image – Update Manager will NOT reboot the PXE booted ESXi host.)

These settings are available at the time of remediation scheduling and as host/cluster defaults (Update Manager Admin View.)

SOLORI’s Take: So while it follows that the remediation process is NOT as similar to the manual process as one might think, it still can be made to function accordingly (almost.) There IS a big difference between disabling removable media and making vMotion-aware decisions about hosts. Perhaps VMware could take a few cycles to determine whether or not a host is bound to a removable media device (either through Host Device or local storage resource) and make a more intelligent decision about removable media.

vSphere already has the ability to identify point-resource dependencies, it would be nice to see this information more intelligently correlated where cluster management is concerned. Currently, instead of “asking” DRS for a dependency list, it just seems to just ask the hosts “do you have removable media plugged-into any VM’s” – and if the answer is “yes” it stops right there… Still, not very intuitive for a feature (DRS) that’s been around since Virtual Infrastructure 3 and vCenter 2.

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Short-Take: vSphere vCloud Suite – Cheat Sheet

August 27, 2012

VMworld 2012 Announcements

VMware announces a new product package based on vCloud Director and vSphere Enterprise Plus called vCloud Suite. Existing users of vSphere Enterprise Plus (with valid SnS as of 8/27/2012) – including Academic and Federal users – may qualify for a “free” upgrade (actually $1/CPU) to “Standard” edition of vCloud Suite. Likewise, users with valid SnS and vSphere Enterprise (not Plus) qualify for a reduced cost upgrade to vCloud Suite Standard at $682/CPU.

Qualifying users have until December 15, 2012 to complete the transaction. Upgrades to other editions of vCloud Suite from Enterprise and Enterprise Plus are available as well – at additional cost per CPU.

vCloud Suite Cheat Sheet

Summary of new vCloud Suite offering and tiers (including links):

vCloud Suite
Standard Advanced Enterprise
Virtualization VMware vSphere Enterprise Plus Edition * * *
Cloud Infrastructure vCloud Director and vCloud Connector * * *
Standard vCloud Networking and Security * * *
Advanced vCloud Networking and Security * *
vCenter Site Recovery Manager Enterprise *
Operations Management vCenter Operations Management Suite vCOps Advanced vCOps Enterprise
VMware vCenter Chargeback Manager™ *
VMware vCenter Configuration Manager™ *
VMware vCenter Infrastructure Navigator™ *
vFabric Application Director *
Licensing Per CPU, Enterprise Plus basis $4,995.00 $7,495.00 $11,495.00
Support Basic: Per CPU, Per Year $1,049.00 $1,574.00 $2,414.00
Production: Per CPU, Per Year $1,249.00 $1,874.00 $2,874.00

Per-VM Pricing All But Gone

The introduction of vCloud Suite side-steps the vCloud Director per-VM licensing model and allows private cloud to scale based on the more predictable per-CPU infrastructure metric. Public cloud service providers will still be interested in per-VM foot prints and billing structures, but at least private cloud can be unshackled from the confines of per-VM vCD and vRAM issues; which segways nicely into the next tidbit…

In Other News…

VMware effectively kills vRAM by including “unlimited” vRAM entitlements in all editions of vSphere.

SMB’s may be pleased to note that VMware also now includes the vSphere Storate Appliance with all acceleration kits except vSphere Essentials at no additional cost (versus vSphere 5.0 kits). This is especially good for ROBO operations using Essentials Plus. The standalone cost for vSphere Storage Appliance is now $3,495.

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NFS and VMware: Perfect for Small Business? Part 1 – Introduction

August 22, 2012

Nexenta System’s “open storage” software made significant inroads into the VMware community over the last year with NFS storage. Even though Nexenta has been a partner with VMware for much longer, the storage vendor really made it’s debut at last year’s VMworld 2011 Hands-on-Labs by showcasing it’s NFS-for-VMware solution running on commodity hardware:

And, here’s the kicker, NexentaStor was running on industry standard hardware from Supermicro with STEC drives for write and read cache and 7200 rpm SAS drives for capacity.  Monday some DRAM on one of the four servers (two HA pairs) failed.  And no end users noticed because of our HA cluster performed correctly and failed over.  Meanwhile our load increased from a designed 33% to over 60% of the total load of the Hands on Lab due to unspecified issues with either NetApp or EMC.

Evan Powell, CEO – Nexenta Systems, VMworld Reviewed

While this was indeed an important inflection point in the VMware/Nexenta relationship, in broader terms Nexenta’s success at VMworld was the probably the moment when commodity NFS stepped out of the shadow of block storage. To be fair, there are many enterprise alternatives to Nexenta for NFS storage – like NetApp and EMC, but there are few can be deployed on commodity hardware, fewer that do both hardware and virtual storage appliances, and fewer still that have commercially licensed and community licensed distributions of the same platform.

If you’ve ever asked the question, “what’s the best storage solution for my vSphere stack?” I’d be willing to bet that NFS was not high on the list of recommendations. If you’ve looked at the related product marketing materials, as I have, or engaged front-line VMware personnel in a discussion of primary storage solutions, between 2009 and 2011, as I have, you’d be hard pressed to leave the conversation with a recommendation to use NFS. If Nexenta’s appearance can “prove” that open storage solutions based on NFS (and commodity hardware) are “ready” for big cloud infrastructures, can it be true that it’s a perfect fit for a small business’ private cloud? I’d say a resounding YES, but…

Introduction, NFS versus Block Storage

Before you say, “thanks for the tip, Collin, but who needs commercial stuff when NFS services are included in practically every Linux distribution, and “no cost” solutions -like FreeNAS – make NFS cheap and easy?” While it is true that solutions like this have been very popular with lab and bare-bones users, but most enterprises (even small ones) require a “bet the business” level of support and stability that isn’t often found in “community supported” distributions and do-it-yourself implementations. Even if the though “any NFSv3 server” – properly sized and configured – should work with VMware according to its abilities: it’s up to you to decide if the basket fits your eggs. The commercial NFS vendors really know their stuff, so you’re buying expertise, experience and a well-refined playbook: something you’ll be giving up when you go it alone.

Despite being “block storage’s whipping boy,” to say NFS is “not ready for prime time” in today’s VMware product matrix would be the height of FUD-peddling. On the contrary, a well know post in 2009 from noted EMC’r Chad Sakac and NetApp’s Vaughn Stewart made a great case for NFS in the enterprise in their multi-vendor post back in 2009. Since then, many improvements in NFS offerings and vSphere capabilities have increased NFS’ appeal in that space, not diminished it. To quote the Virtual Geek:

“NFS is an absolutely legitimate storage model for VMware – with many advantages.”

– Chad Sakac, aka Virtual Geek, EMC VP VMware Technology Alliance

Certainly there is a lot to like in pairing NFS with vSphere 5.x no matter the scale of the enterprise. Here are some of the high-points:

  • NFS works seamlessly with Storage I/O Control and Network I/O Control to support converged network architectures;
  • NFS exposes VMDKs to 3rd party tools and scripts without VMFS proxies, enabling:
    • Simple Backup/Recovery of VM, VMDK from NAS is a file copy operation
    • Linux, Windows7, etc. support NFS clients out of the box
    • Replication of VM or VMDK from NAS can be achieved simply with rsync
    • Use of snapshotted NFS volumes does not require ESX/VMFS
  • Reclamation of unused storage is not array dependent (file deletes return to storage immediately without SCSI Unmap support or equivalent)
  • Not subject to LUN locking and related performance issues in block/VMFS
  • It’s simpler to use: in the link above, VMware dedicates 24 pages to block/VMFS and only 3 to NFS
  • Presentation and management of NAS storage is very familiar (it’s a filer)
  • NFS is very forgiving of “imperfect” network configurations – compared to iSCSI, especially where network time-outs and latency are concerned
  • NFS storage does not need to be available at ESXi boot time, enabling VMs to exist on VSA running on-top of the host ESXi server (enabling recursive storage possibilities and reduced/shared hardware costs)
  • Mounting an NFS snapshot to vSphere does not include a signature operation (or risk possible collision)
  • NFS does not require VAAI to resolve SCSI file locking and VM loading limitations consistent with SCSI-based block storage
  • vSphere 5 currently support 256 NFS mounts per host
    • NFS.MaxVolumes (per host) – default 8, max 256
  • Single file size not limited on NFS file systems, however
    • Without 3rd party NAS VAAI, all VMDKs on NAS are always thin provisioned
    • Single file size limited to NAS vendor file system constraints
    • VMDK uses 512-byte sectors, so it suffers from the same limitations as physical disks, hence it will still have a 2TB-512-byte limit (since VMware has no 4K-byte sector VMDK, there will be no way to support 2TB+ VMDKs on NFS until that time)
  • NFS volumes are not limited in size
    • For NetApp WAFL, the limit is up to 100TB (with restrictions)
    • For NexentaStor, the limit is determined by the zpool size
  • On-line expansion of an NFS file system is a one-step operation: expand the file system on the filer

That said, NFS still cannot replace block storage on Tier 1 applications that were designed for block storage. Even iSCSI – arguably the least common denominator in shared block storage for VMware – still has some built-in advantages (and unique disadvantages) as compared to NFS. Likewise, when we’re talking about block storage in VMware we’re usually talking about VMFS too:

  • Writes are almost always asynchronous, making even low-end iSCSI “appear” to be faster than low-end NFS
  • Interface redundancy is straight forward and deterministic with many good options for redundancy
  • Storage latency in iSCSI/block is “more predictable” across common use cases
  • vSphere 5 currently supports 256 LUNs per host (similar to NFS mount limit)
    • Disk.MaxLUN (per target) – default 256, max 256
    • Total VMFS LUNs per host cannot exceed Disk.MaxLUN, regardless of type (FC, SAS, iSCSI, etc.)
  • vSphere VMFS3/5 limits single file size (VMDK and virtual RDM) to 2TB (minus 512 bytes)
  • VMFS3 limits single volume size to 50-64TB depending on block size chosen when formatted
  • VMFS5 limits single volume size to 64TB for VMFS5 (always uses 1MB block size)
  • vSphere’s storage telemetry is still geared towards block versus filer storage, making trouble-shooting of “performance issues” more available
  • Pairing storage to interface is much easier to do, even on-the-fly
  • Exchange 2010 expressly forbids the use of NAS storage as VMDK datastores
  • Virtual RDM and Clustering (shared block) require block storage (in some cases, not even iSCSI qualifies for support)
  • Tier 1 application support on block-based storage is generally better (familiarity and testing)
  • VMware VAAI for block storage ships with vSphere, similar acceleration features for NAS must come from the vendor (creating a much lest robust out-of-the-box experience for SMB)
  • On-line VMFS expansion usually requires two steps, with some caveats:
    • For VMFS expansions using a single LUN expansions under 2TB: (1) expand the underlying LUN on the SAN, (2) expand VMFS with the new space on the LUN
    • Single LUN expansions over 2TB require VMFS5
    • VMFS3 volume expansion beyond 2TB require multiple extents, each of which may not exceed 2TB-512B – loss of a single extent in a multi-extent volume could mean a loss of the entire volume
    • VMFS5 supports single LUNs (extents) as large as 60TB

Sparse VAAI issues aside, NFS is a great go-to storage protocol for most virtual workloads that do not strictly require block or shared-block storage back-ends (clustering, et al). Where NFS struggles today – in terms of VMware implementations in the SMB space – is in network resiliency. It is not that you cannot make NFS resilient to network failures, it’s more or less that redundancy is not neatly baked-into the service or protocol like it is for iSCSI, SAS and Fiber Channel – these block-based services have mature, multi-session amd multi-path capabilities at the service level (multi-path targets and initiators).

Note about 2TB VMDK limitations – given that most modern OSes running as supported virtual machines support some form of LUN concatenation (extents) to bypass 2TB physical disk limitations, the very same facilities can be leveraged to bypass the 2TB VMDK limits for these OSes. While this is not an optimal solution, it is a supported one. Today’s physical disks that exceed 2TB in size do so with 4KB sectors instead of 512B sectors. Currently, there is no 4KB sector VMDK analog.

Next Up, NFS and Path Redundancy

Hopefully by now there’s a compelling argument to look deeper into the NFS/VMware question, but – as with most shared, network storage – the rubber meets the road at the network layer. To me, the secret to making NFS more robust is in the network architecture that underpins it: depending on the complexity of the environment, the network layer will make or break an NFS implementation. In some ways there’s a lot more to making NFS “redundant’ (due to it’s lack of multipath capabilities): it’s not impossible; it’s not difficult; it’s just full of options and caveats.

Unlike block storage, you can’t “throw up two network interfaces, two target ports and two initiator ports” and easily have path redundancy and multipath data. With NFS, the network – not the storage service – does most of the “heavy lifting” and – as you’ll see in the next post – NFS has absolutely no concept of multipath. Therefore, I’m going to spend the next entry reviewing some of the main points driving network and NFS service dependencies that make understanding NFS network resiliency a bit more accessible.

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Quick-Take: vCenter Server 5.0 Update 1b, Appliance Replaced DB2 with Postgres

August 17, 2012

VMware announced the availability of vCenter Server 5.0 Update 1b today along with some really good news for the fans of openness:

vCenter Server Appliance Database Support: The DB2 express embedded database provided with the vCenter Server Appliance has been replaced with VMware vPostgres database. This decreases the appliance footprint and reduces the time to deploy vCenter Server further.

vCenter 5.0U1b Release Notes

Ironically and despite its reference in the release notes, the VMware Product Interoperability Matrix has yet to be updated to include 5.0U1b for reference, so  the official impact of an upgrade is as-yet unknown.

VMware Product Interoperability Matrix not updated at time of vCenter 5U1b release.

Also, couple of new test questions are going to be tricky moving forward as the support for Oracle has been expanded:

  • vCenter Server 5.0 Update 1b introduces support for the following vCenter Databases
    • Oracle 11g Enterprise Edition, Standard Edition, Standard ONE Edition Release 2 [11.2.0.3] – 64 bit
    • Oracle 11g Enterprise Edition, Standard Edition, Standard ONE Edition Release 2 [11.2.0.3] – 32 bit

Besides still not supporting IPv6 and continuing the limitation of 5 hosts and 50 VMs, there is some additional leg work needed to upgrade the vCenter Server Appliance 5.0U1a to U1b as specified in KB2017801:

  1. Create a new virtual disk with size 20GB and attach it to the vCenter Server Appliance.
  2. Log in to the vCenter Server Appliance’s console and format the new disk as follows:
    1. At the command line, type, “echo “- – -” > /sys/class/scsi_host/host0/scan”.
    2. Type, “parted -s /dev/sdc mklabel msdos”.
    3. Type, “parted -s /dev/sdc mkpartfs primary ext2 0 22G”.
  3. Mount the new partition under /storage/db/export:
    1. Type, “mkdir -p /storage/db/export”.
    2. Type, “mount /dev/sdc1 /storage/db/export”.
  4. Repeat the update process.
  5. You can remove the new disk after the update process finishes successfully and the vCenter Server Appliance is shut down.

SOLORI’s Take: Until the interop matrix is updated, it’s hard to know what you’re getting into with the update (Update: as you can see from Joshua Andrews’ post on SOS tech), but the inclusion of vPostgres – VMware’s vFabric deployment of PostgreSQL 9.1.x – makes taking a look at the “crippled” appliance version a bit more tantalizing.  Hopefully, the next release will “unshackle” the vCenter Appliance beyond the 5/50 limitations – certainly vPostgres is up to the task of managing many, many more hosts and VMs (vCD anyone?) Cheers, VMware!

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Quick-Take: How Virtual Backup Can Invite Disaster

August 1, 2012

There have always been things about virtualizing the enterprise that have concerned me. Most boil down to Uncle Ben’s admonishment to his nephew, Peter Parker, in Stan Lee’s Spider-Man, “with great power comes great responsibility.” Nothing could be more applicable to the state of modern virtualization today.

Back in “the day” when all this VMware stuff was scary and “complicated,” it carried enough “voodoo mystique” that (often defacto) VMware admins either knew everything there was to know about their infrastructure, or they just left it to the experts. Today, virtualization has reached such high levels of accessibility that I think even my 102 year old Nana could clone a live VM; now that is scary.

Enter Veeam Backup, et al

Case in point is Veeam Backup and Recovery 6 (VBR6). Once an infrastructure exceeds the limits of VMware Data Recovery (VDR), it just doesn’t get much easier to backup your cadre of virtual machines than VBR6. Unlike VDR, VBR6 has three modes of access to virtual machine disks:

  1. Direct SAN  Access – VBR6 backup server/proxy has direct access to the VMFS LUNs containing virtual machine disks – very fast, very low overhead;
  2. Virtual Appliance – VBR6 backup server/proxy, running as a virtual machine, leverages it’s relation to the ESXi host to access virtual machine disks using the ESXi host as a go-between – fast, moderate overhead;
  3. Network – VBR6 backup server/proxy accesses virtual machine disks from ESXi hosts similar in a manner similar to the way the vSphere Client grants access to virtual machine disks across the LAN – slower, with more overhead;

For block-based storage, option (1) appears to be the best way to go: it’s fast with very little overhead in the data channel. For those of us with grey hair, think VMware Consolidated Backup proxy server and you’re on the right track; for everyone else, think shared disk environment. And that, boys and girls, is where we come to the point of today’s lesson…

Enter Windows Server, Updates

For all of its warts, my favorite aspect of VMware Data Recovery is the fact that it is a virtual appliance based on a stripped-down Linux distribution. Those two aspects say “do not tamper” better than anything these days, so admins – especially Windows admins – tend to just install and use as directed. At the very least, the appliance factor offers an opportunity for “special case” handling of updates (read: very controlled and tightly scripted).

The other “advantage” to VMDR is that is uses a relatively safe method for accessing virtual machine disks: something more akin to VBR6’s “virtual appliance” mode of operation. By allowing the ESXi host(s) to “proxy” access to the datastore(s), a couple of things are accomplished:

  1. Access to VMDKs is protocol agnostic – direct attach, iSCSI, AoE, SAS, Fiber Channel and/or NFS all work the same;
  2. Unlike “Direct SAN Access” mode, no additional initiators need to be added to the target(s)’ ACL;
  3. If the host can access the VMDK, it stands a good chance of being backed-up fairly efficiently.

However, VBR6 installs onto a Windows Server and Windows Server has no knowledge of what VMFS looks like nor how to handle VMFS disks. This means Windows disk management needs to be “tweaked” to ignore VMFS targets by disabling “automount” in VBR6 servers and VCB proxies. For most, it also means keeping up with patch management and Windows Update (or appropriate derivative). For active backup servers with a (pre-approved, tested) critical update this might go something like:

  1. Schedule the update with change management;
  2. Stage the update to the server;
  3. Put server into maintenance mode (services and applications disabled);
  4. Apply patch, reboot;
  5. Mitigate patch issues;
  6. Test application interaction;
  7. Rinse, repeat;
  8. Release server back to production;
  9. Update change management.

See the problem? If Windows Server 2008 R2 SP1 is involved you just might have one right around step 5…

And the Wheels Came Off…

Service Pack 1 for Windows Server 2008 R2 requires a BCD update, so existing installations of VCB or VBR5/6 will fail to update. In an environment where there is no VCB or VBR5/6 testing platform, this could result in a resume writing event for the patching guy or the backup administrator if they follow Microsoft’s advice and “fix” SP1. Why?

Fixing the SP1 installation problem is quite simple:

Quick steps to do this in case you forgot are:

1.  Run DISKPART

2.  automount enable

3.  Restart

4.  Install SP1

Technet Blogs, Windows Servicing Guy, SP1 Fails with 0x800f0a12

Done, right? Possibly in more ways than one. By GLOBALLY enabling automount, rebooting Windows Server and installing SP1, you’ve opened-up the potential for Windows to write a signature to the VMFS volumes holding your critical infrastructure. Fortunately, it doesn’t have to end that way.

Avoiding the Avoidable

Veeam’s been around long enough to have some great forum participants from across the administrative spectrum. Fortunately, a member posted a solution method that keeps us well away from VMFS corruption and still solves the SP1 issue in a targeted way: temporarily mounting the “hidden” system partition instead of enabling the global automount feature. Here’s my take on the process (GUI mode):

  1. Inside Server Manager, open Disk Management (or run diskmgt.msc from admin cmd prompt);
  2. Right-click on the partition labled “System Reserved” and select “Change Drive Letter and Paths…”
  3. On the pop-up, click the “Add…” button and accept the default drive letter offered, click “OK”;
  4. Now “try again” the installation of Service Pack 1 and reboot;
  5. Once SP1 is installed, re-run Disk Management;
  6. Right-click on the “System Reserved” partition and select “Change Drive Letter and Paths..”
  7. Click the “Remove” button to unmap the drive letter;
  8. Click “Yes” at the “Are you sure…” prompt;
  9. Click “Yes” at the “Do you want to continue?” prompt;
  10. Reboot (for good measure).

This process assumes that there are no non-standard deployments of the Server 2008 R2 boot volume. Of course, if there is no separate system reserved partition, you wouldn’t encounter the SP1 failure to install issue…

SOLORI’s Take: The takeaway here is “consider your environment” (and the people tasked with maintaining it) before deploying Direct SAN Access mode into a VMware cluster. While it may represent “optimal” backup performance, it is not without its potential pitfalls (as demonstrated herein). Native access to SAN LUNs must come with a heavy dose of respect, caution and understanding of the underlying architecture: otherwise, I recommend Virtual Appliance mode (similar to Data Recovery’s take.)

While no VMFS volumes were harmed in the making of this blog post, the thought of what could have happened in a production environment chilled me into writing this post. Direct access to the SAN layer unlocks tremendous power for modern backup: just be safe and don’t forget to heed Uncle Ben’s advice! If the idea of VMFS corruption scares you beyond your risk tolerance, appliance mode will deliver acceptable results with minimal risk or complexity.

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New Security Patches for ESX/ESXi 3.5, 4.0, 4.1 and 5.0 (6/14/2012)

June 14, 2012

New patches are available today for ESX/ESXi 3.5, 4.0, 4.1 and 5.0 to resolve a few known security vulnerabilities. Here’s the run down if you’re running ESXi 5.0 standard image:

VMware Host Checkpoint File Memory Corruption

Certain input data is not properly validated when loading checkpoint files. This might allow an attacker with the ability to load a specially crafted checkpoint file to execute arbitrary code on the host. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2012-3288 to this issue.

The following workarounds and mitigating controls might be available to remove the potential for exploiting the issue and to reduce the exposure that the issue poses.

Workaround: None identified.

Mitigation: Do not import virtual machines from untrusted sources.

VMware Virtual Machine Remote Device Denial of Service

A device (for example CD-ROM or keyboard) that is available to a virtual machine while physically connected to a system that does not run the virtual machine is referred to as a remote device. Traffic coming from remote virtual devices is incorrectly handled. This might allow an attacker who is capable of manipulating the traffic from a remote virtual device to crash the virtual machine.
The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2012-3289 to this issue.

The following workarounds and mitigating controls might be available to remove the potential for exploiting the issue and to reduce the exposure that the issue poses.

Workaround: None identified.

Mitigation: Users need administrative privileges on the virtual machine in order to attach remote devices. Do not attach untrusted remote devices to a virtual machine.

Deployment Considerations

None beyond the required patch bundles and reboot information listed in the table above.

5.0 Patch Release Notes:
ESXi: http://kb.vmware.com/kb/2021031

Patch Release Information for Other Versions

3.5 Patch Release Notes:
ESX: http://kb.vmware.com/kb/2021020
ESXi: http://kb.vmware.com/kb/2021021

4.0 Patch Release Notes:
ESX: http://kb.vmware.com/kb/2021025
ESXi: http://kb.vmware.com/kb/2021027

4.1 Patch Release Notes:
ESX: http://kb.vmware.com/kb/2019065
ESXi: http://kb.vmware.com/kb/2019243

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Short Take: VMware View Client for Android, ICS Update

May 17, 2012

An updated VMware View Client for Android devices hit a the street today sporting a couple of enhancements for Google’s Android OS running the relatively new Ice Cream Sandwich (ICS) version; other improvements are for View 5.1 deployments only.

Here’s a list of the new features in the update available now on Google Play:

– Support for ICS
– Mouse support with hover, right click and scroll wheel (ICS)
– Updated look and feel and improvements for smaller screens
– New Settings dialog includes security mode settings
– Up to 2x better video playback performance
– Optimized for View 5.1
– RADIUS two factor authentication with View 5.1
– Save password option (administrator approval required) with View 5.1
– French, German, Spanish keyboard support with View 5.1

The update is a 5.32MB download, and is available free of charge.

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Quick-Take: vCenter 5.0 dies within 48-hours of Installation, Error 1000

May 1, 2012

After upgrading a View installation for a client this weekend from View 4.0 to View 5.0 all seemed well. The upgrade process took them from vSphere 4.0U2 to vSphere 5.0U1 in the bargain – about 15-20 hours of work including backups and staging. Testing and the first 24 hours of production went swimmingly with no negative reports or hiccups. (The upgrade process and spectres of dead pilots-turned-production is an issue for another blog post.)

I got a call about vCenter 5.0 dying (and then magically working again before the local admin could get to it – a couple of minutes or so.) Two mysteries, one easy, one VERY frustrating…

Mystery One – vCenter Dies and Comes Back to Life

This was the easy one: the VMware VirtualCenter Server service is set to a “300000 millisecond” recovery delay upon failure by default. The local site admin didn’t have his prayer answered, the system just recovered as planned. (Note to upgraders – set your recovery time to more or less hold-down time as your site needs – probably no less than 120000 milliseconds.)

The VMware VirtualCenter Server service terminated unexpectedly. It has done this 1 time(s). The following corrective action will be taken in 300000 milliseconds: Restart the service.

– Service Control Manager

Why would five minutes (yep, 300000 milliseconds) be a good amount of recovery time? The socratic answer is this: how long will it take for all of the vCenter log and dump files to be written based on your environment? In the case of this issue, the dump file was about 500MB in size with about another 150MB in various other logs. At a “leisurely pace” of 5 MB/sec (let’s assume the worst), that would require about two minutes of “hold time” before restart.

Mystery Two – vCenter Died. Why?

Here’s the problem: vCenter needs to be bullet proof. vCenter’s installer asks  for your environmental size during the installation and sets parameters to accommodate the basic needs. Also, during the SQL upgrade process from vCenter 4.0 to 5.0, the SQL database is set from SIMPLE (the recommended setting for vCenter) to BULK-LOGGING, but just for the duration of the upgrade. After the upgrade it’s reset back to SIMPLE.

Fast forward 48 hours. vCenter is running with a couple of hundred virtual machines in a View environment and is tracking all of that lovely host and performance data we appreciate when dealing with complex enterprise systems. It’s happily responding to View Connection Server’s request for power-ons and power-offs when all of a sudden the worst happens: it crashes!

Suddenly, 10’s of thousands of dollars worth of infrastructure is waiting for a 5 minute recovery interval and View logins requiring VM power-ons wont happen until then. All is not right in your virtual world now, buckaroo! Let’s see if Windows Event Viewer can elicit a solution:

The description for Event ID 1000 from source VMware VirtualCenter Server cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.

If the event originated on another computer, the display information had to be saved with the event.

The following information was included with the event:

Log directory: C:\ProgramData\VMware\VMware VirtualCenter\Logs.

the message resource is present but the message is not found in the string/message table

– Event Viewer, Application Log

Okay, Event ID 1000 – there’s got to be a KB on that one, but seriously, ID 1000 sound pretty generic for me to have a ton of hope. But sure enough, VMware Knowledge Base immediately coughs up KB article 1015101, applicable to vCenter 5.0. Unfortunately, vCenter Server is not installed on an IIS platform, so this is just an empty rabit hole…

Next, let’s have a look at the vCenter Server logs (thoughtfully pointed to in the Event log, above) for vCenter at-or-around the time of failure. Sure enough, there is a gzipped log with the restart time stamp available. A quick glance at the end of the log shows the following “impending doom” quality message:

--> 
--> Panic: TerminateHandler called
--> Backtrace:
--> backtrace[00] rip 000000018013deba (no symbol)
--> backtrace[01] rip 0000000180101518 (no symbol)
 ... 
--> backtrace[60] rip 00000000708f2fdf (no symbol)
--> backtrace[61] rip 00000000708f3080 (no symbol)
-->

– vCenter vpxd-X.log file

But a sobering look above the doomsday report gives us a better idea as to the real culprit: SQL execution failed. What? Did I hear you whisper “kill your DBA?” Before walking down to the DBA and calling him out for leaving you in the lurch, let’s visit the SQL logs to find out (perhaps you will have to talk to the DBA after all if your vCenter admins don’t have access to SQL logs in the environment.) Here’s what my SQL log for the vCenter database said:

05/01/2012 08:05:21,spid62,Unknown,The transaction log for database 'VIM_VCDB' is full. To find out why space in the log cannot be reused<c/> see the log_reuse_wait_desc column in sys.databases
05/01/2012 08:05:21,spid62,Unknown,Error: 9002<c/> Severity: 17<c/> State: 4.
 ...
05/01/2012 08:00:04,spid75,Unknown,The transaction log for database 'VIM_VCDB' is full. To find out why space in the log cannot be reused<c/> see the log_reuse_wait_desc column in sys.databases
05/01/2012 08:00:04,spid75,Unknown,Error: 9002<c/> Severity: 17<c/> State: 4.

– Microsoft SQL Server Log for VIM_VCDB (vCenter)

Note that something to this effect also shows up as a diagnostic message inside the vCenter log – reducing the number of times you need to traipse down to the DBA’s cubby for  a chat. Okay, that cinches it, the DBA’s been meddling in my vCenter database again – probably with some unscheduled and undocumented maintenance. We’re definitely going to have that talk now, right? Nope.

Resolution

Remember that upgrade we did 48-hours ago? As part of the upgrade process, the database is upgraded from the vCenter 4.0’s format to the more information rich vCenter 5.0 format. Along the way, an upgrade process changes the SQL database’s mode from the preferred “SIMPLE” mode to the “BULK-LOGGING” mode so that a failed upgrade can be more easily rolled-back.

Beware:

BULK-LOGGING mode can create a HUGE transaction log during a vCenter upgrade process. There are MANY posts about the TLOG filling-up during these processes, with a consensus that the TLOG needs to be allowed to grow to at least 4x the size of your vCenter database or the process will not complete.

You’ve been warned.

In the case of this upgrade, I happen to know that the TLOG was set to at least 4x of the vCenter database PRIOR to the upgrade process. In fact, during this upgrade (final stage) it grew to 1.5X of the vCenter database size. What was unknown to me – until now – is that the TLOG maximum allowed growth was reset to 500MB when the database was returned to “SIMPLE” mode. During a time of high activity (perhaps processing the last 24-hours of data) the TLOG needed to exceed that amount, couldn’t, and vCenter crashed accordingly. The simple fix is to increase the TLOG limit back to the original settings that works well for the environment.

SOLORI’s Take:

Ouch! Someone feels setup for failure. I never want to hear a customer say: “gosh, everything was great until I logged into vCenter [with the vSphere Client] and then, “all of a sudden” things went sideways” – especially when the cause is that SQL server has been silently modified with setting known to cause it to  choke, subsequently resulting in vCenter coming to a crashing halt.

VMware: if you’re modifying my database parameters POST INSTALL you need to WARN ME or post it in the install or upgrade docs. I’ve combed them and can’t find it… let’s get the upgrade process modified so that the database settings are restored after the database is returned to SIMPLE mode, okay?

Updated 05/02/2012: Corrected intro grammar. Link to TLOG upgrade issue added.

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Quick Take: Syslog Stops Working after Upgrade to ESXi 5.0 Update 1

March 24, 2012

If you’ve recently upgraded your ESXi from 5.0 build 456551 and were logging to syslog, it’s possible that your events are no longer being received by your syslog server. It seems that there was a “feature” in ESXi 5.0 build 456551 that allowed syslog to escape the ESXi firewall regardless of the firewall setting. This could be especially problematic if your upgraded from ESXi 4.x where there was no firewall configuration needed for syslog traffic.

VMware notes that syslog traffic was not affected by the ESXi firewall in v5 build 456551. See KB2003322 for details.

However, in ESXi 5.0 Update 1, the firewall rules definitely applies and if you were “grandfathered-in” during the upgrade to build 456551: check your syslog for your ESXi 5 servers. If your no longer getting syslog entries, either set the policy in the host’s Configuration->Security Profile->Properties… control panel:

Enabling syslog traffic in the ESXi firewall within the vSphere Client interface.

 

Or use ESXCLI to do the work (especially with multiple hosts):

esxcli network firewall ruleset set –ruleset-id=syslog –enable=true

esxcli network firewall refresh

That will take care of the “absent” syslog entries.

SOLORI’s Take: Gotcha! As ESXi becomes more like ESX in terms of provisioning, old-school ESXiers (like me) need to make sure they’re up-to-speed on the latest changes in ESXi. Ashamed to admit it, but this exact scenario got me in my home lab… Until I stumbled onto KB2003322 I didn’t think to go back and check the ESXi firewall settings – after all, it was previously working 😉

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Quick Take: VMware ESXi 5.0, Patch ESXi50-Update01

March 16, 2012

VMware releases ESXi 5.0 Complete Update 1 for vSphere 5. An important change for this release is the inclusion of general and security-only image profiles:

Starting with ESXi 5.0 Update 1, VMware patch and update releases contain general and security-only image profiles. Security-only image profiles are applicable to new security fixes only. No new bug fixes are included, but bug fixes from earlier patch/update releases are included.

The general release image profile supersedes the security-only profile. Application of the general release image profile applies to new security and bug fixes.

The security-only image profiles are identified with the additional “s” identifier in the image profile name.

Just a few of the more interesting bugs fixed in this release:

PR 712342: Cannot assign VMware vSphere Hypervisor license key to an ESXi host with pRAM greater than 32GB

PR 719895: Unable to add a USB device to a virtual machine (KB 1039359).

PR 721191: Modifying snapshots using the commands vim-cmd vmsvc/snapshot.remove or vim-cmd vmsvc/snapshot.revert
will fail when applied against certain snapshot tree structures.

This issue is resolved in this release. Now a unique identifier, snapshotId, is created for every snapshot associated to a virtual machine. You can get the snapshotId by running the command vim-cmd vmsvc/snapshot.get <vmid>. You can use the following new syntax when working with the same commands:

Revert to snapshot: vim-cmd vmsvc/snapshot.revert <vmid> <snapshotId> [suppressPowerOff/suppressPowerOn]
Remove a snapshot: vim-cmd vmsvc/snapshot.remove <vmid> <snapshotId>

PR 724376: Data corruption might occur if you copy large amounts of data (more than 1GB) from a 64-bit Windows virtual machine to a USB storage device.

PR 725429: Applying a host profile to an in-compliance host causes non-compliance (KB 2003472).

PR 728257: On a pair of HA storage controllers configured for redundancy, if you take over one controller, the datastores that reside on LUNs on the taken over controller might show inactive and remain inactive until you perform a rescan manually.

PR 734366: Purple diagnostic screen with vShield or third-party vSphere integrated firewall products (KB 2004893)

PR 734707: Virtual machines on a vNetwork Distributed Switch (vDS) configured with VLANs might lose network connectivity upon boot if you configure Private VLANs on the vDS. However, disconnecting and reconnecting the uplink solves the problem.This issue has been observed on be2net NICs and ixgbe vNICs.

PR 742242: XCOPY commands that VAAI sends to the source storage device might fail. By default, XCOPY commands should be sent to the destination storage device in accordance with VAAI specification.

PR 750460: Adding and removing a physical NIC might cause an ESXi host to fail with a purple screen. The purple diagnostic screen displays an error message similar to the following:

NDiscVlanCheck (data=0x2d16, timestamp=<value optimized out>) at bora/vmkernel/public/list.h:386

PR 751803: When disks larger than 256GB are protected using vSphere Replication (VR), any operation that causes an internal restart of the virtual disk device causes the disk to complete a full sync. Internal restarts are caused by a number of conditions including any time:

  • A virtual machine is restarted
  • A virtual machine is vMotioned
  • A virtual machine is reconfigured
  • A snapshot is taken of the virtual machine
  • Replication is paused and resumed

PR 754047: When you upgrade VMware Tools the upgrade might fail because, some Linux distributions periodically delete old files and folders in /tmp. VMware Tools upgrade requires this directory in /tmp for auto upgrades.

PR 766179: ESXi host installed on a server with more than 8 NUMA nodes fails and displays a purple screen.

PR 769677: If you perform a VMotion operation to an ESXi host on which the boot-time option “pageSharing” is disabled, the ESXi host might fail with a purple screen.

Disabling pageSharing severely affects performance of the ESXi host. Because pageSharing should never be disabled, starting with this release, the “pageSharing” configuration option is removed.

PR 773187: On an ESXi host, if you configure the Network I/O Control (NetIOC) to set the Host Limit for Virtual Machine Traffic to a value higher than 2000Mbps, the bandwidth limit is not enforced.

PR 773769: An ESXi host halts and displays a purple diagnostic screen when using Network I/O Control with a Network Adapter that does not support VLAN Offload (KB 2011474).

PR 788962: When an ESXi host encounters a corrupt VMFS volume, VMFS driver might leak memory causing VMFS heap exhaustion. This stops all VMFS operations causing orphaned virtual machines and missing datastores. vMotion operations might not work and attempts to start new virtual machines might fail with errors about missing files and memory exhaustion. This issue might affect all ESXi hosts that share the corrupt LUN and have running virtual machines on that LUN.

PR 789483: After you upgrade to ESXi 5.0 from ESXi 4.x, Windows 2000 Terminal Servers might perform poorly. The consoles of these virtual machines might stop responding and their CPU usage show a constant 100%.

PR 789789: ESXi host might fail with a purple screen when a virtual machine connected to VMXNET 2 vNIC is powered on. The purple diagnostic screen displays an error message similar to the following:

0x412261b07ef8:[0x41803b730cf4]Vmxnet2VMKDevTxCoalesceTimeout@vmkernel#nover+0x2b stack: 0x412261b0
0x412261b07f48:[0x41803b76669f]Net_HaltCheck@vmkernel#nover+0xf6 stack: 0x412261b07f98

You might also observe an error message similar to the following written to VMkernel.log:

WARNING: Vmxnet2: 5720: failed to enable port 0x2000069 on vSwitch1: Limit exceeded^[[0m

SOLORI’s Take: Lions, tigers and bears – oh my! In all, I count seven (7) unique PSD bugs (listed in the full KB) along with some rather head-scratching gotchas.  Lots of reasons to keep your vSphere hosts current in this release to be sure… Use Update Manager or start your update journey here…