SEsparse Snapshot Data Inconsistencies

SEsparse snapshot data inconsistencies have been reported with databases. This is one of last week’s more interesting knowledge base articles. This is not something to take lightly. The knowledge base article is titled ‘Virtual Machines running on an SEsparse snapshot may report guest data inconsistencies (59216)’ . The good news is that it has been resolved and there is also a workaround. Please click on the link to see the entire kb article that includes the workaround.

Symptoms

  • Applications such as databases may report block-level data inconsistency.
  • Guest operating systems may report file system metadata inconsistencies
  • The VM fails to boot when it is running from an SEsparse snapshot.

SEsparse is a snapshot format introduced in vSphere 5.5 for large disks, and is the preferred format for all snapshots in vSphere 6.5 and above with VMFS-6.

Cause

VMware has identified an issue in SEsparse VM snapshots that can cause data inconsistencies.

This issue occurs when a VM is running on an SEsparse snapshot and experiences a burst of non-contiguous write IO in a very short period of time.

Impact / Risks

Impacted Configurations:

  • VMFS-5 or NFS Datastores: VMs with virtual disks >2TB and snapshots. On VMFS-5 and NFS, the SEsparse format is used for virtual disks that are 2 TB or larger
  • VMFS-6 Datastores: VMs with snapshots. SEsparse is the default format for all snapshots on VMFS-6 datastores.

Impacted vSphere releases:

  • vSphere 6.5 and above with VMFS-6 and any VM with snapshots.
  • vSphere 5.5 and above when VMs with virtual disks >2TB have snapshots.

Note: VMFS-5 or NFS datastores only use SEsparse with snapshots when virtual disks exceed 2 TB in size or SEsparse is explicitly configured.

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Resolution

The issue is resolved the following releases:

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Last Week’s Most Interesting VMware KBs

Last Week’s VMware KBs of Interest for week ending May 27th, 2018

These are the KBs I found of the most interest to me in my environment.  They might be of interest to you as well.

vCenter Server Appliance Management Interface might not display the vCenter Server 6.7.0a patch  

If you were one of the psychos that likes to upgrade to the bleeding edge as soon as it goes GA then this one may have bitten you. There is currently no resolution but there is a workaround. 

 

While migrating from a Windows vCenter Server to a 6.5 vCenter Appliance, one or more services fail to start

If you utilize hosts files instead of a valid forward and reverse dns entry then this one my rear its ugly head during your migration.  There is a workaround with two parts.  You really should use the first part of the workaround and skip the second part which continues the use of hosts files.  This is why you are in this mess in the first place.  Please check it out.

Upgrading VM Virtual Hardware through Update Manager 6.x fails on Linux Virtual Machines

This is a known issue and there is no resolution currently.  Please see KB for a list of the symptoms to see if you are truly affected.

Hopefully these are helpful and hopefully reading these will prevent some issues before they happen. Please read the full list by clicking the picture below or the source link.

Get in there!

 

VMware Support News, Alerts, and Announcements

Source: VMware Support Insider

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Deleting Orphaned Virtual Desktops In VMware View

If you’ve ever managed a VMware View vdi environment for a period of time sooner or later you will have to manually delete orphaned virtual desktops.  Although VMware provides KB 1008658 that explains this procedure.  It is lacking in clarity especially for first time VMware View admins.

As we all know our friend Google provides if you only ask.  I have found 2 other blogs that do very good job of taking KB 1008658 and parsing it down to a more concise version.  My intention was to do this myself but why reinvent the wheel when you can just pay homage to it.

Here are the 2 blog post links:

http://terenceluk.blogspot.com/2013/02/manually-deleting-orphaned-andor-stale.html

http://luckyblogshere.blogspot.com/2011/06/removing-vms-from-adam-database.html

 

The summarized steps for deleting an orphaned virtual desktop in VMware View is:

  1. Stop provisioning on the offending vdi pool (optional but my experience is that it is essential especially with very busy non-persistent pools with)
  2. Remove orphaned virtual desktop from ADAM database
  3. Remove all relevant entries for the orphaned vdi in the SQL Composer database
  4. Delete corresponding computer object out of Active Directory
  5. Enable provisioning once again on the pool

Please see the other blog posts for exact details.

Hopefully seeing more than one example really helps in understanding the necessary steps.

 

Note:  Edited 9/29/17 to remove a broken link

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