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Do VMWare MS-Flashbackups check free space on the LUN before starting a snapshot?

Level 6

NetBackup Enterprise running on 2008R2x64.

I've got a couple of VMWare machines that I've been backing up via clients and was thrilled to see that due to recent changes by the SAN Admin, all the preliminary tests inside the NetBackup GUI for a VMWare Flash Backup seemed to work (no error returned).  So imagine my surprise when the backup failed with a 156 and at the SAN Admin reports that I blew the available space on that LUN and irretrivably corrupted the exsiting VMDKs....

At least it was the only machine on that LUN and I still have the last client based backup onsite and they're willing to rebuild the VM enough to let me restore it...


But I'd hope (and perhaps this is fixed in 7.5) that there is some sort of sanity check of the free space in the LUN before the snapshot starts....or do I need to submit this as an Enhancement Request?


Level 6
Partner    VIP    Accredited Certified

"SAN Admin reports that I blew the available space on that LUN and irretrivably corrupted the exsiting VMDKs...."

I find it hard to believe that a snapshot (not YOU) will cause this kind of corruption!

I have not seen any option to check for available space. NBU 7.5 documentation is available for download:

Level 4

There are chances that LUN reported currupt was thin device and due to space crunch on storage device it may happen.

Level 5
Employee Accredited Certified

NetBackup currently does not check the space availability on the LUN prior to making a snapshot.  The same way that if you attempted to create a Snapshot using Virtual Center, NetBackup has the same limitations.

I would definitely recommend send a Enhancement request as it doesn't hurt to ask.

Level 6

We're considering a 7.1 to 7.5 upgrade but have to do a hardware refresh at one site first (we have two different sites / masters and one of them is still 32 bit) and have a ugly change control process to satisfy...not to mention that this mess isn't creating any new friends for NetBackup in Upper Management...

Level 6

I'll find the link for enhancement requests and send it in.  Restores check for available space so there has to be a way to leverage that same API when doing a backup.

I've also opened a ticket with Support to see what they say about the errors I'm getting.  But we're getting close to just building a new VM and doing a clean install of the application...if I can get some bandwidth from that company to help us reconnect to the existing database...

Not applicable

There was a silent rule around that 10% free space on a datastore was what might be needed for snapshot, vswp, logs etc.

Excellent tool "rvtools" gives you single pane of glass in tabulated form over your entire vmware infrastructure. In particular the Health tab. Could help you with other datastores.

You should also setup alarms for thresholds reached on your datastores - or modify the existing levels.