cancel
Showing results for 
Search instead for 
Did you mean: 

AVVI Restore of Differential Backup Restores ONLY Differential Data

Sublaner
Level 4

Hello,

I use BE2010 R3 in a Win 2k8 VMware 4.0 VM to back up similar VMs using the AVVI through the VCenter. Backup policies perform weekly full and daily differential backups of all VMs, one job for each VM.

This is a new issue since installing BE2010 R3 SP4 and HF 212812.

On a test suite, when I try to restore a VM to its original location from a Differential backup (with "Delete existing..."), I get the warning stating that the full VM will be restored (as expected), the job runs and reports "Successful", however the restore of the 50+ GB VM runs in about 8 minutes and reports a byte cound roughly equal to the size of the Differential backup job (1.5GB or so). The job history reports that all three virtual disks were restored, but the VM fails to start with "operating system not found".

Re-trying the job, this time the byte count is less than 100 kB and the history reports only ONE vmdk was restored - still "Successful", though. Icing on the cake is, when I try to restore the VM from the Full backup that is the parent to the Differential I get the same result - "Successful" restore, 42,614 bytes Byte Count, and only one vmdk

Restoring the VM from an earlier or later Full backup works - so it seems that the Differential is poisoning the parent Full backup at some point.

I installed Hotfix 212812 because one of my servers was producing the error described in  http://www.symantec.com/docs/TECH201706. I preferred the error!!

Has anyone else seen this, who can maybe tell me what is going on?

1 ACCEPTED SOLUTION

Accepted Solutions

Sublaner
Level 4

The problem I saw with HF 212812 (https://support.symantec.com/en_US/article.TECH212812.html) is that

1. Restore of VM from the Differential backup restores only the Differential data, but restore still reports "successful".

2. After this has been tried once, a second attempt still reports successful but even LESS data is restored - apparently only one "shell" vmdk for me.

3. WORST OF ALL, running a restore of the Diff seems to "poison" the WF: once you have tried to restore from the Differential, its parent Weekly Full backup also becomes unusable for full VM restore, restoring "shell" data as in (2) above.

Normal file/folder restores from the Diffs still work.

The "Resolved issue" that I installed HF 212812 for was: "Backup Exec 2010 R3: AVVI restore from an incremental backup set of a virtual machine fails with error - Failed to mount one or more virtual disk images (TECH201706)". The failure was better.

My testing is done. I believe this hotfix is defective, and we will not deploy it.

View solution in original post

4 REPLIES 4

Sublaner
Level 4

... and I have duplicated this scenario with two different virtual machines.

Colin_Weaver
Moderator
Moderator
Employee Accredited Certified

Are you using removable storage to store the full and differential backup sets on different disks that are not always online?

 

Basically a differential restore needs that the recovery chain is all online at the same time (and on the original drive letter), which more or less means the differential sets will have to be on same cartridge as full if removable disk storage is being used.

Also just for info unlike a file system backup, differential restores of VMs in VMware restore the differential first (into an emopty snapshot) then the full (into another snapshot I believe) and then a process within the vddk will re-assemble the snapshots to recombine the backup sets. It sounds like your differential is being restored but then we cannot locate the full.

 

Noet if this is tape or fixed disk storage then the above does not apply. 

 

BTW don't be tempted to go to latest versions of Backup Exec without checking the compatibility list for the newre version as ESX 4.x support is not available in the newest version of Backup Exec

 

 

 

Sublaner
Level 4

Thanks Colin, the storage is permanent - virutal disks attached to the Backup Server VM.

The "diff restore to empty snapshot" explanation clears up one puzzle: browing the datastore after the first attempt I found three "appropriately sized" vmdks but not all the supporting files.

More detail: I ran one full backup after the Differential I tested with. Before restoring I shut down the VM, renamed it, deleted it from inventory, and moving the 'failed' VM folder to another data store. I don't know what else I could do to gve BE a clean slate to restore to.

Does the differential look to the "last" full backup even if it occurs later, by any chance? We have always thought not...

Thanks also for the warning about upgrading. We are planning to patch a number of systems to ESX 4.1 to extend their life for a a couple years, and upgrade Backup Exec at the same time. BE 2015 is 'newest' so I will check compatability for BE 2014.

Sublaner
Level 4

The problem I saw with HF 212812 (https://support.symantec.com/en_US/article.TECH212812.html) is that

1. Restore of VM from the Differential backup restores only the Differential data, but restore still reports "successful".

2. After this has been tried once, a second attempt still reports successful but even LESS data is restored - apparently only one "shell" vmdk for me.

3. WORST OF ALL, running a restore of the Diff seems to "poison" the WF: once you have tried to restore from the Differential, its parent Weekly Full backup also becomes unusable for full VM restore, restoring "shell" data as in (2) above.

Normal file/folder restores from the Diffs still work.

The "Resolved issue" that I installed HF 212812 for was: "Backup Exec 2010 R3: AVVI restore from an incremental backup set of a virtual machine fails with error - Failed to mount one or more virtual disk images (TECH201706)". The failure was better.

My testing is done. I believe this hotfix is defective, and we will not deploy it.