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iroche
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Question on Synthetic and Full backups

Post by iroche »

Hi Guys,

Just installed our new Veeam server with with 17TB of storage attached, My first job is to configure a job for our virtual file server this contains 7TB of data. I ran a full last week to test and it was very impressive it completed in around 36 hours with dedup and compression getting it down to a vbk of 5.8TB in size . Soooo the schedule is as follows Synthtic will run for 3 Saturdays of the month and incremental from mon-fri .The weekly synthetic will be sent to tape (tapes will be over written every 3 weeks) .On the last Saturday of the Month I will run a full and this will be sent to tape and kept indefinitely. My two main questions are around the "Transform previous full backup chains into rollbacks" which I want to enable as I only want one full backup on disk at anytime due to the size of it (5.8TB). I want to know can anyone with experience tell me how long this could take for files of this size and will it be a big overhead on the backup server. The incremental should be quiet small the majority of access to the server is of the read variety ...

Second question is around scheduling from what I can see I can only choose to schedule the Synthetic and Fulls on certain days. If I want to run the Synthetic job 3 Saturdays of the Month and the Full on the last what will happen on the last Saturday will the Full or Synthetic run or both? If you guys need anymore details let me know. Serious product by the way its going to make my life a hell of allot easier !

My first post :D
Thanks in advance
Ian

Vitaliy S.
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Re: Questin on Synthetic and Full backups

Post by Vitaliy S. »

iroche wrote:My two main questions are around the "Transform previous full backup chains into rollbacks" which I want to enable as I only want one full backup on disk at anytime due to the size of it (5.8TB). I want to know can anyone with experience tell me how long this could take for files of this size and will it be a big overhead on the backup server. The incremental should be quiet small the majority of access to the server is of the read variety ...
Provided that you're going to send only full backups to tape, why don't you want to choose Reversed Incremental backup mode?

If you decide to go with this mode, you'll always have only single VBK file. Additionaly as far as storage space is concerned, please take a look at this topic, which describes how retention policy for Forward Incremental backup mode actually works.

That said, Reversed Incremental mode seems to be a better option in your scenario.

As to the transform time question, then transform is definitely not fast operation - very large amounts of data, and lots of I/O operations, so make sure you have a decent hardware for that.
iroche wrote:Second question is around scheduling from what I can see I can only choose to schedule the Synthetic and Fulls on certain days. If I want to run the Synthetic job 3 Saturdays of the Month and the Full on the last what will happen on the last Saturday will the Full or Synthetic run or both?
On the last Saturday you will only see active Full backup job run. With the schedule described above, no Synthetic backups will be made.

iroche
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Re: Questin on Synthetic and Full backups

Post by iroche »

Vitaliy S. wrote: Provided that you're going to send only full backups to tape, why don't you want to choose Reversed Incremental backup mode? .
TO be honest on reflection it does seem like the best and most straight forward option, I was in the mindset of following the User Guide which suggests forward incremental are best for disk-disk-tape scenarios but I think what you suggested will fit well.
Vitaliy S. wrote: If you decide to go with this mode, you'll always have only single VBK file. Additionaly as far as storage space is concerned, please take a look at this topic, which describes how retention policy for Forward Incremental backup mode actually works. That said, Reversed Incremental mode seems to be a better option in your scenario..

Ok this post makes it more clear looks like I will have a bigger restore chain if I go down this route will allot more disk eaten up. I'm going to go with the Reversed Incremental it fits the bill in terms of what we need to get on tape weekly, ease of restore and a smaller disk footprint. We should be bale to keep a fair amount of restore points as I expect the vibs to be fairly small.
Vitaliy S. wrote:As to the transform time question, then transform is definitely not fast operation - very large amounts of data, and lots of I/O operations, so make sure you have a decent hardware for that.

Id imagine the transformation of the 5.8TB file would significantly increase the backup and dump to tape window as well as having a large impact on the local disks.

Thanks for clearing this one up .

iroche
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Re: Question on Synthetic and Full backups

Post by iroche »

Just a quick one on this we have an issue with trying to backup the vbk file to tape with the reverse incremental option the vbk is updated as the incremental finishes each night. This seems to have caused the backup job to fail which was kicked off after the full completed at the weekend. This machine is over 4TB in size so it takes a few days to get onto tape. The error it throws up is "Final error: 0xe000fe36 - Corrupt data encountered. See the job log for details". Do you think we need to change the backup mode back to forward incremental ? We basically need to get a copy of this 4TB vm onto tape every week and keep the 4th week on tape indefinitely . I was going to run Synthetic fulls for three weeks then on the last weekend run a active full. The reverse incremental option seemed the most straight forward but if it doesnt allow us to get the vbk file onto tape we may have to rework it. I have kicked off a tape backup again with the solution outlined below I will update with the results. If its going to fail it will happen tonight after the incremental has run.

This was the fix for the job errors as suggested by Symantec - http://www.symantec.com/business/suppor ... 6825520236


Any opinions?

Vitaliy S.
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Re: Question on Synthetic and Full backups

Post by Vitaliy S. »

iroche wrote:Do you think we need to change the backup mode back to forward incremental ? We basically need to get a copy of this 4TB vm onto tape every week and keep the 4th week on tape indefinitely.
Well...you can do that, but I've thought that you you're limited with free space on your target datastore.

Reversed Incremental backup mode will allow you to have only single VBK file, while with Forward Incremental you'll have more. Please take a look at our F.A.Q. topic where you can find a comparison of these two modes, that should help you to choose.
iroche wrote:The reverse incremental option seemed the most straight forward but if it doesnt allow us to get the vbk file onto tape we may have to rework it.
Hard to say what went wrong, but I can say for sure that our customers have always been copying VBK files to tapes successfully.

How did you setup your BE backup job? You know...we've got a whitepaper that explains how to tie both solutions together. This document is available through our sales people and support team.

iroche
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Re: Question on Synthetic and Full backups

Post by iroche »

How did you setup your BE backup job? You know...we've got a whitepaper that explains how to tie both solutions together. This document is available through our sales people and support team.

Its a standard job the vbk is written to disk on the backup server, I then have a scripted trigger to kick off the backup of the vbk file on the Saturday (I have excluded all other files from being backed up).I already tested the backup of a standalone full backup and it worked fine, so I know the operation does work. I am thinking its the fact that when the BE job is running the veeam incremental runs which in turn modifies the vbk file and Backup exec possibly doesn't like this?

Vitaliy S.
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Re: Question on Synthetic and Full backups

Post by Vitaliy S. »

iroche wrote:I am thinking its the fact that when the BE job is running the veeam incremental runs which in turn modifies the vbk file and Backup exec possibly doesn't like this?
Correct. With Reversed Incremental backup mode the VBK file gets updated with VM changes during the backup job run. In order not to have such an overlap, you may want to use post-backup job script to trigger BE tape job.

iroche
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Re: Question on Synthetic and Full backups

Post by iroche »

Correct. With Reversed Incremental backup mode the VBK file gets updated with VM changes during the backup job run. In order not to have such an overlap, you may want to use post-backup job script to trigger BE tape job.
Thanks for clarify this, I already have the backup to tape triggered the issue is it takes a few days to get the 5TB onto tape and the job is scheduled to run every night. Ill change the strategy to a forward incremental with the synthetic full to run on a Saturday I can then back this up to tape and since it wont be modified in this mode when the incremental runs it will backup without any issue.

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