Large VIB file on a small static server

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Re: Large VIB file on a small static server

Veeam Logoby Zew » Tue Aug 23, 2016 8:13 pm

They are fraged, I was going to clean that up when I figured out all the fun stuff about CBT and changed blocks and VM hole punching. Would really fragmented discs cause this? I figured it would cause this after I clean all the fragmentation up.
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Re: Large VIB file on a small static server

Veeam Logoby foggy » Wed Aug 24, 2016 11:06 am

Fragmentation affects the amount of data to back up, due to the reason I've mentioned above - if the small changes are scattered along multiple blocks instead of being written into a single one, then more data needs to be read and transferred.
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Re: Large VIB file on a small static server

Veeam Logoby Zew » Thu Aug 25, 2016 3:01 pm

Perfect thanks for all the info guys... defragging was in my "things to do" I'll report back what I find after its all done, I'm expecting a big VIB after all the defrag, and then hopefully smaller ones from then.
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Re: Large VIB file on a small static server

Veeam Logoby folerx » Wed Sep 14, 2016 5:39 pm

summary, what to do to make vib smaller as possible?
1. turn of last access time help?
2. turn off defragmenter help?
3. disable 8.3 name creation help?
4. ...
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Re: Large VIB file on a small static server

Veeam Logoby foggy » Thu Sep 15, 2016 10:35 am

Disabling/reducing any activity resulting in data change on the source VM will help to decrease the size of the increment.
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[MERGED] Windows server Dedupe and Veeam

Veeam Logoby GreenEnvy » Mon Jan 09, 2017 2:48 pm

This isn't an error or technical issue, more just general question.

We have Windows server 2012 r2 dedupe enabled on all of our file servers. We have Veeam setup using reverse incremental, keeping 14 restore points, running at 7pm nightly.
This has been working well for us for a few years now.

Every once in a while, we get a huge reverse incremental, and we're wondering if the Windows dedupe might be the cause.

For example, the file server that has this issue has 3 drives. 55GB OS drive, 1.8TB shared drive, and 2.5TB shared drive. The main backup file is right around 4TB for this server. Nightly restore points are usually in the 3-60GB range.
This past saturday night, the restore point is 861GB and took 33 hours to complete (normally under 2). We've looked into the antivirus on the server, but it didn't run any scans over the 48 hours leading upto this. We've looked at new/modified files on the server, but can only account for around 30GB of changes. We've had this happen a few times in the past, also seemingly on weekends when almost no one is working. It's only once every few months usually though, not a weekly thing.

Windows dedupe background optimization is set to constantly run in the background every day, all day. Throughput optimization runs nightly from 1am-5am. On Saturday and Sunday, it runs a garbage collection and a scrubbing jobs around 3am.
Looking at those dedupe logs, the garbage collection and scrubbing jobs only took a few minutes to run, so I can't see how they'd be creating so many changed blocks. The timing of it though is suspicious, since the garbage and scrubbing run on weekends, and these large files seem to happen on weekends.

I saw another thread speculating defragging might be causing it, or antivirus, or dedupe. I also saw an old best practices thread that said to use forward incrementals with Veeam if you have dedupe, but this seemed to be talking about deduping the Veeam backup files.

Does anyone else with a similar setup experience this? It's not a problem, but we'd love to know what's causing it.
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Re: Large VIB file on a small static server

Veeam Logoby foggy » Mon Jan 09, 2017 3:00 pm

Most likely Windows Deduplication activity (garbage collection/scrubbing tasks in particular) are indeed the culprits of the observed behavior.
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Re: Windows server Dedupe and Veeam

Veeam Logoby skrause » Tue Jan 10, 2017 6:43 pm 1 person likes this post

The issue is likely being caused by the periodic garbage collection. Using forward incremental and setting the full to happen the next backup interval after the garbage collection is scheduled is the only way I have found to get around the large increment issue.

Setting your Veeam job to ignore deleted blocks helps quite a bit, but the chunklets that get cleaned up by windows dedupe still end up creating a lot of changed blocks for Veeam since they don't excatly align with the Veeam blocks so you get enough overlap that creates the need to back up blocks that have had some of their data change.
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Re: Windows server Dedupe and Veeam

Veeam Logoby Delo123 » Wed Jan 11, 2017 8:09 am

Well said Skrause :) Yes, that's the nature of deduping storage. Forward incremental and good timing is certainly the way to go....
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[MERGED] why are incremental backups so big?

Veeam Logoby tym » Thu Mar 02, 2017 12:07 pm

Hi,

we have incremental backups that are between 200 and 500 gb per day. I cant believe that users change/create 500 gb of data per day, considered that we only backup changed blocks. Is there any chance to see the details/contents of the incremental backups?

Best,
Tim
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Re: why are incremental backups so big?

Veeam Logoby DGrinev » Thu Mar 02, 2017 12:47 pm

Hi Tim,

Incremental file size depends on different processes such as file relocation or defragmentation causes block modifications on the file system.
Please review this thread for more information.

Thanks!
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[MERGED] incremental backup files are huge

Veeam Logoby StefanVM » Tue May 23, 2017 8:11 am

Hi dear Veeam community,

I have the issue that the incremental backup files of one of ours servers is extremely large.
It's a rather small server and the full backup size is about 40 GB. The incremental backup files are usually about 10 GB (going up to 20 GB on some days), which is a very large percentage.
For the other servers, the incremental backup file size is about 5% of the full backup, but depending on the servers also lower or higher on some days, rarely over 10%

The server with the large backup files doesn't have much activity, It is only used as a file server. As we made backups with a different system so far, the file size was never that large.
One aspect that may be important is that this is the only server having a VHD dynamic disk configuration. Could that be the reason for the problem?


- Stefan
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Re: incremental backup files are huge

Veeam Logoby DGrinev » Tue May 23, 2017 11:15 am

Hi Stefan,

There are many reasons for an incremental file size changing such as dirty blocks, file relocation, fragmentation and other things that change data blocks.
Please review this discussion for additional information. Thanks!
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