Slow backup to tape - windows dedupe?

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Slow backup to tape - windows dedupe?

Veeam Logoby bucoops » Wed Oct 19, 2016 3:42 pm

Good Afternoon, I'm trying to track down why I'm getting very slow transfer speeds recently. I run two D2D jobs -

Daily continuous incremental keeping 7 restore points and then a separate weekly full.

Then each day the daily is written to tape so it has to convert the chain into a full, and then once a week the weekly is copied to a separate tape pool.

Library is an MSL2024 with LTO6.

The daily tape run I get ~45MB/Sec, the weekly I get ~113MB/Sec.

I used to get much better performance on the daily - I didn't really notice the change in speed for a while but could it be because one of the VMs now has dedupe enabled?

thanks :)
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby v.Eremin » Wed Oct 19, 2016 3:50 pm

By dedupe you refer to Windows Server Deduplication? If so, that can pretty much explain the difference in current and previous speeds, as now data needs to rehydrated prior to being archived. Thanks,
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby bucoops » Wed Oct 19, 2016 4:00 pm

Hi, Ah ok - I was under the impression that veeam and windows dedupe complemented each other? https://www.veeam.com/blog/how-to-get-u ... ation.html or is that purely for the D2D?

thanks
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby v.Eremin » Wed Oct 19, 2016 5:04 pm

Not sure whether I follow you here.

Backup to tape job takes data stored on disk and archives it to tape. Since in your case data is stored on disk in deduplicated state, it has to be rehydrated (or returned to its original state in other words) before it can be written to tape. Thus, the performance decrease.

Thanks.
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby bucoops » Wed Oct 19, 2016 5:44 pm

Hi - so backup to disk is deduped, but to tape is not? But otherwise compressed? Is there not a way of keeping it deduped?

thanks
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby v.Eremin » Wed Oct 19, 2016 5:46 pm

Getting back to original question - by dedupe you refer to Windows Server Deduplication or VB&R backup job one?
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby bucoops » Wed Oct 19, 2016 5:49 pm

Windows, yes. We have an enourmous amount of very similar files that aren't accessed often but need to be available - so it works very well for us saving nearly a terabyte of space.
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby v.Eremin » Thu Oct 20, 2016 11:48 am

So backup to disk is deduped, but to tape is not?

Correct, because Windows Server Deduplication mechanism does not cover tapes, only files stored on a file system.

But otherwise compressed?

Data can be compressed by your tape device, if it supports that.

Is there not a way of keeping it deduped?

Nope, as I've mentioned already, data needs to be rehydrated before being written to tapes.

Thanks.
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby bucoops » Sat Oct 29, 2016 10:24 am

Sorry for the delay in replying. I think my issue is a combination - when I run the weekly backup that does a full then copies it to tape. Currently 5 hours to disk and then 6 hours for the copy to tape.

Whereas the daily incremental takes half an hour to save the changed data, then over 6 hours for the merge. Then a further 9 hours to send a full backup to tape.

The data is the same so it's the method that's adding 4 hours to the daily backup. I think I need to invest in a load more disk space and change to a full daily backup instead of incremental as well?
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby v.Eremin » Mon Oct 31, 2016 4:08 pm

I'm slightly confused by your current jobs' implementation and goal you're trying to achieve. So, correct me if I'm wrong:

- You have two backup jobs (daily and weekly ones)
- Both process the same set of VMs
- Both use the same mode (forward incremental with active full)
- Both are pointed to the same repository
- Both get archived to tapes
- Jobs get archived by different backup to tape jobs
- One tape job that processes weekly backup job copies only full backups
- Another tape job that processes daily backup job copies both full and incremental backups
- Incremental cycle of tape job that processes daily backup job much longer that full cycle of tape job that process weekly backup job?

(And deduplication is enabled where? Repository server, backup server, inside VM that gets backed up by two backup jobs?)

Thanks.
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby bucoops » Tue Nov 01, 2016 10:00 am

Hi, sorry if I've been unclear - still quite new to backups in general and Veeam. I've added notes below

v.Eremin wrote:I'm slightly confused by your current jobs' implementation and goal you're trying to achieve. So, correct me if I'm wrong:

- You have two backup jobs (daily and weekly ones) - YES
- Both process the same set of VMs - YES
- Both use the same mode (forward incremental with active full) - NO - the daily runs forward incremental keeping 5 restore points, the weekly is a simple full
- Both are pointed to the same repository - YES
- Both get archived to tapes - YES
- Jobs get archived by different backup to tape jobs - YES - as you don't have a daily GFS option
- One tape job that processes weekly backup job copies only full backups - YES
- Another tape job that processes daily backup job copies both full and incremental backups - NO - it builds a full from the incrementals (each incremental is ~20-30GB so not huge)
- Incremental cycle of tape job that processes daily backup job much longer that full cycle of tape job that process weekly backup job? - YES

(And deduplication is enabled where? Repository server, backup server, inside VM that gets backed up by two backup jobs?) - On one inside VM.

Thanks.
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby v.Eremin » Tue Nov 01, 2016 11:22 am

it builds a full from the incrementals (each incremental is ~20-30GB so not huge)

Ok, so it's full backup cycle in both cases (not incremental versus full): daily job synthesizes virtual full backup directly on tapes, weekly one copies full backup to tapes. Due to the differences in nature (direct copy against synthesized restore point creation) those jobs cannot be compared fairly.

You can switch daily job to reversed incremental mode, so that latest restore point (which is always a full backup) gets directly archived to tapes on daily basis. Otherwise, if the proposed scenario is not applicable, you might want to open a ticket with our support team and investigate whether the performance of virtual full backup can be improved somehow.

(And deduplication is enabled where? Repository server, backup server, inside VM that gets backed up by two backup jobs?) - On one inside VM.

Then, disregard what I've written previously, since I was talking about enabling deduplication on top of backup repository. Usage of deduplication inside VM should result in bigger increments, that's it.

Thanks.
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby bucoops » Fri Nov 11, 2016 10:10 am

Hi,

Thank you - I've now removed dedupe from the server and whilst it's costing me a lot more disk space, I'm now down to sub-3 hour runs so I'll take that!

Thanks :)
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby bucoops » Mon Dec 05, 2016 3:51 pm

Hi All,

I have one more issue to solve - I have my weekly and monthly GFS tape pools. Both copy a weekly full D2D backup.

Weekly works fine, but for some reason the monthly runs twice - once on the first Sunday of the month as scheduled, but then it runs again the next day (and correctly finds no new files so doesn't do anything) Any idea how I can trace why this is doing this?

Thanks :)
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Re: Slow backup to tape - windows dedupe?

Veeam Logoby Dima P. » Mon Dec 05, 2016 6:52 pm

Do you have all the source restore points in place for the Monthly backup date? GFS job can restart itself if source jobs are running.
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