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Backup to tape and backup to disk (no duplicate) possible?

Created: 24 Jul 2013 • Updated: 24 Jul 2013 | 8 comments


For backing up a large server (6TB) with a lot of files (4 million+) in a lot of folders (400.000+) I am running out of time for creating a backup to disk and a backup to tape before the tapes are taken offsite on Mondays.

I have optimized everything I can on the dedupe side and also on the tapedrive side so the performance I have now is what it is.

One alternative is to stop backing up this machine to dedupe storage but that kind of defeats the purpose of what we want to achieve for this machine (apart from the fact that we'll run into space issues).

So I was thinking:

What if I create separate jobs for this machine:
- 1 job is straight backup to tape to avoid the rehydration lag from dedupe
- 1 job is straight backup to dedupe storage

And then I first run the backup to tape so that it can be taken offsite on Mondays and after that I run the backup to disk so we have fast restores and fast recovery in case of a server failure

Is this possible? Or will those two jobs interfere with each other?

Thanks for your advice,


Operating Systems:

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Jaydeep S's picture

- 1 job is straight backup to tape to avoid the rehydration lag from dedupe

- 1 job is straight backup to dedupe storage

This should work good as long as the jobs are not running at the same time. Further, I would suggest you to break the job to dedup even more. Create 2 or 3 smaller jobs for seperate resources of that Server like lets say 1 job for C: and System State, the other for one data drive and so on. Once you have these jobs, you might want to run them simultaniously to the dedup device. Yes this would demand a lot of bandwidth, but it can be done.

pkh's picture

Running jobs simultaneously may not save time because there will be resource contention, especially for a resource-intensive operation like dedup.

Jaydeep S's picture

I agree with what you say, but looking at the time window that he has, it could be worth a try as long as he is not backing up partial resources simultaneously, example - part of C drive in 1 job and the rest in 2nd job.

MartijnL's picture

I am running multiple jobs to dedupe anyway so I will try to split it up and see if that gives better results. Main thing is that I don't run into issues with having two full backups on the same dataset.

Now I can start doing some speed tests of the backup to tape to see what kind of speed I get.

Thanks for your input.

pkh's picture

The two jobs would not interfere with each other if they are both full backups.

Kunal.Mudliyar's picture

You have 4 days /96 hours to get this 6 TB backup completed

If you see you past history see how the tape backups ran

if they run 1000 -1200 Mb/min you can finish your bakcup in time.

if the tape gave 2000-2200 MB/min then in 2 days they will finish.

If they complete in 2 days you can use other days to duplicate them to disk or deduplication folder.

If you run both the jobs i doubt you will be able to meet your target.

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MartijnL's picture

Actually I have about 64 hours because the backup starts Friday late afternoon and needs to be finished around 8am on Monday. Currently this is:

  • 6TB to disk over dedicated Gbit connection with server-side dedupe (client side does not work because of incompatible Linux version)
  • 6TB duplicate to tape
  • Verify of the tape backup.

The disk backup has a separate verify job outside of the backup window.

This means that I need to achieve an average transfer rate of 4,8GB/min :)

Kunal.Mudliyar's picture

Theoretically but not practically

1Gbps nic can trasfer at 7500 MB/min

and LTO 6 tape drive can transfer the data at 9000 MB/min

Never seen it happening though ,

Even you if consider 50 % of what you can get  practically it looks like an impossible task to backup duplicate and verify by monday if you start on friday

Consider either one of them :)

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