You can go into the configuration for the relevant media pool and restrict it to only one drive. I'm not too sure if that will have any impact on your problem though...
Hello Experts, is there any way how can i force a ndmp restore to use only 1 of 2 tape drives? the problem is as follows
networker 7.2.2 on windows celera client backed up via ndmp 2 tape drives available on the server (LTO3) data resides on 2 tapes restore of 20GB running extremely slow (1600 MB/day) restore job reads both tapes at the same time (and what is worse at the same speed)
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I assume DAR is enabled? Also, by chance do you have non-NDMP and NDMP data on same tape?...just checking possibilities...
2.7TB on LTO3? Wow... not sure what you backup there, but those files must compress really good. Nevertheless, I do not think compression can slow it down that much.
In our installation earlier, we had mixed data on tape and the restore speed was slow. After separating the two, the restore speed is much faster. I think there's a doc listing the problems associated with mixing non-NDMP/NDMP on same tape. Take a look and see if it applies to you...
i tried to restore 28 KB in 2 files and after an hour nothing restored so i stopped it.
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Maybe the tape drive was moving back/forth a lot, trying to find file/file-marks.? You may be able to see it from nsrwatch.
To confirm that mixing non-NDMP/NDMP on same tape is indeed the issue, you may try this. Take a fresh backup on a NDMP tape (with DAR enabled). Then try a test recovery and see the speed?
DAR is best used for recovering a few files from a large save set. When trying to recover hundreds of files the recover rate is very slow.
In order to use nwrecover for recovering many files you must take out the line "DIRECT=y" in client setup. The restore will parse the whole saveset. Once finished, remember to put DIRECT=y back again.
What is says above is that positioning using DAR for many files will probably take more time then reading whole savesets and dumping only what is selected. In your case you said you had only two files so I doubt that is the case.
ble1
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May 20th, 2009 07:00
That's really slow...
PeterBen
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May 20th, 2009 08:00
DavidHampson
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May 20th, 2009 10:00
satishs
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May 20th, 2009 11:00
is there any way how can i force a ndmp restore to
use only 1 of 2 tape drives?
the problem is as follows
networker 7.2.2 on windows
celera client backed up via ndmp
2 tape drives available on the server (LTO3)
data resides on 2 tapes
restore of 20GB running extremely slow (1600 MB/day)
restore job reads both tapes at the same time (and
what is worse at the same speed)
=========
I assume DAR is enabled? Also, by chance do you have non-NDMP and NDMP data on same tape?...just checking possibilities...
ble1
4 Operator
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May 20th, 2009 11:00
PeterBen
120 Posts
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May 20th, 2009 23:00
UPDATE=y
DIRECT=y
UTF8=y
but the data can be mixed on the tape.
satishs
50 Posts
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May 22nd, 2009 05:00
UPDATE=y
DIRECT=y
UTF8=y
but the data can be mixed on the tape.
-------------------
In our installation earlier, we had mixed data on tape and the restore speed was slow. After separating the two, the restore speed is much faster. I think there's a doc listing the problems associated with mixing non-NDMP/NDMP on same tape. Take a look and see if it applies to you...
PeterBen
120 Posts
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May 26th, 2009 23:00
the restore is 0.05 MB/s OMG!
satishs
50 Posts
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May 27th, 2009 09:00
document name?
the restore is 0.05 MB/s OMG!
https://solutions.emc.com/emcsolutionview.asp?id=esg61005
Is the speed slow regardless of size/number of files to be restored?
PeterBen
120 Posts
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May 28th, 2009 06:00
satishs
50 Posts
0
May 28th, 2009 07:00
nothing restored so i stopped it.
-----------
Maybe the tape drive was moving back/forth a lot, trying to find file/file-marks.? You may be able to see it from nsrwatch.
To confirm that mixing non-NDMP/NDMP on same tape is indeed the issue, you may try this. Take a fresh backup on a NDMP tape (with DAR enabled). Then try a test recovery and see the speed?
PeterBen
120 Posts
0
June 5th, 2009 05:00
PeterBen
120 Posts
0
June 5th, 2009 07:00
DAR is best used for recovering a few files from a large save set.
When trying to
recover hundreds of files the recover rate is very slow.
In order to use nwrecover for recovering many files you must take
out the line
"DIRECT=y" in client setup. The restore will parse the whole
saveset. Once finished,
remember to put DIRECT=y back again.
can it be?
ble1
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June 6th, 2009 02:00
PeterBen
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November 5th, 2009 05:00