grigi77 Absent Member.
Absent Member.
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very slow restore

Hello gurus,

I would like to ask you question about restore. We tried to do an restore of files from fileserver (cca 300 GB). When we start restore, speed is pretty good, almost 20GB in 20 minutes, but then it almost stopped and restore is very very slow.

I did a list of restored files, so then I tried to restore just those files which made this restore slow. I choosed 5 small files with capacity 1 MB together and tried to restore them. It tooks more then 20 minutes, which is not acceptable. This files have very deep directory structure (more then 16 directories) and names of directories and files are sometime too long. Could this be a problem of slow restore? If I do a restore of files, which are not so deep in directory structure, it is good.

On the other hand, I tried those 5 files restore also on different server (backup server) and it was restored in the second. I don't think that problem is in network between backup server and restored client, because, as I wrote, other files are restored with good speed.

Thank you.
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8 Replies
higo Contributor.
Contributor.

Re: very slow restore

Hi,

If you are sure that it's not a network problem, verify that the Autonegociation of lan card (client) is set to ON

I hope this help you

Good luck
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grigi77 Absent Member.
Absent Member.

Re: very slow restore

Hello,
yes, I was thinking about this and we can try it, but I am not sure, that this can help, because this problem is still with the same files in few direcotries and those are files which are very deep in directory hierarchy. Each time I want to restore them, its very slow. If I choose different files, its ok.
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Marlou Everson Absent Member.
Absent Member.

Re: very slow restore

For comparison, what happens if you restored the 5 small files to the same server but to a different location that's not 16 directories deep?

Marlou
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grigi77 Absent Member.
Absent Member.

Re: very slow restore

Hello,
I made some tests and I found out, that:

1. This problem appears just when I restore those files on 2 nodes. If I restore it to different nodes, it is restore quite fast.

2. This happens just when I set "Restore time attributes". I was monitoring restore proces and I found out, that file is restored very fast, but restore of time attributes took sometimes 3-4 minutes on this files.

If I turn off "Restore time attributes", restore takes 5 hours and 20 minutes. If it is set, it takes almost 40 hours.

Any idea?

Thank you.
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grigi77 Absent Member.
Absent Member.

Re: very slow restore

Hi,
I made another test. It is still valid what I wrote above, if "Restore time attributes" is turned off, it is ok. If it is on, it is very slow. Also there is another think, which has influence on this. It is path lenght. If I do a restore to directory E:\Backup_tests\(long path)..restore of one file takes almost 12 minutes. If I do a restore to E:\Test\(long path)..it takes almost 4 minutes and as I wrote, if I turn off "Restore Time Attributes", it is within second.
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grigi77 Absent Member.
Absent Member.

Re: very slow restore

Hello,

I found out, that this problem appears only when directory path lenght is more than 255 characters. If it is 255 and less, it works ok.
What is strange, that we have other servers, where this work also if there is more than 255 characters. This problem is just on 2 MS cluster nodes.

Any ideas?

Thanks

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Trusted Contributor.. VIVEKKV1 Trusted Contributor..
Trusted Contributor..

Re: very slow restore

Dear all
I am also having here a restore slowness. We are using hpdp 10.00 in hp unix 11.31 along with msl 6480 tapelibrary with LTO 7 tapes. For a size of 1 TB data, backup is completing in 45 minutes. If i restore the same backup into the original location its taking 135 minutes. Can anybody suggest is there anything to do here? Or is this result is ok?
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Knowledge Partner Knowledge Partner
Knowledge Partner

Re: very slow restore

Hello VIVEKKV1,

This depends on multiple factors. Could be the destination disk subsystem or file system, network or even virus scanners.

If the backup media has been created with a concurrency higher than 1 then longer restores times are expected. In this case the tape drive has to read more data then it has actually to restore since multiple data streams have been written in the sequential data stream. You can see the amount of data read in the Monitor context on the drive reading the source media and use those numbers. Maybe you want to decrease the concurrency on the backup drive, perform backup and restore tests again.

Regards,
Sebastian Koehler

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