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Ultrium 448 internal sas tape drive really slow

 
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New Member

Ultrium 448 internal sas tape drive really slow

Ultrium 448 internal sas is really slow in reading and consequently writing files.

Dev Perf in L&TT is OK and i think there is a bottleneck in reading.

Attached the support ticket

3 REPLIES 3
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Trusted Contributor

Re: Ultrium 448 internal sas tape drive really slow

Fabio you have lots of Test Unit Ready (TUR)

http://support.microsoft.com/kb/842411/en

Pablo Alvarado Siles
Pablo Alv Siles
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New Member

Re: Ultrium 448 internal sas tape drive really slow

I've disabled TUR on Device but nothing have changed.

With previous DAT 72 with USB connection all worked properly.

Any other idea?
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Respected Contributor

Re: Ultrium 448 internal sas tape drive really slow

Is the LTO drive slower than the DAT drive was?

The tape drive doesn't actually read files from your disk; the backup application asks the file system to provide the files, and then writes them to tape. So if reads from disk are slow, it's probably the file system. Have you used L&TT to benchmark the disk you're trying to back up? How does L&TT read performance compare to the backup speeds you're seeing?

If the problem is your read speed, you can try defragmenting your disk, moving to faster disk (hardware RAID, particularly RAID 1+0 instead of single disks or SW RAID), or sending multiple streams of data to the tape drive at once. Or, the biggest improvement is likely to be changing to an image backup (where the disk is read sequentially, block-by-block, instead of randomly, file-by-file) -- but restore from a sequential backup will typically take longer than a restore from a file backup.

Other considerations -- I have seen backup job performance drop as much as 50% when the backup application is used to do either compression or encryption -- make sure you're using the tape drive for compression, and evaluate your encryption strategy (consider using LTO-4 and its HW encryption) if applicable.

All the above assumes you're doing a local backup -- there are some other considerations if you are doing a backup over the network.
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