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Ultrium slow down

Chris Wyld
Frequent Advisor

Ultrium slow down

I have an Ultrium 230e connected to an HP ML570G2 via the built in SCSI connection. It has been backing up about 185GB of data using Veritas' Backup Exec for Windows 2000. The backups have been running fine and still are. However, the backup used to take about 3 hours to finish, now it takes between 7 and 8. There has been no additional data, at least not enough to double the length of the backup. The data is stored on a VA7410 running RAID 0+1. Any suggestions?
14 REPLIES
David Ruska
Honored Contributor

Re: Ultrium slow down

Assuming nothing else has changed in the backup specs (i.e. block size, etc), either the data is being sourced at a slower rate (i.e. disk fragmentation), or the the drive is having error rate problems causing it to rewrite blocks. If you can install HP Library & Tape Tools (www.hp.com/support/tapetools), you can run some tests (e.g. the drive performance test) to see if the drive can run at 15MB (native). You can also generate a support ticket, and post it here after writing to a tape, and we can look at the error rate numbers.
The journey IS the reward.
Shaikh Imran
Honored Contributor

Re: Ultrium slow down

Hi,
I have faced the similar problem with the Ultrium 6/60 library and i got it replaced from HP and it worked fine.
Also check for the latest firmware and try
upgrading it first if it is with the latest firmware then i will advise you to do the same as i did.

Regards
I'll sleep when i am dead.
Shaikh Imran
Honored Contributor

Re: Ultrium slow down

Hi,
I forgot to mention in my earlier post that i have changed one drive not all.
And since i was having a library with 6 drives it was easy for me to diagnose and replace the drive.

Regards
I'll sleep when i am dead.
Chris Wyld
Frequent Advisor

Re: Ultrium slow down

David and Shaikh,
Thank you for the information. First, I said I was using a 230e when it is actually a 460e. My apologies.
I updated the firmware on the drive and ran the LTO Acceptance test with no errors. Any other tests I can or should run to verify the drive is operating as it should? Regarding disk fragmentation, is that really an issue if the data being backed up is on a SAN device?
David Ruska
Honored Contributor

Re: Ultrium slow down

The 460e drive is much more demanding as far as host-supplied data rates in order to keep it streaming (i.e. need to provide 60MB/sec with 2-to-1 compressible data).

I suggest running the device performance test in L&TT, and see if the drive streams from there.

Here's a document on tape performance testing/tuning:
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=lpg50460

If you can generate an LTT support ticket after running the acceptance test (while the tape is still loaded), and the post it here (or I can give you an email address to send it to), we can review all the drive error rate and related logs in detail.
The journey IS the reward.
Chris Wyld
Frequent Advisor

Re: Ultrium slow down

I don't see a device performance test. There is a device self test and a device analysis. Are you referring to one of those?
David Ruska
Honored Contributor

Re: Ultrium slow down


Sorry, I should have gave some more details. The Device Performance tests are separate from the device specific tests.

Rather than selecting the "Test" button, click on the "Dev Perf" button on the tool bar.
The journey IS the reward.
Chris Wyld
Frequent Advisor

Re: Ultrium slow down

O.k., I've run the Drive Performance and saved it (I think) to a log file which I will include here. It looks to me like the drive is running woefully slow.
Dave Dewar
Trusted Contributor

Re: Ultrium slow down

Hi Chris,

Doesn't appear to be any wrong with the drive, error rates are fine, no rewrites occurring. The issues you are facing appear to be system related. The support ticket indicated the following additional things which might be of some help to you in debugging the issue.

1. The drive is stream failing, it is moving between idle and write mode which means you are sending data to it at less than 10MB/sec. The performance log is stating 11Mb/s but this is after compression.
2. Your scsi connection to the drive is configured in narrow mode. Please check that nothing has altered with respect to your onboard scsi controller and cabling.

There is also a sys perf set of tests in LTT, button next to dev perf tests that allow you to see how fast you can get data from your disks to memory to see if you have a disk IO bottleneck. Also, what results were you getting when you ran the drive perf tests? These transfer data from memory to drive and knows this info would allow us to help pinpoint the issue,

The guide Dave Ruska posted above is an excellent trouble shooting guide to performance that makes use of the LTT tests and our other standalone tools to help identify the issue

Cheers,

Dave Dewar
Chris Wyld
Frequent Advisor

Re: Ultrium slow down

Dave,
I'm getting a transfer rate of 9MB/sec. on both the device performance and the system performance. Any suggestion on where I should start looking for a bottleneck? As I stated in my original message, the backups ran fine for over 3 months and then one day, the transfer rate went from 1400MB/min. to 540MB/min.
Dave Dewar
Trusted Contributor

Re: Ultrium slow down

Chris,

I know Dave Ruska was planning to contact you about this and the fact that your scsi connection appears to be configured in narrow mode.

Let me know if you still have an issue and we can go from there.

Cheers,

Dave Dewar
Chris Wyld
Frequent Advisor

Re: Ultrium slow down

Yes I still have the same problem. I have not configured the SCSI card so I'm not sure how to change it from narrow to wide.
Dave Dewar
Trusted Contributor

Re: Ultrium slow down

Hi Chris,

I am wondering whether something has changed in your system that might explain why you are now operating in narrow scsi mode and explain hence explain the change in performance.

Can you check to see if you get any messages during server bootup from the scsi HBA bios?

Typically, you get some info about drives detected and modes configured during server bootup from SCSI HBA's with bios installed.

It might be a good idea to check your cabling as well if you have not already done so.

Cheers,

Dave Dewar
Zig_1
Occasional Advisor

Re: Ultrium slow down

sounds like someone set you up the bomb