Ultrium 448 - taking 9 hours to backup 85GB

[neil robb]

We have a Storageworks 1U rack with two Ultrium 448 drives in it.

One drive is taking 9 hours to backup 85GB, the other takes 4 hours to backup 85GB.

Both drives are indentical in all aspects of hardware, firmware and connection settings.

The slow drive is backing up a DC and the fast drive is backing up a member server.

My theory is that the DC is just plain busy - we run 24/6 as we have both UK and Australasia offices working on both servers; however I thought I'd share the problem here in case there is anything you experts can think of that we've not done.

We have:

1. Updated firmware on both backup drives.
2. Updated firmware on each HDD of the DC.
3. Updated the firmware on the RAID controller.
4. Checked all software settings.

We haven't:

1. Swapped the drives around to see if its a faulty backup drive. This is our next step but we figure as the back is completing 100% is not going to be a hardware issue.

I'd appreciate any advice or help,

Regards,

Neil Robb
IT Co-ordinator
An International Recruitment Company

[Lewis Finch]

Neil, This document may help you. Also, Although block size is not supposed to make a difference for these drives, I have seen cases where changing block size to 64k does help. Try it and let us know.

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=lpg50460

[Maarten ter Bekke]

Hi Neil,

What I usually do to test if either server or tapedrive is the bottleneck, is create a tapedrive filetype to a null-device (either /dev/null (for Unix) or nul (for Windows).
This will prove if the hardware is causing delay or maybe the network. By creating the null-device on the clientsystem itself, you can also exlude networkinfluences.
You do not mention the backup application, but different settings in the application can cause delay as well. For instance Removable Storage Manager is notorious.

Good luck
Maarten