HP StorageWorks 1/8 Autoloader

[Serverteam-nhs]

I am hoping you can help with very poor backup speeds.

We have

NAS 2000s
HP StorageWorks 1/8 Autoloader
Ultrium LTO 2

BrightStor Arcserve Version 11
McAfee Version 7

Smart Array 5i Controller in Embedded Slot
with OS and Tape Device
Smart Array 6400 Controller with 1.5TB of data (ADG)

The backup is taking about 14 hours to backup 500GB of data. If your unlucky enough to be at work when the backup starts you see the drive writing then 'drive stopped' for about 30 - 60 seconds before 5 seconds of 'drive writing' and then 'stopped' etc, etc.

Any help appreciated?
Thanks

[Steven Clementi]

Get yourself a regular SCSI Adaptor for the Autoloader. Though it may work on the Smart Array, your performance will be bad, really bad. The Smart Array IS mainly for DISK, not TAPE.


Steven

[Marino Meloni_1]

this doc can explain you how to tune your system:

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

marino

[Serverteam-nhs]

Hello

We have installed a

Ultra320 SCSI HBA G2 374654-B21

and still no improvement.

I am I missing something?
Thanks

[raadek]

1) Arcserve is probably not the fastest product out there - I've heard already about similar problems when backing up with this software

2) Is read cache on your SA6400 switched on?

3) Are your data disks SCSI or SATA?

4) In both cases (but especially for SATA) I would recommend migrating from ADG to RAID 5 + hot-spare. ADG has massive performance overhead for writes, but I think for reads it is still slower than any other RAID level.

Rgds.

[Benoît]

LTO2 will backup at 30 MB/s compressed (108 GB/h), if given a feedspeed of 3:1 so 90 MB/s
So at full speed you should backup 500 GB in about 5 hours.

I'm sure you don't get 90 MB/s out of your RAID ADG configuration.
This means the drive can't write at full speed and needs to stop, rewind, restart ... all the time, waiting for is buffer cache to be full.
ATS (Adaptive Tape Speed) on LTO drive can reduce this effect, slow down is writing speed to adapt it depending on the buffer cache and write at 11 MB/s

Do you maths : at 11 MB/s (you need 39,6 GB/s) you need more than 12,6 hours to backup your 500 GB.
On that, add the time to change tapes (about 7% time of the backup), and you get 13,5 hours to do it.

This is pure theory and this is the worst case but this might be close to reality, especially if you also think off your anti-virus software which might slow down backups ...

So you need to find a way to speed up your primary storage.
RAID5 + spare is the first improvement.

How many drives do you have?

[Benoît]

You can also try diags and bench with L&TT.

[Benoît]

As L&TT tests your tape drive perf, you can use HPReadData to test your primary storage perf.