Slow read performance from a SA6402 in a ML370G3

[Mike Anton]

Hello all

I indavertantly posted this in the linux forum so here's my second attempt.....

We have a new ML370G3 running Win2k03 as our data server. There are five 72Gb u320 disks setup as one physical raid5 array.

There's about 40Gb of company and user data, most of which is small files, including user profiles.

The backup onto a SDLT2 is pretty slow and I've used HP's PAT tool to see what throughput we are getting. Sequential reads are about 80Mb/sec but 'full' are around the 5Mb/sec mark.

I've got a new card to try but I have a feeling that the sector / cluster / stripe sizes are too big for the files and thus we can't run at full capacity.

Apologies for the long thread but has anyone any ideas on what settings I can tweak?

Thanks

[Rune J. Winje]

HW or SW RAID? HW RAID is vastly superior.

Also the system-disk with the OS/paging file should be on a physically a different disk (and RAID set) than the disk with data.

If HW RAID check that caching is enabled (but also then it is very recommended to have battery-backup on the RAID card and also UPS for the server).

How small files? If they are very small (<2KB) then they may be saved as directly inside the MFT (Master File Table) and the MFT could then easily be fragmented => poor performance. To verify do a Disk Defragmenter > Analyze > View Report and see what it reports for the MFT.


Cheers,
Rune

[Mike Anton]

Hi Rune

HW raid (of course) :-)

Card has 192Mb of enabled cache and f/w 2.26B, which is current. I swapped the card out this morning and performance is pretty much the same so think this is a file sizing issue.

Disk Keeper crashes when I try to look at the report so I'm not sure what state the MFT is currently in.

Do you know of a tool that can give you detailed information on files you have on a drive?

Regards

Mike