performance with L3000

[Pat Novak_1]

We have an environent where an L3000 is being used as a veritas Media server,and a strange occurance is going on when we access more than 4 LTO drives, disk i/o performance goes down greatly. The L3000 has 10 slots, but apparently 2 of them are shared-bus, so they only use the 8 non-shared ones. 4 are for the Tape HBAs (remember they're attaching 2 SCSI LTO drives to a single fibre HBA using a router), and 4 are for disk attachment. As they scale beyond 4 tape drives, performance of the DISK degrades.
My question is is this a L3000 architecture question or where do I go from here

[harry d brown jr]

Actually, they all share the same bus. BUT, a few slots are just PCI slots, while the others are turbo PCI.

I believe it's a veritas and a hardware design issue, but that's just my opinion.

Also, make sure you have your machine up to date in patches.

live free or die
harry

[Eugeny Brychkov]

Pat,
do you have HP Surestore Galactica LTO libraries (2/20, 4/40, etc)? It's hard to understand your configuration and hardware used (FC router?). Anyway first I would like you to check are:
- LTO firmware. Install HP Library and Tape Tools or use STM;
- make sure host provides at least 15MB/s to each drive. If value is less, LTO drive will feel not good and live not too long
- check disks' firmware (or disk array if applicable)
Eugeny

[rick jones]

There are something like 4 or 5 single-slot (aka non-shared) PCI slots in an L Class system. I believe they are the top N slots in the box. These would correspond to the slots labled "twin turbo"

I am confident that there are not 8 non-shared bus PCI slots in an L Class.

The remaining slots are on shared PCI busses. These may be labled "turbo"

One way to see if a slot is on a shared bus is to look at the hardware paths.