Hi Radek,
let me explain: it is neverending story (best word is war) between us - system guys - and programmer. I wolud like to say, that we monitor and analyze netapp (with help of netapp support) about month or two. Analysis shows, that there is no problem (with performance, latency or other). But the problem is, that before netapp we used IBM DS8100 and batch processing were slightly faster. It's normal that when you change the storage you expect better processing time. I also know and take note, that there is many other factors which affect the performance (maybe is who, who doesn't want to hear)- the database is greater, in the last time DS has been unloaded and it was working only for this server and in the end DS use 300GB 15Krpm DDM, netapp has 600 GB 15Krpm DDM.
About spining - i don't know and i don't suspect, that ther will be the problem - i use aggregat with 36 modules, i'm not sure, but i think that in DS i have pool with 30 or 32 modules.
About FC - we use 2 x 4 FC connections from netapp (2 fabric with 4 cable in each, 8 Gbps) and 2 fc connection from server (4 Gbps in each fabric). I monitored and analyzed also SAN (with special tools) and there is no bottleneck.
So briefly: there is a "problem" only with this server (we have another 5 same servers, with same os for db) and only with batch processing. And this is feeling of programers (ok - we can measure the time of jobs). So my job is to convince them, that netapp work fine.
Therefore, i investigate in the direction of "fine tuning" between server (RHEL) and netapp. If maybe is some hidden settings on RHEL, which would help to improve the performance.
Best regards,
Robi