Hi all -
Thanks to the work of many on this mailing list, I've been able to install SID (w/ kernel 2.6.32-5) on my SS4000-E NAS.
Much to my surprise, the performance of the unit is pretty much identical to how it was running the proprietary Falconstor implementation.
hdparm -tT /dev/sda reads :
Timing cached reads: 128 MB in 2.00 seconds = 63.93 MB/sec
Timing buffered disk reads: 114 MB in 3.04 seconds = 37.44 MB/sec
The results from hdparm are static across all 4 drives.
Needless to say -- these numbers are atrocious. Max throughput by any means (NFS, FTP, etc.) is about 5MB/sec on writes to the NAS, and 8-9MB/sec on reads from it.
I did come across an earlier post from "Andrushka" that stated 2.6.32 has DMA enabled for "this platform". >From everything I have read, there is no DMA to enable/disable for SATA, but my knowledge is extremely limited in this arena. He does claim that an alternative linux distro installed on the box got 12MB/sec out of the unit.
I'm wondering if anyone has figured out why the performance of this unit is so overwhelmingly bad, or if anyone has suggestions on how to go about diagnosing the cause?