Peter,
Thanks for your reply. Write buffer coalescing is enabled in the 2.6.32 tree as Arnaud's patch is included. I also ran Peter Teichmann's test program -- all the numbers match up to your post. I am ready to chalk this up to bad hardware and give up on this completely. Having a NAS with 4x SATA 3G drives and two 1GB NICs bottlenecked at 5MB/second is a bad joke from Intel. -Danny ----- Original Message ----- From: "Peter Horton" <z...@colonel-panic.org> To: "danny rodriguez" <danny.rodrig...@comcast.net> Sent: Thursday, May 13, 2010 5:41:24 AM GMT -05:00 US/Canada Eastern Subject: Re: SS4000-E (Lack of) Performance On 13/05/2010 00:55, danny.rodrig...@comcast.net wrote: > > 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 : > /dev/sda: > 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. > > (post is here: > http://us.generation-nt.com/ss4000e-iop-dma-help-170355901.html ) > > > 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? > Not sure it's related but there's a thread about memory performance on the 80129 here http://marc.info/?t=120446234500001&r=1&w=2. I gave up on my N2100 NAS 'cos it was soooo slow. P.
