Re: Slow Soft-RAID 5 performance

2007-07-19 Thread Rui Santos
koan wrote: > Are you sure about that chunk size? In you initial posting you show > /proc/mdstat reporting: > > "md2 : active raid5 sdc3[2] sda3[0] sdb3[1] > 780083968 blocks level 5, 128k chunk, algorithm 2 [3/3] [UUU]" > > Which would seem to state a 128K chunk, and thus with a 4k block size

Re: Slow Soft-RAID 5 performance

2007-07-18 Thread koan
Are you sure about that chunk size? In you initial posting you show /proc/mdstat reporting: "md2 : active raid5 sdc3[2] sda3[0] sdb3[1] 780083968 blocks level 5, 128k chunk, algorithm 2 [3/3] [UUU]" Which would seem to state a 128K chunk, and thus with a 4k block size you would need a strid

Re: Slow Soft-RAID 5 performance

2007-07-18 Thread Rui Santos
J.A. Magallón wrote: > On Wed, 18 Jul 2007 10:56:11 +0100, Rui Santos <[EMAIL PROTECTED]> wrote: > > >> Hi, >> >> I'm getting a strange slow performance behavior on a recently installed >> Server. Here are the details: >> >> > ... > >> I can get a write throughput of 60 MB/sec on each

Re: Slow Soft-RAID 5 performance

2007-07-18 Thread Rui Santos
koan wrote: > How did you create the ext3 filesystem? The chunk_size is at 256KB, ext3 block size is 4k. I believe the correct option that should be passed trough to --stride is 64. Am I correct ? I've also tested ( after sending my first report ) with xfs. I've also increases readahead to 65535

Re: Slow Soft-RAID 5 performance

2007-07-18 Thread J.A. Magallón
On Wed, 18 Jul 2007 10:56:11 +0100, Rui Santos <[EMAIL PROTECTED]> wrote: > Hi, > > I'm getting a strange slow performance behavior on a recently installed > Server. Here are the details: > ... > > I can get a write throughput of 60 MB/sec on each HD by issuing the > command 'time `dd if=/dev/z

RE: Slow Soft-RAID 5 performance

2007-07-18 Thread koan
How did you create the ext3 filesystem? Did you use the appropriate --stride option as noted here: http://tldp.org/HOWTO/Software-RAID-HOWTO-5.html (#5.11) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info a

Re: Slow Soft-RAID 5 performance

2007-07-18 Thread Justin Piszcz
On Wed, 18 Jul 2007, Rui Santos wrote: Hi, I'm getting a strange slow performance behavior on a recently installed Server. Here are the details: Server: Asus AS-TS500-E4A Board: Asus DSBV-D ( http://uk.asus.com/products.aspx?l1=9&l2=39&l3=299&l4=0&model=1210&modelmenu=2 ) Hard Drives: 3x Sea

Slow Soft-RAID 5 performance

2007-07-18 Thread Rui Santos
Hi, I'm getting a strange slow performance behavior on a recently installed Server. Here are the details: Server: Asus AS-TS500-E4A Board: Asus DSBV-D ( http://uk.asus.com/products.aspx?l1=9&l2=39&l3=299&l4=0&model=1210&modelmenu=2 ) Hard Drives: 3x Seagate ST3400620AS ( http://www.seagate.com/ww