Greg, Josh, Something I found out while doing this - lvm (and lvm2) slows the block stream down dramatically. At first I was using it for convenience sake to implement partitions on top of the md devices, but I found I was stuck at about 700 MB/s. Removing lvm2 from the picture allowed me to get within chucking distance of 2GB/s.
When we first started working with Solaris ZFS, we were getting about 400-600 MB/s, and after working with the Solaris Engineering team we now get rates approaching 2GB/s. The updates needed to Solaris are part of the Solaris 10 U3 available in October (and already in Solaris Express, aka Solaris 11). - Luke On 9/15/06 5:43 AM, "Spiegelberg, Greg" <[EMAIL PROTECTED]> wrote: > That's an all PCI-X box which makes sense. There are 6 SATA controllers > in that little beastie also. You can always count on Sun to provide > over engineered boxes. > > > >> -----Original Message----- >> From: [EMAIL PROTECTED] >> [mailto:[EMAIL PROTECTED] On Behalf Of >> Joshua D. Drake >> Sent: Friday, September 15, 2006 12:01 AM >> To: Luke Lonergan >> Cc: Craig A. James; pgsql-performance@postgresql.org >> Subject: Re: [PERFORM] RAID 0 not as fast as expected >> >> Luke Lonergan wrote: >>> Josh, >>> >>> On 9/14/06 8:47 PM, "Joshua D. Drake" <[EMAIL PROTECTED]> wrote: >>> >>>>> I've obtained 1,950 MB/s using Linux software RAID on SATA drives. >>>> With what? :) >>> >>> Sun X4500 (aka Thumper) running stock RedHat 4.3 (actually >> CentOS 4.3) >>> with XFS and the linux md driver without lvm. Here is a >> summary of the results: >>> >> >> >> Good god! >> >>> >>> Read Test >>> RAID Level Max Readahead (KB) RAID Chunksize Max Readahead >> on Disks >>> (KB) Max Time (s) Read Bandwidth (MB/s) 0 65536 64 256 16.689 >>> 1,917.43 0 4096 64 256 21.269 1,504.54 0 65536 256 256 17.967 >>> 1,781.04 0 2816 256 256 18.835 1,698.96 0 65536 1024 256 18.538 >>> 1,726.18 0 65536 64 512 18.295 1,749.11 0 65536 64 256 18.931 >>> 1,690.35 0 65536 64 256 18.873 1,695.54 0 64768 64 256 18.545 >>> 1,725.53 0 131172 64 256 18.548 1,725.25 0 131172 64 >> 65536 19.046 >>> 1,680.14 0 131172 64 524288 18.125 1,765.52 0 131172 64 1048576 >>> 18.701 1,711.14 >>> 5 2560 64 256 39.933 801.34 >>> 5 16777216 64 256 37.76 847.46 >>> 5 524288 64 256 53.497 598.16 >>> 5 65536 32 256 38.472 831.77 >>> 5 65536 32 256 38.004 842.02 >>> 5 65536 32 256 37.884 844.68 >>> 5 2560 16 256 41.39 773.13 >>> 5 65536 16 256 48.902 654.37 >>> 10 65536 64 256 83.256 384.36 >>> 1+0 65536 64 256 19.394 1,649.99 >>> 1+0 65536 64 256 19.047 1,680.05 >>> 1+0 65536 64 256 19.195 1,667.10 >>> 1+0 65536 64 256 18.806 1,701.58 >>> 1+0 65536 64 256 18.848 1,697.79 >>> 1+0 65536 64 256 18.371 1,741.88 >>> 1+0 65536 64 256 21.446 1,492.12 >>> 1+0 65536 64 256 20.254 1,579.93 >>> >>> >> >> >> -- >> >> === The PostgreSQL Company: Command Prompt, Inc. === >> Sales/Support: +1.503.667.4564 || 24x7/Emergency: +1.800.492.2240 >> Providing the most comprehensive PostgreSQL solutions since 1997 >> http://www.commandprompt.com/ >> >> >> >> ---------------------------(end of >> broadcast)--------------------------- >> TIP 2: Don't 'kill -9' the postmaster >> > ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org
