I saw a definite improvement by turning off NCQ and setting StorSave to 'Balanced.' Are these 1.5GB/Sec or 3.0GB/Sec SATA drives? During my testing I changed from non-interleaved memory and 1.5GB to interleaved and 3.0GB. Made a big difference in bonnie++ results. Unfortunately, I can't say which was more important.
If you have the patience, read through my recent (but lengthy) thread on the 3Ware 9550 titled "Calling All FS Fanatics." There's a lot of good info from many helpful people. I've only gotten full performance using JFS or XFS.
Kirk Bocek
Bowie Bailey wrote:
I have two identical servers. The only difference is that the first one has Maxtor 250G drives and the second one has Seagate 320G drives.
OS: CentOS-4.4 (fully patched) CPU: dual Opteron 280 Memory: 16GB Raid card: 3ware 9550Sx-8LP Raid volume: 4-disk Raid 5 with NCQ and Write Cache enabled
On the first server I have decent performance. Nothing spectacular, but good enough. The second one has about 1/3 the write speed. I can't find any difference between the systems. Both of them have the same stripe size, both have ext3 filesystems, both have write caching and NCQ turned on. I have already increased the read ahead setting to 16384 on both servers.
I ran the tests like this:
# sync; bonnie++ -d /iotest -s 50g -n 0 -b -f (I have removed some extra information from the reports for brevity)
And here are the results for the two servers:
------Output------- --Input-- --Block-- -Rewrite- --Block-- --Seeks--Machine Size K/sec %CP K/sec %CP K/sec %CP /sec %CP First 50G 62893 25 46763 12 160672 19 120.6 1 Second 50G 18835 7 44025 12 194719 24 122.8 1
As you can see, the write performance of the second server is terrible. Anyone have any suggestions of what I can look for? I keep thinking there must be something I tweaked on the first server that I forgot about for the second one, but so far I haven't been able to find it.
Any suggestions appreciated!