Messages in this thread |  | | | Subject | Re: Filesystem benchmarks: ext2 vs ext3 vs jfs vs minix | | From | Andi Kleen <> | | Date | 27 Mar 2002 15:09:19 +0100 |
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Matthew Kirkwood <matthew@hairy.beasts.org> writes:
> PostgreSQL > tuning? single ir mx-ir oltp mixed-oltp > (sec) (tps) (sec) (tps) (sec) > ext2 dd 1304.72 66.64 214.25 188.50 230.55 > dn 1288.31 65.93 209.57 234.08 213.75 > bn 1283.50 77.90 1867.71 192.43 226.77 > > ext3 dd 1303.84 66.87 212.49 66.06 361.04 > dn 1288.03 64.62 209.27 111.41 278.54 > bn 1285.32 65.98 1996.41 90.05 307.79
This is ext3 with ordered data?
> minix dd 1305.26 67.38 207.74 193.90 228.81 > dn 1331.27 67.14 210.07 223.70 214.33 > bn 1299.24 89.58 1988.31 231.17 231.17
Wow minix is faster than ext2 @) That certainly looks strange.
Any chance to test XFS too?
> 3. The journalled filesystems do have measurable overhead > for this workload.
Normally (non data journaling, noatime) journaling fs shouldn't have any overhead for database load, because database files should be preallocated and the database should do direct IO in/out the preallocated buffers with the FS never doing any metadata writes, except for occassional inode updates for mtime depending on what sync mode that DB uses (hmm, I guess a nomtime or verylazymtime or alwaysasyncmtime mount option could be helpful for that)
That's the theory, but doesn't seem to be the case in your test. I guess your test is not very realistic then.
> 2. What does jfs do in the way of data journalling? Is it > "ordered" or "writeback", in ext3-speak? (I assume > fully journalled data would give much worse performance.)
Kind of ordered I believe.
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