Hello!

I have strange situation. I`m testing performance of PostgreSQL database at different filesystems (ext2,ex3,jfs) and I cant say that JFS is as much faster as it is said.
My test look`s like that:

Server: 2 x Xeon 2,4GHz 2GB ram 8 x HDD SCSI configured in RAID arrays like that:

Unit UnitType Status %Cmpl Stripe Size(GB) Cache AVerify IgnECC
------------------------------------------------------------------------------
u0    RAID-10   OK             -      64K     467.522   ON     -        -
u6    RAID-1    OK             -      -       298.09    ON     -        -

Port   Status           Unit   Size        Blocks        Serial
---------------------------------------------------------------
p0     OK               u0     233.76 GB   490234752     Y634Y1DE
p1     OK               u0     233.76 GB   490234752     Y636TR9E
p2     OK               u0     233.76 GB   490234752     Y64VZF1E
p3     OK               u0     233.76 GB   490234752     Y64G8HRE
p4     NOT-PRESENT      -      -           -             -
p5     OK               -      233.76 GB   490234752     Y63YMSNE
p6     OK               u6     298.09 GB   625142448     3QF08HFF
p7     OK               u6     298.09 GB   625142448     3QF08HHW


where u6 stores Fedora Core 6 operating system, and u0 stores 3 partitions with ext2, ext3 and jfs filesystem. Postgresql 8.2 engine is intalled at system partition (u6 in raid) and run with data directory at diffrent FS partition for particular test. To test I use pgBench with default database schema, run for 25, 50, 75 users at one time. Every test I run 5 time to take average. Unfortunetly my result shows that ext is fastest, ext3 and jfs are very simillar. I can understand that ext2 without jurnaling is faster than ext3, it is said that jfs is 40 - 60% faster. I cant see the difference. Part of My results: (transaction type | scaling factor | num of clients | tpl | num on transactions | tps including connection time | tps excliding connection time)

EXT2:

TPC-B (sort of),50,75,13,975|975,338.286682,358.855582
TPC-B (sort of),50,75,133,9975|9975,126.777438,127.023687
TPC-B (sort of),50,75,1333,99975|99975,125.612325,125.636193

EXT3:

TPC-B (sort of),50,75,13,975|975,226.139237,244.619009
TPC-B (sort of),50,75,133,9975|9975,88.678922,88.935371
TPC-B (sort of),50,75,1333,99975|99975,79.126892,79.147423

JFS:

TPC-B (sort of),50,75,13,975|975,235.626369,255.863271
TPC-B (sort of),50,75,133,9975|9975,88.408323,88.664584
TPC-B (sort of),50,75,1333,99975|99975,81.003394,81.024297


Can anyone tell me what`s wrong with my test? Or maybe it is normal?

Pawel Gruszczynski

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