ext3 performance with external log

[Boris Erl]

Hi,

I have strange benchmarking results: ext3 with internal log performs 3 times
faster then with external log.

Linux ES 3.0 (kernel 2.4.21-9.0.1ESsmp), Dell PE 2600, 2 CPU 2.4GHz, 6GB
RAM, Adaptec Ultra 160 SCSI 29160 controller

External hardware 9-disk RAID 0; 512MB write-back controller cache; U160

Benchmark: SpecSFS v 3.0
Mount options: data=journal,sync,

Export options: sync,


With ext3 FS on external 9-disk RAID 0
     internal log  ~  3000 NFS Ops/sec
     external log on a second partition on the same RAID 0 ~ 1000 Ops/sec
     external log on a dedicated HD (without write-back cache) or NVRAM card
~ 1000 Ops/sec


Will appreciate any ideas.

Boris Erlikhman