Hi, I did some tests on a Sun Fire x4540 with an external J4500 array (connected via two HBA ports). I.e. there are 96 disks in total configured as seven 12-disk raidz2 vdevs (plus system, spares, unused disks) providing a ~ 63 TB pool with fletcher4 checksums. The system was recently equipped with a Sun Flash Accelerator F20 with 4 FMod modules to be used as log devices (ZIL). I was using the latest snv_134 software release.
Here are some first performance numbers for the extraction of an uncompressed 50 MB tarball on a Linux (CentOS 5.4 x86_64) NFS-client which mounted the test filesystem (no compression or dedup) via NFSv3 (rsize=wsize=32k,sync,tcp,hard). standard ZIL: 7m40s (ZFS default) 1x SSD ZIL: 4m07s (Flash Accelerator F20) 2x SSD ZIL: 2m42s (Flash Accelerator F20) 2x SSD mirrored ZIL: 3m59s (Flash Accelerator F20) 3x SSD ZIL: 2m47s (Flash Accelerator F20) 4x SSD ZIL: 2m57s (Flash Accelerator F20) disabled ZIL: 0m15s (local extraction 0m0.269s) I was not so much interested in the absolute numbers but rather in the relative performance differences between the standard ZIL, the SSD ZIL and the disabled ZIL cases. Any opinions on the results? I wish the SSD ZIL performance was closer to the disabled ZIL case than it is right now. ATM I tend to use two F20 FMods for the log and the two other FMods as L2ARC cache devices (although the system has lots of system memory i.e. the L2ARC is not really necessary). But the speedup of disabling the ZIL altogether is appealing (and would probably be acceptable in this environment). -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
