Reducing ZFS blocksize to improve Cyrus write performance ?

[Pascal Gienger]

Am 09.08.10 19:46, schrieb Vincent Fox:
> * Turn off ZFS cache flushing
> set zfs:zfs_nocacheflush = 1

For hardware (fiberchannel, iSCSI, SSA, ...) arrays with their own Cache 
this is a must.

> * Increase DNLC (Directory Name Lookup Cache)
> set ncsize = 500000

vmstat -s | grep 'total name lookups'
135562914356 total name lookups (cache hits 96%)

:-)
Unless the percent ratio is not below 90% increasing the DNLC is not so 
useful.

> Turn off atime of course.

Sure.

> Turn on LZJB compression for metapartition but gzip for
> the mail data filesystem. Our compression ratio on the mail
> filesystem is showing 1.68x.

Yes. GZIP for Mail, LZJB for Meta. Identical configuration here.

Pascal