I am wondering if the following idea makes any sense as a way to get ZFS to cache compressed data in DRAM?

In particular, given a 2-way zvol mirror of highly compressible data on persistent storage devices, what would go wrong if I dynamically added a ramdisk as a 3rd mirror device at boot time?

Would ZFS route most (or all) of the reads to the lower latency DRAM device?

In the case of an un-clean shutdown where there was no opportunity to actively remove the ramdisk from the pool before shutdown would there be any problem at boot time when the ramdisk is still registered but unavailable?

Note, this Gedanken experiment is for highly compressible (~9x) metadata for a non-ZFS filesystem.

Thanks.


--
Stuart Anderson  ander...@ligo.caltech.edu
http://www.ligo.caltech.edu/~anderson



_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

Reply via email to