+------------------------------------------------------------------------------ | On 2010-09-16 18:08:46, Ray Van Dolson wrote: | | Best practice in Solaris 10 U8 and older was to use a mirrored ZIL. | | With the ability to remove slog devices in Solaris 10 U9, we're | thinking we may get more bang for our buck to use two slog devices for | improved IOPS performance instead of needing the redundancy so much. | | Any thoughts on this? | | If we lost our slog devices and had to reboot, would the system come up | (eg could we "remove" failed slog devices from the zpool so the zpool | would come online..)
The ability to remove the slogs isn't really the win here, it's import -F. The problem is: If the ZIL dies, you will lose whatever writes were in-flight. I've just deployed some SSD ZIL (on U9), and decided to mirror them. Cut the two SSDs into 1GB and 31GB partitions, mirrored the two 1GBs as slog and have the two 31GB as L2ARC. So far extremely happy with it. Running a scrub during production hours, before, was unheard of. (And, well, "production" for mail storage is basically all hours, so.) As for running non-mirrored slogs... dunno. Our customers would be pretty pissed if we lost any mail, so I doubt I will do so. My SSDs were only $90 each, though, so cost is hardly a factor for us. Cheers. -- bdha cyberpunk is dead. long live cyberpunk. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
