> On May 19, 2010, at 2:29 PM, Don wrote: > The data risk is a few moments of data loss. However, > if the order of the > uberblock updates is not preserved (which is why the > caches are flushed) > then recovery from a reboot may require manual > intervention. The amount > of manual intervention could be significant for > builds prior to b128.
This risk is mostly mitigated by UPS backup and auto-shutdown when the UPS detects power loss, correct? Outside of pulling the plug that should solve power related problems. Kernel panics should only be caused by hardware issues, which might corrupt the disk data anyway. Obviously software can and does fail, but the biggest problem I hear about with ZIL devices is behavior in a sudden power loss situation. It seems to me that UPS backup along with starting a shutdown cycle before complete power failure should prevent most issues. Seems like that should help with issues like the X25-E not honoring cache flush as well, the UPS would give it time to finish the writes. Again, without a firmware issue in the drive itself. Should be about the same as a supercap anyway. -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
