Thx all, I understand now.
BR, Jeffry > > if an application requests a synchronous write then it is commited to > ZIL immediately, once it is done the IO is acknowledged to application. > But data written to ZIL is still in memory as part of an currently open > txg and will be committed to a pool with no need to read anything from > ZIL. Then there is an optimization you wrote above so data block not > necesarilly need to be writen just pointers which point to them. > > Now it is slightly more complicated as you need to take into account > logbias property and a possibility that a dedicated zil device could be > present. > > As Neil wrote zfs will read from ZIL only if while importing a pool it > will be detected that there is some data in ZIL which hasn't been > commited to a pool yet which could happen due to system reset, power > loss or devices suddenly disappearing. > > -- > Robert Milkowski > http://milek.blogspot.com > > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
