Scott Meilicke wrote: > So what happens during the txg commit? > > For example, if the ZIL is a separate device, SSD for this example, does it > not work like: > > 1. A sync operation commits the data to the SSD > 2. A txg commit happens, and the data from the SSD are written to the > spinning disk
#1 is correct. #2 is incorrect. The TXG commit goes from memory into the main pool. The SSD data is simply left there in case something bad happens before the TXG commit succeeds. Once it succeeds, then the SSD data can be overwritten. The only time you need to read from a ZIL device is if a crash occurs and you need those blocks to repair the pool. Eric _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
