On 07/29/2012 04:07 PM, Jim Klimov wrote: > Hello, list Hi Jim,
> For several times now I've seen statements on this list implying > that a dedicated ZIL/SLOG device catching sync writes for the log, > also allows for more streamlined writes to the pool during normal > healthy TXG syncs, than is the case with the default ZIL located > within the pool. > > Is this understanding correct? Does it apply to any generic writes, > or only to sync-heavy scenarios like databases or NFS servers? Yes, it is correct. It applies to all writes. If the log is allocated on a slog devices, then the synchronous log records don't fragment the pool. As far as I understand it, txgs happen sequentially even with no slog device present, but the log entries don't - they occur as is needed to fulfill the sync write request with minimum latency. Cheers, -- Saso _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
