On 03/06/09 14:51, Miles Nordin wrote:
"np" == Neil Perrin <neil.per...@sun.com> writes:np> Alternatively, a lockfs will flush just a file system to np> stable storage but in this case just the intent log is np> written. (Then later when the txg commits those intent log np> records are discarded). In your blog it sounded like there's an in-RAM ZIL through which _everything_ passes, and parts of this in-RAM ZIL are written to the on-disk ZIL as needed.
Thats correct.
so maybe I was using the word ZIL wrongly in my last post.
I understood what you meant.
are you saying, lockfs will divert writes that would normally go straight to the pool, to pass through the on-disk ZIL instead?
- Not instead but as well. The ZIL (code) will write immediately to the stable intent logs, then later the data cached in the ARC will be written as part of the pool transaction group (txg). As soon as that happens the intent log blocks can be re-used.
assuming any separate slog isn't destroyed while the power's off, lockfs and sync should get you the same end result after an unclean shutdown, right?
Right. Neil. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
