> The guide suggests that the zil be sized to 1/2 the amount of ram in the > server which would be 1GB.
The ZFS Best Practices Guide does detail the absolute maximum size the ZIL can grow in theory, which as you stated is 1/2 the size of the host's physical memory. But in practice, the very next bullet point details the log device sizing equation which we have found to be a more relevant indicator. Excerpt below: "For a target throughput of X MB/sec and given that ZFS pushes transaction groups every 5 seconds (and have 2 outstanding), we also expect the ZIL to not grow beyond X MB/sec * 10 sec. So to service 100MB/sec of synchronous writes, 1 GB of log device should be sufficient." > What happens if I oversize the zil? "Oversizing" the log device capacity has no negative repercussions other than the under utilization of your SSD. > If I create a 1GB slice for the zil, can I add another slice for another > zil in the future when more ram is added? If the question is if multiple disk slices can be striped to aggregate capacity, then the answer is yes. Be aware with most SSDs, including the Intel X25-E, using a disk slice instead of the entire device will automatically disable the on-board write cache. Christopher George Founder / CTO http://www.ddrdrive.com/ -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
