Way to prune/limit the ZFS zpool history?
Hello. I've been experimenting with a series scripts that takes ZFS snapshots every minute, eventually destroying the oldest so that only so many remain available for a given window of time. This may seem a trivial concern with hard drive sizes being what they are these days, but after running a zpool history I started thinking that a ZFS create and destroy being performed every minute would add up to a lot over the course of a few years (current estimate is 62MB/year for the naming scheme of my snapshots). From what I understand, ZFS compresses metadata by default, so this history probbaly won't take up much space in the grand scheme of things. However, I was curious just the same about wether or not there was a way to prune down, or limit the size of, the zpool history. Also, is there any substantial performance penalty to having a huge history? Thanks for any pointers. -- Geoff ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Way to prune/limit the ZFS zpool history?
In the last episode (Jan 20), Geoff Fritz said: I've been experimenting with a series scripts that takes ZFS snapshots every minute, eventually destroying the oldest so that only so many remain available for a given window of time. This may seem a trivial concern with hard drive sizes being what they are these days, but after running a zpool history I started thinking that a ZFS create and destroy being performed every minute would add up to a lot over the course of a few years (current estimate is 62MB/year for the naming scheme of my snapshots). According to http://docs.sun.com/app/docs/doc/819-5461/gdswe?l=ena=view , the zpool history file is between 128K and 32MB, depending on the size of the pool. The FreeBSD import at /sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa_history.c agrees with the docs :) -- Dan Nelson dnel...@allantgroup.com ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Way to prune/limit the ZFS zpool history?
On Tue, Jan 20, 2009 at 10:17:47PM -0600, Dan Nelson wrote: In the last episode (Jan 20), Geoff Fritz said: I've been experimenting with a series scripts that takes ZFS snapshots every minute, eventually destroying the oldest so that only so many remain available for a given window of time. This may seem a trivial concern with hard drive sizes being what they are these days, but after running a zpool history I started thinking that a ZFS create and destroy being performed every minute would add up to a lot over the course of a few years (current estimate is 62MB/year for the naming scheme of my snapshots). According to http://docs.sun.com/app/docs/doc/819-5461/gdswe?l=ena=view , the zpool history file is between 128K and 32MB, depending on the size of the pool. The FreeBSD import at /sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa_history.c agrees with the docs :) I always forget that ZFS is documented on Sun's site as well as the man pages. Hopefully some day the FreeBSD docs will catch up w/ Sun's. Thanks a bunch for the pointer. Very informative. -- Geoff ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
