Date: Wed, 20 Jul 2005 06:43:15 -0500 From: Eric Anderson <anderson@centtech.com> To: Skylar Thompson <skylar@cs.earlham.edu> Cc: FreeBSD Current <freebsd-current@freebsd.org> Subject: Re: mksnap_ffs takes 4-5 minutes? Message-ID: <42DE38D3.8010606@centtech.com> In-Reply-To: <20050720040336.GA69292@quark.cs.earlham.edu> References: <42DD64AB.3000605@centtech.com> <20050720040336.GA69292@quark.cs.earlham.edu>
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Skylar Thompson wrote: > On Tue, Jul 19, 2005 at 03:38:03PM -0500, Eric Anderson wrote: > >>Last week, I tried making a snapshot of one of my NFS servers' >>partitions. I've done this one other machines before, with smaller >>barely used partitions, and it has always been relatively snappy. >> >>This time, when I ran mksnap_ffs, the command took nearly 5 minutes, in >>which time all NFS traffic was suspended, as well as all disk access on >>the machine. After reading in the FreeBSD Implementation book >>(McKusick), it claims it should be very very fast. >> >>Anyone know why it should take so long to do this snapshot? Is this >>expected normal behaviour, or should I expect faster snapshots? >> >>Here's some info on the filesystem: >>Filesystem 1K-blocks Used Avail Capacity iused ifree >>%iused Mounted on >>/dev/da1s1d 406234604 91799154 281936682 25% 1300303 51197103 >> 2% /scr03 >> >>/dev/da1s1d on /scr03 (ufs, NFS exported, local, soft-updates) > > > Does that filesystem have a lot of open files? I believe all busy inodes > have to be copied in the snapshot process. > It probably did, however I ran the same test on a filesystem even larger (15million used inodes, 229million inodes free), that took 30minutes, with no open files! Eric -- ------------------------------------------------------------------------ Eric Anderson Sr. Systems Administrator Centaur Technology A lost ounce of gold may be found, a lost moment of time never. ------------------------------------------------------------------------
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