Date: Tue, 26 Apr 2016 15:09:17 +0200 From: InterNetX - Juergen Gotteswinter <jg@internetx.com> To: Miroslav Lachman <000.fbsd@quip.cz>, freebsd-fs@freebsd.org Subject: Re: How to speed up slow zpool scrub? Message-ID: <571F687D.8040103@internetx.com> In-Reply-To: <571F62AD.6080005@quip.cz> References: <571F62AD.6080005@quip.cz>
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to speed up the scrub itself you can try sysctl -w vfs.zfs.scrub_delay = 4 (default, 0 means higher prio) but be careful as this can cause a serious performance impact, the value can be changed on the fly your pool is raidz, mirror ? dedup is hopefully disabled? Am 4/26/2016 um 2:44 PM schrieb Miroslav Lachman: > Hi, > > is there any way to make zpool scrub faster? > We have one older machine with CPU Pentium(R) Dual E2160 @1.80GHz, 5GB > of RAM and 4x 4TB HDDs. It is just a storage for backups for about 20 > machines. > Scrub is scheduled from periodic each 30 days but it takes about 4 days > to complete and everything during scrub is slow. Backups takes 8 hours > instead of 5 (made by rsync), deleting of old files is even more slower. > > The backups are made every night from the midnight to morning, the > machine is idle for the rest of the day. > > Is there any tuning to make scrub faster in this idle time? > Or is it better to do it other way - slower scrub with even lower > priority taking for about one week but not affecting time of normal > operations? (is it dangerous to have scrub running this long or reboot > machine during the scrub?) > > I have a performance graphs of this machine and CPU is about 70% idle > during scrub, but hard drives are busy 75% (according to iostat) > > FreeBSD 10.3-RELEASE amd64 GENERIC > > Miroslav Lachman > _______________________________________________ > freebsd-fs@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org"
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