Date: Wed, 27 Apr 2016 07:26:33 +0100 From: krad <kraduk@gmail.com> To: Miroslav Lachman <000.fbsd@quip.cz> Cc: jg@internetx.com, FreeBSD FS <freebsd-fs@freebsd.org> Subject: Re: How to speed up slow zpool scrub? Message-ID: <CALfReyf0nc=x3f5P5Q6C68sz8MN%2Be4xqqysWfBQqis_8cLxZwA@mail.gmail.com> In-Reply-To: <571F7AED.2040500@quip.cz> References: <571F62AD.6080005@quip.cz> <571F687D.8040103@internetx.com> <571F6EA4.90800@quip.cz> <CALfReyc9ki3-wEhkvvv=4TR28Nk0H0SvH8FAW=ev7H7Zu0oQoA@mail.gmail.com> <571F7AED.2040500@quip.cz>
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thats a shame. I have used an ssd on usb before with success, as their quality is usually better than pen drives. On 26 April 2016 at 15:27, Miroslav Lachman <000.fbsd@quip.cz> wrote: > krad wrote on 04/26/2016 16:02: > >> Erk, i would try to move your system off those data disks as you have >> two pools competing for the disk spindles. This is never ideal. You can >> by all means backup your os to those data pools but keep them on >> separate physical mediums. A couple of small SSD would do the trick >> nicely and could probably be added with no down time. You would probably >> want to find a suitable window though to make sure the box reboots >> nicely though. >> > > The system pool is really small - only 15GB and scrub is done relatively > fast. This machine cannot handle additional disks so I cannot move system > to other devices anyway. I tried system on USB flashdisk (read only) in the > past but it was slow and USB disk broke early. > > On 26 April 2016 at 14:35, Miroslav Lachman <000.fbsd@quip.cz >> <mailto:000.fbsd@quip.cz>> wrote: >> >> InterNetX - Juergen Gotteswinter wrote on 04/26/2016 15:09: >> >> to speed up the scrub itself you can try >> >> sysctl -w vfs.zfs.scrub_delay = 4 (default, 0 means higher prio) >> >> >> I will try it in the idle times >> >> 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? >> >> >> I forgot to mention it. Disks are partitioned to four partitions: >> >> # gpart show -l ada0 >> => 34 7814037101 ada0 GPT (3.6T) >> 34 6 - free - (3.0K) >> 40 1024 1 boot0 (512K) >> 1064 10485760 2 swap0 (5.0G) >> 10486824 31457280 3 disk0sys (15G) >> 41944104 7769948160 4 disk0tank0 (3.6T) >> 7811892264 2144871 - free - (1.0G) >> >> diskXsys partitions are used for base system pool which is 4-way >> mirror >> >> diskXtank0 partitions are used for data storage as RAIDZ >> >> # zpool list >> NAME SIZE ALLOC FREE EXPANDSZ FRAG CAP DEDUP HEALTH >> ALTROOT >> sys 14.9G 11.0G 3.92G - 79% 73% 1.00x ONLINE - >> tank0 14.4T 10.8T 3.56T - 19% 75% 1.00x ONLINE - >> >> >> # zpool status -v >> pool: sys >> state: ONLINE >> scan: scrub repaired 0 in 1h2m with 0 errors on Sun Apr 24 >> 04:03:54 2016 >> config: >> >> NAME STATE READ WRITE CKSUM >> sys ONLINE 0 0 0 >> mirror-0 ONLINE 0 0 0 >> gpt/disk0sys ONLINE 0 0 0 >> gpt/disk1sys ONLINE 0 0 0 >> gpt/disk2sys ONLINE 0 0 0 >> gpt/disk3sys ONLINE 0 0 0 >> >> errors: No known data errors >> >> pool: tank0 >> state: ONLINE >> scan: scrub in progress since Sun Apr 24 03:01:35 2016 >> 7.63T scanned out of 10.6T at 36.7M/s, 23h32m to go >> 0 repaired, 71.98% done >> config: >> >> NAME STATE READ WRITE CKSUM >> tank0 ONLINE 0 0 0 >> raidz1-0 ONLINE 0 0 0 >> gpt/disk0tank0 ONLINE 0 0 0 >> gpt/disk1tank0 ONLINE 0 0 0 >> gpt/disk2tank0 ONLINE 0 0 0 >> gpt/disk3tank0 ONLINE 0 0 0 >> >> errors: No known data errors >> >> >> # zdb | grep ashift >> ashift: 12 >> ashift: 12 >> >> >> Thank you for your informations. >> >> >>
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