From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: performance issue (was: Re: kernel: BUG: soft lockup - CPU#1 stuck for 60s!) Date: Mon, 26 Oct 2015 05:08:39 +0900 Message-ID: <87a8r6g188.fsf@notabene.neil.brown.name> References: <1092031595.20151015153830@oudeis.org> <87si5bvcj4.fsf@notabene.neil.brown.name> <43246687.20151024181541@oudeis.org> <20151024213139.5b20dec6@natsu> <16514313.20151025202337@oudeis.org> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha1; protocol="application/pgp-signature" Return-path: In-Reply-To: <16514313.20151025202337@oudeis.org> Sender: linux-raid-owner@vger.kernel.org To: Rainer =?utf-8?Q?F=C3=BCgenstein?= , Roman Mamedov Cc: Linux-RAID List-Id: linux-raid.ids --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Rainer F=C3=BCgenstein writes: > Hello Roman, > > Saturday, October 24, 2015, 6:31:39 PM, you wrote: > >> Use a higher bitmap-chunk size, such as 256M or more. > > I guess that would be > > mdadm --grow /dev/md0 --bitmap-chunk=3D256M ?? You would need to remove and then re-add the bitmap. So: mdadm --grow /dev/md0 --bitmap=3Dnone mdadm --grow /dev/md0 --bitmap=3Dintermnal --bitmap-chunk=3D256M =20=20 > > is it wise to issue this command during a re-sync? Depending on kernel version, it will either work or it won't. Either way, it won't cause harm. > > a cron.weekly job started the re-sync (although I'm pretty sure this > job has been disabled quite some time ago) Weekly is a bit more often than I would go for, but why disable it? Regular scanning for latent bad blocks is fairly important for reliability. > $ cat /proc/mdstat > Personalities : [raid6] [raid5] [raid4] > md0 : active raid5 sdb1[7] sdf1[3] sdc1[5] sde1[0] sdd1[8] > 11721061376 blocks super 1.2 level 5, 64k chunk, algorithm 2 [5/5] = [UUUUU] > [=3D=3D>..................] resync =3D 11.9% (348948608/2930265344= ) finish=3D7771.1min speed=3D5533K/sec > bitmap: 8/350 pages [32KB], 4096KB chunk That isn't a cronjob started resync. That would say "check" rather than 'resync". This looks a lot like a resync after an unclean restart. But with the bitmap that should go faster... What does "mdadm --examine-bitmap /dev/sdb1" report? NeilBrown > > unused devices: > > tnx & cu > > --=20 > Best regards, > Rainer mailto:rfu@oudeis.org > > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJWLTbIAAoJEDnsnt1WYoG5KekQALz0Z/veDnGddaN2oQwjmdVK LTW7Jw35mYvYzWm7TcbuIJ9AJL4mWUlMGwfJ5Wd8YmqJlagJf/iy6KgEogts54Tq VXMIT2ZzXD/ATcD1svi3KjNPXFQis68KrbpVbNyyk9+Uhgo1qTMg8mHHxZ2UB2dJ mwhlzTxt/vE84FNsTlyt3GYFeIxUZX24kmOBtoJuhUgsIzUDJujVML85fW6ppDve 8rnB6dzYYaCixu2lJ/MCGJx24fWyCPnduzzF2kiTmyT90vn1euZkVA6/d/LT6FKO SnrPgG2kzhXKkU937tF7iaA29DmDovHZ8Y8zeqfq/RuT0hfLAfS7s/AlaS8de0Yx o0j9vTGGWGBEpvmMyd2GynqeYVaBCPs507wxuHNYeaITqGKKRipJ/kpk8zuoNxxN oykqaj2v/spFea9wWIDrT8+6Jvj1PMq7ZegOklPSt8/q4EAxfrxxlffCrTL10ImV U9130tSE3SGmQC8qnp6J7On2mEPZ8Gs4lcG8H7NaeCdLk9IjFSHnEESJFYP0nEm4 ZBwfucqByAejI/mDlLkVhGIQ5eW7SnRjmF99FGiGQOxVOKWjKNAx7SL3YlPNGPyJ WCh6MHIt7U4Ysh35o175giLClhorAnzrPQHapffbeN4J52wxR6Mb2ysgxjt9S1t3 wR+g0emWg9UF92VnCcl3 =yUXh -----END PGP SIGNATURE----- --=-=-=--