From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: Hi! Strange issue with LSR -- bitmaps hadn't been used during 2 of 3 RAIDs resync Date: Mon, 28 May 2012 11:45:50 +1000 Message-ID: <20120528114550.417ae379@notabene.brown> References: <20120527220007.64fb230b@notabene.brown> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/2+w6vQqSaINdOYgk6v8hHNS"; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Igor M Podlesny Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/2+w6vQqSaINdOYgk6v8hHNS Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Mon, 28 May 2012 00:10:33 +0800 Igor M Podlesny wrote: > On 27 May 2012 20:00, NeilBrown wrote: > > On Sun, 27 May 2012 19:32:40 +0800 Igor M Podlesny > > wrote: > >> =C2=A0 =C2=A0A power outage has happened to system (which was in "susp= end" > >> state) with RAID-10, RAID-5 and RAID-6. Later on boot, RAID-10 was > >> fast re-synced using bitmap, but both RAID-5 and RAID-6 were in > >> auto-readonly mode with resync=3DDELAYED. When they flipped to > >> Read-Write, LSR started re-syncing not using bitmaps seemingly. A bug? > > > > Maybe. =C2=A0But with so little detail it is hard to say. > > What made you think the bitmaps weren't being used? >=20 > Well, it is reasonable to assume that host being put in suspend > mode wouldn't have much not synced data at all. RAID-10 had been > progressing its resync quite fast, it was obvious that it had been > using bitmaps for that. Moreover =E2=80=94 RAID-10 was the most I/O active > comparing to others, AFAIR. Unfortunately vague statements about "it was obvious" or "AFAIR" don't real= ly help in analysing a situation to find any bugs. I can only really work with concrete facts. Without them I cannot help. >=20 > > Did that arrays still have their bitmaps? >=20 > I still have that RAID-6, yep: >=20 > md127 : active raid6 sdg5[2] sdf5[6] sde5[7] sda5[0] sdd5[3] sdc5[1] > 1071984640 blocks super 1.0 level 6, 1024k chunk, algorithm 2 > [6/6] [UUUUUU] > bitmap: 0/1 pages [0KB], 131072KB chunk >=20 > > Where they degraded? >=20 > No way. >=20 > > How many bits were set in the bitmaps (probably too late to check now)? >=20 > Please see above. And the RAID-5 one was recently dismissed, alas. >=20 > > Is it reproducable ? =C2=A0... OK, I don't really expect you to try to = reproduce > > it, but if you could that would be awesome! >=20 > Well, might be VirtualBox would allow for such kind of experiment, dun= no. ) >=20 > P. s. Oh, and BTW, I see 2.6.18 supplied by RedHat still has the > bug causing kernel panic when using WIB -- couldn't you please point > out is it due to they're missing some important bugfix you made later? I have no time or interest for submiting bug reports to distros that I don't use. If the presence of the bug concerns you, I suggest you report it. NeilBrown >=20 > -- --Sig_/2+w6vQqSaINdOYgk6v8hHNS Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBT8LYzjnsnt1WYoG5AQI0ORAAulLQdsV4FmQIYFE+GMQDuQfrH7c3k8b1 20lAmS7OyWutWAvHUYey16C29SUlTYEy+5MzAJlm7awAXxKawdUYAcT4RppgueKD H93h823f/XaeY3Wk+h4acg1LbCBeCaCPJbTFtdyDWGe8Mytdww7mfQszb43yDAtw BufxIM4WR2ysXUEwRTtuEFi0nzHKgQPlEoaIl2kdEP4F262Tuliy607Or7VTgx8J CsQdr3Fhy0Y1qcEH0ICBspMmZpysHM9wl27T5bepPm8oG9P8dFbnYOOMwyi8VM4C HSfBQDKUUcVnJztPQeWd6LJuZUIEHMQnHIPNRSCXouzg4T56Nx/fNjFJHgrg2vRI 5M1TedUQYjKLlr6U7L842vd7O32+TeTzJKJgmA5mT7eRpHMgSUx72UOy37zOcaPz //gepQt+KTkMISMVPo6jJ8rlVbvhJnWkRlhtnocq5WhRJ2ukhJPJXGCuqq/g43oj oCz5zEGTmbC334D7Rml57scBHPljkgRb84dK4Ibdvo9sidxTNf11S4jSct67mALz uflt2y0zIsmJ7gfZRZXcFD2l8oYKLstef5DF3UdRhxJ62Z2qkqs8C7RJakgHRYot gMtQhkz7y0jTzQNv5bGsmG8RtfUrBbP7sNDxzzuAT+hvD9n5TAQYBO0ujNiZbDFM 3k0UulxSnII= =qd4I -----END PGP SIGNATURE----- --Sig_/2+w6vQqSaINdOYgk6v8hHNS--