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: Tue, 26 Jun 2012 16:18:46 +1000 Message-ID: <20120626161846.08489b0a@notabene.brown> References: <20120527220007.64fb230b@notabene.brown> <20120528114550.417ae379@notabene.brown> <20120528125436.69e847ca@notabene.brown> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/PYNsS6fEgqNVHPs+zQ7RVEW"; 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_/PYNsS6fEgqNVHPs+zQ7RVEW Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Wed, 20 Jun 2012 10:49:32 +0800 Igor M Podlesny wrote: > On 28 May 2012 12:03, Igor M Podlesny wrote: > > On 28 May 2012 10:54, NeilBrown wrote: > > [...] > >> The best indicator is total time that it takes (which can probably be > >> extracted from logs as start and end are logged). =C2=A0Divide that in= to size of a > >> device to get average MB/sec. =C2=A0If the bitmap was used, that will = normally be > >> much less the best throughput of the device. > > > > =C2=A0 That's exactly why I am stating it didn't use WIBs 2 times of 3.= It > > went resyncing from beginning till the end -- I had my finger on its > > pulse. :) > > > > =C2=A0 I can't promise (due to popular "lack of time" disease, yeah), b= ut > > if I'll get on it using VirtualBox or real environment [Lord forbid > > :)] once again, I'll let you know, sure. >=20 > Here it is: http://pastie.org/4118133 This doesn't appear to show the "start to end" that I suggested, just 10% to 30%, but it does suggest that the bitmap isn't speeding things up at all, at least for that part of the array... That is assuming you are talking about md124. I note that md125 doesn't have a bitmap. Is that what you are referring to? The next thing to do would be to look at the bitmap immediately after reboot to see how many bits are set. Maybe lots are set for some reason. >=20 > =E2=80=94 3.4.2-rt10 went suspend ok for 2 times, the 3rd it didn't. > Reboot, resync, no bitmaps use. >=20 > And, BTW, it's rather slow in despite of having max. stripe_cache_size= set. >=20 A larger stripe cache isn't going to affect resync speed much (I think). 50MB/sec on each drive seems fairly good to me. What were you expecting? NeilBrown --Sig_/PYNsS6fEgqNVHPs+zQ7RVEW Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBT+lURjnsnt1WYoG5AQJHQA/8DjGtrjCM24WxHhmGOR4bQFODZFkEpKfE BHyotRi/roY8sEDfVl5vKcKK7jpDGVB6xCeGq9xN3eGidF1euYr+hzAZBDisYv5M bI8soKbNzcAr+Y/GdpDT9mc13wudTBOKyfsOvv5pTvSW5woYzn40msnCeoc47D1T gZys9LEPJSa7y3n/vMHY3Z7O5ZyQIxhY0gzMFYy0snfef6ps/W0TCqZYdoSjrJPu eUTtwCLYx8X//nY7wJD1GQZm/BPpfhSHfXpUiTCWgNu12NUog+lfWiboYamb+eLA 4JdRxdd7mLz2+z9iAMZU0FJlQI3yovdYz0BXQAGl01BOJfTrXWvhY0wMXcBJ01AM xohL09flyGKWlJtHpZReiPA4k7pzJofmXLw0YF4rd1Vsf6zk+Sn/E6epamjCblz1 M9NVLc75+YqNK7vT8jIaNhLnTGkH9yYqY6op4C2pQgM6DiBLd1QwsqdWV9FN5SPi IsrXHM2Im7ek5AOmqgFsMoS0k1JdnWAw6lkOtXdgLAD/pHU6N47EnkrjVO3vowM7 IHkJLao8y/keFcWnCVDLg4StyuUBhi3YVaNRg8IOef5pSmVMOt8MDuk5DVtsVNlE yYvkIA+jhs1bQFOlZ8+8gwr1uqqA2QFQxguFeIO5q2d/ofqQ3VEX9Ngc4MTX98pa B6mZ5bXL/hE= =zox/ -----END PGP SIGNATURE----- --Sig_/PYNsS6fEgqNVHPs+zQ7RVEW--