From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: 9 second recovery when re-adding a drive that got kicked out? Date: Wed, 21 Jun 2017 07:02:33 +1000 Message-ID: <87efue2x06.fsf@notabene.neil.brown.name> References: <20170604223817.ntxlvafgfa2umww2@merlins.org> <87r2yxdazc.fsf@notabene.neil.brown.name> <20170620182745.rbufznqe4tuxqttq@merlins.org> <20170620183154.GA5303@merlins.org> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Return-path: In-Reply-To: <20170620183154.GA5303@merlins.org> Sender: linux-raid-owner@vger.kernel.org To: Marc MERLIN Cc: "linux-raid@vger.kernel.org" List-Id: linux-raid.ids --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue, Jun 20 2017, Marc MERLIN wrote: > On Tue, Jun 20, 2017 at 11:27:45AM -0700, Marc MERLIN wrote: >> On Tue, Jun 06, 2017 at 01:57:27PM +1000, NeilBrown wrote: >> > Had you run "mdadm --examine-bitmap /dev/sdk1" before the re-add, it >> > would have told you how many bits were set at that time. >> >=20 >> > That "x/y pages" information never should have appeared in /proc/mdstat >> > - it is really just of interest to developers. But it is there now, so >> > removing it is awkward. >>=20 >> So, I got the problem again, re-added a drive that had just been missing >> for maybe 2mn, and this time I'm getting a very long (but not full) >> recovery: >=20=20 > Mmmh, this is puzzling. > > The progress meter was wrong, it recovered in 3mn: > Jun 20 11:19:28 gargamel kernel: [ 916.007017] md: recovery of RAID arra= y md8 > Jun 20 11:22:41 gargamel kernel: [ 1108.395580] md: md8: recovery done. It is a progress bar - haven't you learned by now that they are *always* wrong :-) recovery always reports progress in sectors completed, and estimates time based on how many sectors were processes in the last 30 seconds, and how many are left. With a bitmap based recovery, most sectors are handled very quickly (instantly?), while some take milliseconds. That makes the estimate imprecise. NeilBrown > > Marc > --=20 > "A mouse is a device used to point at the xterm you want to type in" - A.= S.R. > Microsoft is to operating systems .... > .... what McDonalds is to gourmet c= ooking > Home page: http://marc.merlins.org/=20=20 > -- > 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----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAllJjWsACgkQOeye3VZi gbmhKxAAwjThkoWyAqBiOc8wGlQtlW1MYPLpNYA1wkC9HHw/IOksbpbnyJOYsdpr fCqnJskvdr4TdQAiSteY3f9lYIpFMZcnxgbgqHETOv/tXghtbvot5qLe8ySaKSWB TG1zBc4ysBsaWL5fYS2Jmh4mG7/kModFw5So1KY2eXLHPzVd4FsJUC371GCiF10n l9UrDgQiQAKwdrHzvHYhQ+Pr7Y7oyASLpbUm2zmc3gJ+3LgJN3X/FjVzDX8MGVlq LGAyDig1h5jBs4nNm9+1tfNRJ4/fcH6mcfVrS3YNwIGjA2sK67KzeKK4xNCqwCrk +3v71KQWRJf9VcjsmTk9IJjHHXhCVvgrtaNbBFWuFM+nOzPpWe1dqvKi0UUGV/pM MH1AOt1OAhS9EmW7dMvVcFv3sTVy3373UfwiXTNAxTr/mFPbx74U2b0wj72N2w6Z hwNegLIGEljvczImbfymbf12wCNCqsdx4srySHfkWVMWLQl6iQNcVktUUblP4/At +u+SfZHpJpHbkVisYeTw2eLBrFMzH9H3WyRJu8lQIEnberpHu3d/Gs1dMClTetAv sePHKKd4TiadzB8tHTDAAafVAPcRPeqx8HPaGkapyVVJpbjjT+WsVstSgc9VtGRg JElB7K2X8FnLLDgiTgri+LjTKFlu5vlvjcTivXXR5+dy8Yzv/hs= =WXO3 -----END PGP SIGNATURE----- --=-=-=--