From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: RAID6 grow unexpected results Date: Fri, 23 Oct 2015 18:15:31 +1100 Message-ID: <87pp06xdgs.fsf@notabene.neil.brown.name> References: <87io5yzg1a.fsf@notabene.neil.brown.name> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Liwei , linux-raid@vger.kernel.org List-Id: linux-raid.ids --=-=-= Content-Type: text/plain Liwei writes: > On Fri, 23 Oct 2015 at 06:37 Neil Brown wrote: >> >> Liwei writes: >> >> > Hi list, >> > I tried growing a RAID6 array by executing the mdadm --add and >> > mdadm --grow --raid-devices commands. Usually that should run fine and >> > I can continue with pvresize. >> >> That is incorrect. You cannot run "pvresize" until the reshape >> completes. > > > Ah, my bad. It's been a while since I did that. So if I had been > patient, all would have been well? > >> >> >> > >> > This time however, the actual usable raid array size did not >> > change even though reshape begins. In my confusion, I decided to >> > reboot. That didn't solve the problem (and apparently the reshape was >> > interrupted, but mdadm shows the grown array as clean?) >> >> Clean is expected. It will be in an intermediate state, part has >> reshaped to extra devices, part is still the original. >> >> > >> > I then executed mdadm --grow --size=max, which seemed to have >> > increased the array size, but apparently by too much. Now I'm getting >> > "attempt to access beyond end of device" errors for each of the >> > component drives. A new reshape operation has also begun, which I >> > expect would fail as the array size is now too big. >> >> "--size" isn't the same as "--array-size". >> "--size" is the size of the component devices to use. >> >> The "attempt to access beyond end of device" errors are unexpected but >> presumably related o the "--size=max". Maybe the 'max' chosen was too >> large. That suggests a bug somewhere. >> You probably want to reduce that size back to where it was. > > > I just realised I got the wrong command. I used --array-size=max > instead. A reboot seemed to have reverted the change. > >> >> >> > >> > What did I do wrong and how can I remedy this? >> >> Could we start with "mdadm --examine" status of all devices, "mdadm >> --detail" of the array, and all kernel messages that could possibly >> relate to the array since you first started this exercise? > > > Eventually it was a foul up on my part. Things seem to be back to > normal after a reboot, and the reshape is in progress. Apologies for > the confusion! Good to know that thing are working - thanks. NeilBrown --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJWKd6UAAoJEDnsnt1WYoG5SicQAJnSyr7TIv1mFES+SvDUaVAi uB5dePu02b/w8nUwkyyNIyixL/7VUmFRzi6M4UVWH4RCk124XVA8bu0MGkkcQMiO S52I/PbCCUbZD3QLTtv1mXjHnwpiyY7HOvrySTBjTL/8hTONOBbtnrpTjRa/IZKN i8W2QRFoT4oaxyNX7d9dw/Yp962bby/+h66trRiPrLdGPk4IYBdkN+Lbjn3da/pi o8tEDHgZJx/wO874HuI3rO2ztmWuEr3jh/Ky7Ue5VGvi1gsaf3PMqHLmkuzPg/fj 6ueNX0RnHHYE2j0yCXG8yBKJ8AaC84QNpZDIJoDKdFB4dkm4zg6msWhKZAwHLp+F 1WUipi2uTdvQ15g+2sE+9uyvfAMboDoLRPnSVy/yGGPyCzb5rZRNUuEy8o32gnVJ guyIRBPVyCll8bub0RcPP98ZzrAE+SRCPpayk/R88dJmfaJv8omeMGbPQl5oI0EY aPUcVYAmlJ3QJpUrxIxVe8F7qX5yyr3Xg0tqQnDVeSmRSqdqrEDmr/KksM/OeMoW ioamXMCTzhbqvTALO3rMYJwT1jTA5XIFeYdzArcYWo3fKcoeZw+oNOACXbsNWtUp zYVZAYJtCceUlyRVJ61WelfMz+i2t+p6qRgSZekmX7D2rB9vBwt6tZWgF/G4ueXR XemX0bPW9mtCvs6bKoQD =mztb -----END PGP SIGNATURE----- --=-=-=--