From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: /dev/md0 can't be created Date: Wed, 1 Apr 2015 13:53:21 +1100 Message-ID: <20150401135321.2f421b96@notabene.brown> References: <1215809785.2787621.1427263359309.JavaMail.zimbra@redhat.com> <12135556.2792023.1427264134774.JavaMail.zimbra@redhat.com> <20150325173529.13a6efd7@notabene.brown> <200110393.3671122.1427355395924.JavaMail.zimbra@redhat.com> <160793753.4322898.1427436381735.JavaMail.zimbra@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/RA61bg.Srbc3a=i_2=flPy7"; protocol="application/pgp-signature" Return-path: In-Reply-To: <160793753.4322898.1427436381735.JavaMail.zimbra@redhat.com> Sender: linux-raid-owner@vger.kernel.org To: Xiao Ni Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/RA61bg.Srbc3a=i_2=flPy7 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Fri, 27 Mar 2015 02:06:21 -0400 (EDT) Xiao Ni wrote: >=20 > I'm lucky, I reproduced it again and I ran the command udevadm monitor = > monitor before test. > I'll put it in as an attachment. >=20 > I found there is a not whole message in the last line.=20 >=20 > Xiao The line: UDEV [7083.531441] add /devices/virtual/block/md0 (block) confirms that udev saw an 'add' event for /dev/md0. That should be enough for udev to create the device node. If it doesn't, you need to look into udev and find out why it doesn't. I can't really help you there - I don't find udev very easy to debug. NeilBrown >=20 > ----- Original Message ----- > > From: "Xiao Ni" > > To: "NeilBrown" > > Cc: linux-raid@vger.kernel.org > > Sent: Thursday, March 26, 2015 3:36:35 PM > > Subject: Re: /dev/md0 can't be created > >=20 > > Hi Neil > >=20 > > I can reproduce it now. Do you want me to run udevadm monitor before= the > > test? > > And I checked the /var/log/messages, it show the information: > >=20 > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-7 operational= as > > raid disk 5 > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-6 operational= as > > raid disk 4 > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-5 operational= as > > raid disk 3 > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-4 operational= as > > raid disk 2 > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-3 operational= as > > raid disk 1 > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-2 operational= as > > raid disk 0 > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: allocated 0kB > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: raid level 5 active wit= h 6 > > out of 7 devices, algorithm 2 > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid456: discard support disabled= due > > to uncertainty. > > Oct 20 19:59:59 ibm-z10-25 kernel: Set > > raid456.devices_handle_discard_safely=3DY to override. > > Oct 20 19:59:59 ibm-z10-25 kernel: md0: detected capacity change from 0= to > > 1881145344 > > Oct 20 19:59:59 ibm-z10-25 kernel: md: recovery of RAID array md0 > > Oct 20 19:59:59 ibm-z10-25 kernel: md: minimum _guaranteed_ speed: 1000 > > KB/sec/disk. > > Oct 20 19:59:59 ibm-z10-25 kernel: md: using maximum available idle IO > > bandwidth (but not more than 200000 KB/sec) for recovery. > > Oct 20 19:59:59 ibm-z10-25 kernel: md: using 128k window, over a total = of > > 306176k. > > Oct 20 19:59:59 ibm-z10-25 systemd-udevd: inotify_add_watch(7, /dev/md0= , 10) > > failed: No such file or directory > > =20 > > Xiao > >=20 > > ----- Original Message ----- > > > From: "NeilBrown" > > > To: "Xiao Ni" > > > Cc: linux-raid@vger.kernel.org > > > Sent: Wednesday, March 25, 2015 2:35:29 PM > > > Subject: Re: /dev/md0 can't be created > > >=20 > > > On Wed, 25 Mar 2015 02:15:34 -0400 (EDT) Xiao Ni wro= te: > > >=20 > > > > Hi all > > > >=20 > > > > I have encountered so many times, the raid device is created > > > > successfully, but the directory > > > > /dev/md0 can't be created. It can't reproduce 100%. > > > >=20 > > > > [root@intel-sugarbay-do-01 create_assemble]# cat /proc/mdstat > > > > Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] > > > > md0 : active raid10 loop7[7](S) loop6[6] loop5[5] loop4[4] loop3[3] > > > > loop2[2] loop1[1] loop0[0] > > > > 1788416 blocks super 1.2 512K chunks 2 near-copies [7/7] [UUU= UUUU] > > > > bitmap: 0/1 pages [0KB], 65536KB chunk > > > >=20 > > > > unused devices: > > > > [root@intel-sugarbay-do-01 create_assemble]# ls /dev/md0 > > > > ls: cannot access /dev/md0: No such file or directory > > > >=20 > > > > The underline devices are loop devices which are created with b= ig > > > > file. > > > >=20 > > > > The kernel I used is RHEL7 (3.10.0-234.el7.x86_64.debug, mdadm - > > > > v3.3.2 > > > > - 21st August 2014) > > > > I'll try to reproduce this with upstream kernel and mdadm. But I th= ink it > > > > shouldn't be the problem about kernel. > > > >=20 > > > > What do you think I should check for this? And which tool is > > > > responsible for creating the directory? Maybe > > > > I can add some log to it to find the reason. > > > >=20 > > >=20 > > > /dev/md0 is created by udev. > > > Run > > > udevadm monitor > > >=20 > > > to see the events that udev is processing. When and ADD event for "m= d0" is > > > processed, /dev/md0 should get created. > > >=20 > > > NeilBrown > > >=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 > >=20 --Sig_/RA61bg.Srbc3a=i_2=flPy7 Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIVAwUBVRtdoTnsnt1WYoG5AQKJChAAul23nttZ26BVxEu030atL1bBNogpDAH/ qquyj8+TxuSb5pPgn0BUDklsptjndWkmcWTbQWjiWTJrQ646ULSjutikeK6Z+iT8 TmO5E861EVhZjEcmYJ0PKSf4xMWdj/hPJKGnGeBEvCMrJyLs2mbihkCBXJ/SpVM2 HA1Rl5qL7CHCqqRl/59tg2u+VBxACDtbbimb/jHhP/29AO287BSvqJ7fDyJSbVIt sdS65aZaAlivSXBn8b1CPaGpSNgP+A9bDgeTFFvmpoME92J6Cmu/MRoel17ZOPOH m11m90j3pukoMHbLEs8Pwlu9SUx9rVYVPYYiaJ8zIsdqbyQgmW9fIpH8j4AaDrei MQpMnVtcIdiJhNoSqCBfD85v3dTpyDPVBCLwH9fuwU4VzTjFCcuwjq2Rp80X7byw St5n6IVQlqDRAA6PmgmAYKM5oHb4ZruW8aZ6z0bMl48ldXGz7LA7Z8FaAgUHpD/z OFaxH58OykHeFARbnrp3H5IpqgTROAGV6YdBtMUu0B/2at2vY8u+jKk403Dw2naZ Fx2tWWP0BZiyEF9Bj89YyZptf2aEkZrT5shMz646EP1uj6FTD6Wv536dKm5DmZNh w00VkOn4stDEeA5MordAKY6EBslyUe1vE6n3Y/fAA+dIvd38hNxmyCKP1ueIskcM ysKoKhyEtcI= =d73h -----END PGP SIGNATURE----- --Sig_/RA61bg.Srbc3a=i_2=flPy7--