From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: Linux RAID autodetect partitions go missing from /dev, but fdisk can see them Date: Tue, 16 Dec 2008 14:27:50 +1100 Message-ID: <18759.8246.568849.244513@notabene.brown> References: <49402CFE.3080708@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: message from Tor Arne Vestbo on Wednesday December 10 Sender: linux-raid-owner@vger.kernel.org To: =?ISO-8859-1?Q?Tor_Arne_Vestb=F8?= Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Wednesday December 10, torarnv@gmail.com wrote: > Hi all, >=20 > I have a very strange problem that I've been trying to debug for days > now. I'm hoping someone on this list may have ran into this before, o= r > have any tips on how I can continue debugging this, because I have to > admit I'm a little lost... Yes, it does sound rather weird. Can you: mdadm -Esv and mdadm --stop /dev/md0 strace -o /tmp/str -s 200 mdadm --assemble --scan --verbose /dev/md0 and send me the output and /tmp/str. Also the contents of /etc/mdadm.conf might help. Thanks, NeilBrown >=20 > I had a RAID5 with four drives and one spare, /dev/sd[bcde]1 + > /dev/sdf1, and everything was working fine, until one day one of the > drives in the array (sdb) no longer had a partition (sdb1). Letting t= he > spare take over I ignored this for a few days, but then it happened > again, this time with sdc. Kernel is 2.6.22.17, and I've compiled all > raid support in. The symptoms are: >=20 > - The kernel seems to detect the partitions (lines 396 and 407 in t= he > dmesg [1]) >=20 > - But once the boot process finishes and the RAID is started, there= is > no longer any sdc1 or sdb1, so the RAID fails to start (lines 550-576= in > dmesg [1]) >=20 > - Running fdisk -l shows that the drives in question (sdb and sdc) = do > have similar partitions as the other working drives, namely one Linux > RAID autodetect partition each (see command output [2]) >=20 > - But, the partitions are missing from /proc/partitions (see [3]) >=20 > - Manually adding device nodes using mknod works, but doing file -s= L > on the device gives "writable, no read permission", even though > permissions are the same as the other sd* nodes in /dev >=20 > - Running 'partprobe -s' successfully finds the two missing partiti= ons > and adds device nodes, and the nodes can be 'file -sL'ed, but when > trying to assemble the array again with these new nodes in the system= , > I'm told that sdc1 is not found, and after the --assemble is done, th= e > device nodes are once again missing (!) see [4] >=20 > - I've tried using the 'dmraid' command to look for fakeraid > partitions or meta data on the drives, which I was told could mess up > the auto-detection of Linux software ride partitions, but could not f= ind > any issues. >=20 >=20 > As you can tell I've exhausted all my current options, so any help on > what I could try next would be very much appreciated. I am especially > curious as to why I lose the partitions when mdadm tries to assemble = the > array? >=20 > Thanks! >=20 > Tor Arne Vestb=F8 >=20 > [1] http://pastebin.com/m15b9c275 dmesg > [2] http://pastebin.com/f50fb323a fdisk -l > [3] http://pastebin.com/f4547c2ca cat /proc/partitions > [4] http://pastebin.com/m4475c9ae partprobe + mdadm --assemble > -- > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html