From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Dawson Subject: Re: Can't mount Old RHEL 6 Raid with new install of CentOS 7, now can't mount with original RHEL 6 Date: Tue, 16 Aug 2016 11:35:51 -0600 Message-ID: <57d23adc6db12d6a365dd2c6f50d4bf5@celticblues.com> References: <42cee2e2d85a5b0e39efc34117e597a2@celticblues.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Chris Murphy , Linux-RAID List-Id: linux-raid.ids Sorry.. my bad... I am not using RHEL... I am using CentOS... mdadm --version = mdadm - v3.2.3 - 23rd December 2011 When I try to assemble the raid I get the following errors: sudo mdadm --assemble /dev/md127 /dev/sdb1 /dev/sdc1 I get the following: mdadm: /dev/md127 has been started with 2 drives. When I try to mount sudo mount /dev/md127 /proj I get the following: mount: you must specify the filesystem type When I specify the filesystem type, sudo mount -t ext4 /dev/md127 /proj/ I get the following: mount: wrong fs type, bad option, bad superblock on /dev/md127, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so =============================================== dmesg | tail =============================================== md: md127 stopped. md: bind md: bind bio: create slab at 1 md/raid0:md127: md_size is 3907039232 sectors. md: RAID0 configuration for md127 - 1 zone md: zone0=[sdc1/sdb1] zone-offset= 0KB, device-offset= 0KB, size=1953519616KB EXT4-fs (md127): VFS: Can't find ext4 filesystem =============================================== "sudo mdadm -D /dev/md127" results =============================================== /dev/md127: Version : 1.2 Creation Time : Fri Aug 5 16:46:10 2016 Raid Level : raid0 Array Size : 1953519616 (1863.02 GiB 2000.40 GB) Raid Devices : 2 Total Devices : 2 Persistence : Superblock is persistent Update Time : Fri Aug 5 16:46:10 2016 State : clean Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 Chunk Size : 512K Name : mymachine:0 (local to host mymachine) UUID : 8217dfb5:a97a15df:94a85926:3fea6697 Events : 0 Number Major Minor RaidDevice State 0 8 33 0 active sync /dev/sdc1 1 8 17 1 active sync /dev/sdb1 =============================================== "sudo mdadm --examine /dev/sdb1" results =============================================== /dev/sdb1: Magic : a92b4efc Version : 1.2 Feature Map : 0x0 Array UUID : 8217dfb5:a97a15df:94a85926:3fea6697 Name : mymachine:0 (local to host mymachine) Creation Time : Fri Aug 5 16:46:10 2016 Raid Level : raid0 Raid Devices : 2 Avail Dev Size : 1953519616 (931.51 GiB 1000.20 GB) Data Offset : 2048 sectors Super Offset : 8 sectors State : clean Device UUID : d9bab0d7:793e5168:4457d25b:24614a41 Update Time : Fri Aug 5 16:46:10 2016 Checksum : 744c405e - correct Events : 0 Chunk Size : 512K Device Role : Active device 1 Array State : AA ('A' == active, '.' == missing) =============================================== "sudo mdadm --examine /dev/sdc1" results =============================================== /dev/sdc1: Magic : a92b4efc Version : 1.2 Feature Map : 0x0 Array UUID : 8217dfb5:a97a15df:94a85926:3fea6697 Name : mymachine:0 (local to host mymachine) Creation Time : Fri Aug 5 16:46:10 2016 Raid Level : raid0 Raid Devices : 2 Avail Dev Size : 1953519616 (931.51 GiB 1000.20 GB) Data Offset : 2048 sectors Super Offset : 8 sectors State : clean Device UUID : a0dfb805:18718fed:6985075a:12fbb196 Update Time : Fri Aug 5 16:46:10 2016 Checksum : 7b2f5fd6 - correct Events : 0 Chunk Size : 512K Device Role : Active device 0 Array State : AA ('A' == active, '.' == missing) On 2016-08-11 20:38, Chris Murphy wrote: > On Thu, Aug 11, 2016 at 6:19 AM, John Dawson > wrote: >> I have a machine which had a drive with RHEL 6.X installed with a raid >> device setup on separate disk(s). Installed a new hard disk in machine >> and >> installed CentOS 7. CentOS 7 wouldn't mount the raid. Put the old >> drive >> back in and now RHEL 6.X won't mount the raid. Is the raid permanently >> hosed? Can I get the data on it back? How? Thx. > > RHEL comes with a support contract so you should contact Red Hat about > that part. > > Also, not anywhere near enough information has been provided, almost > like you think what you're experiencing is a widely known problem with > a known solution. But it isn't. So you should provide mdadm -E > information for each member block device, whether or not the array > assembles manually, if not what error do you get in user and kernel > space, and what command you're using to mount the array that you say > fails, and what the error message is. > > Also include mdadm version on both systems because few people will > have any idea what mdadm version is on the particular installation of > RHEL and CentOS you're using, as these things aren't standardized at > all across distros.