From mboxrd@z Thu Jan 1 00:00:00 1970 From: Veljko Subject: Re: Linear device of two arrays Date: Fri, 21 Jul 2017 13:37:30 +0200 Message-ID: References: <20170705214250.0ea99538@natsu> <595D2ADA.8010907@youngman.org.uk> <5afd5cea-06b8-8524-e4f5-8534f23bd714@hardwarefreak.org> <87van15j9b.fsf@notabene.neil.brown.name> <87o9sn232n.fsf@notabene.neil.brown.name> <1eefd627-1aba-a795-05f0-d2106d3a62a3@gmail.com> <87shhyzhg5.fsf@notabene.neil.brown.name> <38e015fa-a07c-8f1a-3a04-384d973966be@gmail.com> <87d18uydir.fsf@notabene.neil.brown.name> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: NeilBrown , linux-raid@vger.kernel.org List-Id: linux-raid.ids Hello Neil, On 07/21/2017 11:15 AM, Veljko wrote: >> On 07/21/2017 12:00 AM, NeilBrown wrote: >> Bother. >> mdadm uses "parse_size()" to parse the offset, and this rejects >> "0", which makes sense for a size, but not for an offset. >> >> Just leave the "--data-offset=0" out. I checked and that is defintely >> the default for 1.0. > > Yes, now it works. I was able to create new linear device, restored the > saved 3M file and grown xfs. It was really fast and indeed, I'm happy. > > Thank you very much, Neil! Well, not without problems, it seams. I was having problem with root partition that was mounted read-only because of some problem with ext4. After fixing that on reboot, I still have extra space that was added with 4 new drives, but there are no md3 or md4. I'm mounting this device in fstab with UUID. I noticed that UUID for md4 was the same as md2 before rebooting. But if I use array UUID from examine of md2 (first member of linear raid), I get: mount: can't find UUID="24843a41:8f84ee37:869fbe7b:bc953b58" The one that works and that is in fstab is that one for md2 in by-uuid below. # cat /proc/mdstat Personalities : [raid1] [raid10] md2 : active raid10 sda4[4] sdd3[5] sdc3[7] sdb4[6] 5761631232 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU] md1 : active raid10 sda3[4] sdd2[5] sdc2[7] sdb3[6] 97590272 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU] md0 : active raid1 sda2[2] sdb2[3] 488128 blocks super 1.2 [2/2] [UU] No md3 or md4. Also, no mention of them in mdadm.conf # definitions of existing MD arrays ARRAY /dev/md/0 metadata=1.2 UUID=e5a17766:b4df544d:c2770d6e:214113ec name=backup1:0 ARRAY /dev/md/1 metadata=1.2 UUID=91560d5a:245bbc56:cc08b0ce:9c78fea1 name=backup1:1 ARRAY /dev/md/2 metadata=1.2 UUID=f6eeaa57:a55f36ff:6980a62a:d4781e44 name=backup1:2 or in dev: # ls /dev/md/ 0 1 2 or in /dev/disk/by-uuid: ls -al /dev/disk/by-uuid/ total 0 drwxr-xr-x 2 root root 120 Jul 21 12:11 . drwxr-xr-x 7 root root 140 Jul 21 12:11 .. lrwxrwxrwx 1 root root 10 Jul 21 12:15 64f194a4-7a3f-4cff-b167-ff6d8e70adff -> ../../dm-1 lrwxrwxrwx 1 root root 9 Jul 21 12:15 81060b25-b698-4cbd-b67f-d35c42c9482c -> ../../md2 lrwxrwxrwx 1 root root 10 Jul 21 12:15 b0285993-75db-48fd-bcd7-10d870e6069f -> ../../dm-0 lrwxrwxrwx 1 root root 9 Jul 21 12:15 dcfde992-2fe2-4da2-bb66-8c541a4bd473 -> ../../md0 --examine of md2 shows that this is a member of newly created linear md4 array: # mdadm --examine /dev/md2 /dev/md2: Magic : a92b4efc Version : 1.0 Feature Map : 0x0 Array UUID : 24843a41:8f84ee37:869fbe7b:bc953b58 Name : backup2:4 (local to host backup2) Creation Time : Fri Jul 21 10:58:07 2017 Raid Level : linear Raid Devices : 2 Avail Dev Size : 11523262440 (5494.72 GiB 5899.91 GB) Used Dev Size : 0 Super Offset : 11523262448 sectors State : clean Device UUID : d8931222:30af893e:9e0d2fe3:b18274ef Update Time : Fri Jul 21 10:58:07 2017 Bad Block Log : 512 entries available at offset -8 sectors Checksum : eff10ec - correct Events : 0 Rounding : 1024K Device Role : Active device 0 Array State : AA ('A' == active, '.' == missing, 'R' == replacing) This device and array has different UUID than one used for mounting the device in fstab. --detail on md2 still works. mdadm --detail /dev/md2 /dev/md2: Version : 1.2 Creation Time : Fri Sep 14 12:40:13 2012 Raid Level : raid10 Array Size : 5761631232 (5494.72 GiB 5899.91 GB) Used Dev Size : 2880815616 (2747.36 GiB 2949.96 GB) Raid Devices : 4 Total Devices : 4 Persistence : Superblock is persistent Update Time : Fri Jul 21 12:28:07 2017 State : clean Active Devices : 4 Working Devices : 4 Failed Devices : 0 Spare Devices : 0 Layout : near=2 Chunk Size : 512K Name : backup1:2 UUID : f6eeaa57:a55f36ff:6980a62a:d4781e44 Events : 2689052 Number Major Minor RaidDevice State 4 8 4 0 active sync set-A /dev/sda4 6 8 20 1 active sync set-B /dev/sdb4 7 8 35 2 active sync set-A /dev/sdc3 5 8 51 3 active sync set-B /dev/sdd3 --examine switch on partitions that are members of md2 or md3 shows that they know where they belong. Is there a procedure for finding the missing devices? I'm not really comfortable with this confusing situation. Regards, Veljko