Andy, Your question as prompted me to think about the following: I'm using Ubuntu 16 and have a running system with RAID1. If I change the hostname of the system do I need to make any changes to /etc/mdadm/mdadm.conf file and if so how do I do that? I see the host name is listed at the end of /etc/mdadm/mdadm.conf (name=hostname:0) for example. Thank you, Pete -----Original Message----- From: Andy Smith [mailto:andy@xxxxxxxxxxxxxx] Sent: Wednesday, November 16, 2016 7:53 PM To: linux-raid@xxxxxxxxxxxxxxx Subject: Newly-created arrays don't auto-assemble - related to hostname change? Hi, I feel I am missing something very simple here, as I usually don't have this issue, but here goes… I've got a Debian jessie host on which I created four arrays during install (md{0,1,2,3}), using the Debian installer and partman. These auto-assemble fine. After install the name of the server was changed from "tbd" to "jfd". Another array was then created (md5), added to /etc/mdadm/mdadm.conf and the initramfs was rebuilt (update-initramfs -u). md5 does not auto-assemble. It can be started fine after boot with: # mdadm --assemble /dev/md5 or: # mdadm --incremental /dev/sdc # mdadm --incremental /dev/sdd /etc/mdadm/mdadm.conf: DEVICE /dev/sd* CREATE owner=root group=disk mode=0660 auto=yes HOMEHOST <ignore> MAILADDR root ARRAY /dev/md/0 metadata=1.2 UUID=400bac1d:e2c5d6ef:fea3b8c8:bcb70f8f ARRAY /dev/md/1 metadata=1.2 UUID=e29c8b89:705f0116:d888f77e:2b6e32f5 ARRAY /dev/md/2 metadata=1.2 UUID=039b3427:4be5157a:6e2d53bd:fe898803 ARRAY /dev/md/3 metadata=1.2 UUID=30f745ce:7ed41b53:4df72181:7406ea1d ARRAY /dev/md/5 metadata=1.2 UUID=957030cf:c09f023d:ceaebb27:e546f095 I've unpacked the initramfs and looked at the mdadm.conf in there and it is identical. Initially HOMEHOST was set to <system> (the default), but I noticed when looking at --detail that md5 has: Name : jfd:5 (local to host jfd) whereas the others have: Name : tbd:0 …so I changed it to <ignore> to see if that would help. It didn't. So, I'd really appreciate any hints as to what I've missed here! Here follows --detail and --examine of md5 and its members, then the contents of /proc/mdstat after I have manually assembled md5. $ sudo mdadm --detail /dev/md5 /dev/md5: Version : 1.2 Creation Time : Thu Nov 17 02:35:15 2016 Raid Level : raid10 Array Size : 1875243008 (1788.37 GiB 1920.25 GB) Used Dev Size : 1875243008 (1788.37 GiB 1920.25 GB) Raid Devices : 2 Total Devices : 2 Persistence : Superblock is persistent Intent Bitmap : Internal Update Time : Thu Nov 17 02:35:15 2016 State : clean Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 Layout : far=2 Chunk Size : 512K Name : jfd:5 (local to host jfd) UUID : 957030cf:c09f023d:ceaebb27:e546f095 Events : 0 Number Major Minor RaidDevice State 0 8 48 0 active sync /dev/sdd 1 8 32 1 active sync /dev/sdc $ sudo mdadm --examine /dev/sd{c,d} /dev/sdc: Magic : a92b4efc Version : 1.2 Feature Map : 0x1 Array UUID : 957030cf:c09f023d:ceaebb27:e546f095 Name : jfd:5 (local to host jfd) Creation Time : Thu Nov 17 02:35:15 2016 Raid Level : raid10 Raid Devices : 2 Avail Dev Size : 3750486704 (1788.37 GiB 1920.25 GB) Array Size : 1875243008 (1788.37 GiB 1920.25 GB) Used Dev Size : 3750486016 (1788.37 GiB 1920.25 GB) Data Offset : 262144 sectors Super Offset : 8 sectors Unused Space : before=262056 sectors, after=688 sectors State : clean Device UUID : 4ac82c29:2d109465:7fff9b22:8c411c1e Internal Bitmap : 8 sectors from superblock Update Time : Thu Nov 17 02:35:15 2016 Bad Block Log : 512 entries available at offset 72 sectors Checksum : 96d669f1 - correct Events : 0 Layout : far=2 Chunk Size : 512K Device Role : Active device 1 Array State : AA ('A' == active, '.' == missing, 'R' == replacing) /dev/sdd: Magic : a92b4efc Version : 1.2 Feature Map : 0x1 Array UUID : 957030cf:c09f023d:ceaebb27:e546f095 Name : jfd:5 (local to host jfd) Creation Time : Thu Nov 17 02:35:15 2016 Raid Level : raid10 Raid Devices : 2 Avail Dev Size : 3750486704 (1788.37 GiB 1920.25 GB) Array Size : 1875243008 (1788.37 GiB 1920.25 GB) Used Dev Size : 3750486016 (1788.37 GiB 1920.25 GB) Data Offset : 262144 sectors Super Offset : 8 sectors Unused Space : before=262056 sectors, after=688 sectors State : clean Device UUID : 3a067652:6e88afae:82722342:0036bae0 Internal Bitmap : 8 sectors from superblock Update Time : Thu Nov 17 02:35:15 2016 Bad Block Log : 512 entries available at offset 72 sectors Checksum : eb608799 - correct Events : 0 Layout : far=2 Chunk Size : 512K Device Role : Active device 0 Array State : AA ('A' == active, '.' == missing, 'R' == replacing) $ cat /proc/mdstat Personalities : [raid1] [raid10] md5 : active (auto-read-only) raid10 sdd[0] sdc[1] 1875243008 blocks super 1.2 512K chunks 2 far-copies [2/2] [UU] bitmap: 0/14 pages [0KB], 65536KB chunk md3 : active raid10 sda5[0] sdb5[1] 12199936 blocks super 1.2 512K chunks 2 far-copies [2/2] [UU] md2 : active (auto-read-only) raid10 sda3[0] sdb3[1] 975872 blocks super 1.2 512K chunks 2 far-copies [2/2] [UU] md1 : active raid10 sda2[0] sdb2[1] 1951744 blocks super 1.2 512K chunks 2 far-copies [2/2] [UU] md0 : active raid1 sda1[0] sdb1[1] 498368 blocks super 1.2 [2/2] [UU] unused devices: <none> Cheers, Andy -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
