Could the /usr/share/mdadm/mkconf script help? It can be used to print out the running equivalent of mdadm.conf It might be a good thing to use for comparisons, I use it a fair bit in my scripting with good results. Regards, Glenn On 18 November 2016 at 12:22, Peter Sangas <pete@xxxxxxxxxx> wrote: > 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 -- 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