Arch Linux

Iriomote

Member

Registered: 2013-11-10

Posts: 29

Cannot create RAID5 with journal

Hi there, long time arch user here.

I'm trying to create a RAID5 array with an additional journaling partition.

The disklayout is as follows:

root@nas ~# blkid
/dev/sda1: UUID="3218-D009" TYPE="vfat" PARTUUID="6c4db833-e002-9b4a-8597-db5934455f3f"
/dev/sda2: UUID="7aefe7e5-935e-4c77-8a29-c89f52abbf2b" TYPE="crypto_LUKS" PARTUUID="c2fdab8e-996b-4a47-991b-303b96c2a151"
/dev/sda3: UUID="170e617b-57fd-451a-81f3-1af277acc9cc" TYPE="swap" PARTUUID="6c8868fd-2398-f84d-8479-027654f9fc89"
/dev/mapper/root: UUID="c4ef1966-b62c-43a8-b39c-23a955d621ae" TYPE="ext4"
/dev/sda4: PARTUUID="ed52d7f2-9937-b640-b6c2-a0b4d20c6c73"
/dev/sdb1: PARTUUID="ce856575-bbce-fd46-aca7-0b8b5a1e1462"
/dev/sdc1: PARTUUID="e5bb847d-362b-d140-9b1f-2858c7cd78c4"
/dev/sdd1: PARTUUID="db235b4c-8cb0-ff43-9800-d2f3ddbd519c"

I want to use sdb1 sbc1 and sdd1 for the RAID and sda4 for journaling.

root@nas ~# mdadm --create --verbose --level=5 --name=data-raid --metadata=1.2 --chunk=256 --raid-devices=3 /dev/md/data-raid /dev/sdb1 /dev/sdc1 /dev/sdd1 --write-journal=/dev/sda4
mdadm: layout defaults to left-symmetric
mdadm: size set to 3906837504K
mdadm: automatically enabling write-intent bitmap on large array
mdadm: RUN_ARRAY failed: Invalid argument

If I leave the journaling device out, it works and starts building the array.
The wiki mentions nothing about journaling, i got everything out of the man page for mdadm.

loqs

Member

Registered: 2014-03-06

Posts: 17,373

Re: Cannot create RAID5 with journal

Welcome to the arch linux forums Iriomote.  What about

mdadm --create --verbose --level=5 --name=data-raid --metadata=1.2 --chunk=256 --raid-devices=3 /dev/md/data-raid /dev/sdb1 /dev/sdc1 /dev/sdd1 --write-journal /dev/sda4

Iriomote

Member

Registered: 2013-11-10

Posts: 29

Re: Cannot create RAID5 with journal

I get the same cryptic error message. No change.

Last edited by Iriomote (2019-05-23 04:41:45)

frostschutz

Member

Registered: 2013-11-15

Posts: 1,418

Re: Cannot create RAID5 with journal

uname -a? if the kernel is too old then you have the situation that mdadm supports journal but kernel does not and they have an error communicating with each other

otherwise check dmesg for additional messages

Last edited by frostschutz (2019-05-23 07:26:44)

Iriomote

Member

Registered: 2013-11-10

Posts: 29

Re: Cannot create RAID5 with journal

My machine was installed just yesterday, so everything is up to date.

After some more digging in the manual for mdadm I fond the solution.
The Flag "--bitmap=none" is needed for whatever reason.
My Ubuntu Test-VM didn't need the flag.

So i did this:

root@arschinas ~# mdadm --create /dev/md/dataraid --verbose -c 256K -N dataraid --level=5 --homehost=any --consistency-policy=journal --bitmap=none --raid-devices=3 --write-journal=/dev/sda4 /dev/sdb1 /dev/sdc1 /dev/sdd1
mdadm: layout defaults to left-symmetric
mdadm: layout defaults to left-symmetric
mdadm: /dev/sda4 appears to be part of a raid array:
       level=raid5 devices=3 ctime=Thu May 23 17:36:22 2019
mdadm: /dev/sdb1 appears to be part of a raid array:
       level=raid5 devices=3 ctime=Thu May 23 17:36:22 2019
mdadm: /dev/sdc1 appears to be part of a raid array:
       level=raid5 devices=3 ctime=Thu May 23 17:36:22 2019
mdadm: /dev/sdd1 appears to contain an ext2fs file system
       size=3906969600K  mtime=Thu Jan  1 01:00:00 1970
mdadm: /dev/sdd1 appears to be part of a raid array:
       level=raid5 devices=3 ctime=Thu May 23 17:36:22 2019
mdadm: size set to 3906935808K
Continue creating array? y
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md/dataraid started.

The array is currently building and everything seems fine.