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skolima
Asked: 2011-05-09 06:16:33 +0800 CST

How do I rename an mdadm raid array?

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I have assembled a new raid array to replace an old one. However, this new array got assigned an automatic name of /dev/md127 and I want to rename it to /dev/md3, so that I don't have to change various other settings. How do I rename an mdadm raid array?

linux raid mdadm

3 Answers

  1. Best Answer

    Start with mdadm --detail /dev/md127:

    Version : 0.90
Creation Time : Wed Apr 13 20:03:21 2011
Raid Level : raid10
Array Size : 656765952 (626.34 GiB 672.53 GB)
Used Dev Size : 437843968 (417.56 GiB 448.35 GB)
Raid Devices : 3
Total Devices : 2
Preferred Minor : 8
Persistence : Superblock is persistent

    The first line shows the metadata version used by this array. Now, stop the array:

    mdadm --stop /dev/md127
mdadm --remove /dev/md127

    And assemble it again using the new name. If the metadata version is 1.0 or higher, use this:

    mdadm --assemble /dev/md3 /dev/sd[abcdefghijk]3 --update=name

    For arrays using old metadata structure (most likely 0.90, as it allows for kernel auto-assembly), use this:

    mdadm --assemble /dev/md3 --update=super-minor /dev/sd[abcdefghijk]3
    • 11

  2. I was in a similar position--I had an array I created which was re-named to /dev/md127 after reboot.

    The code

    mdadm --stop /dev/md127

    mdadm --assemble /dev/md3 /dev/sd[cdef]1

    was enough to get the md array re-named /dev/md3 for me, but like everyone else, after a reboot, it would revert back to /dev/md127

    I found that if I re-assembled the md array back to /dev/md3, and then re-created the initramfs file (dracut --force as I am on CentOS), then it would remember my array's name (/dev/md3) after reboots.

    • 5

  3. The other answers work, but if you don't want to stop your array prematurely, see here: How-to change the name of an MD device (mdadm) (from superuser)

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