Re: The "uniqueness" of UUIDs
Roger Price composed on 2024-11-26 08:51 (UTC+0100):
> On Tue, 26 Nov 2024, George at Clug wrote:
>> "$ lsblk -f" output is very nice ! Thanks.
> I tried this and noticed UUID duplication in the output. Here is part of what I
> saw:
> NAME FSTYPE FSVER LABEL UUID FSAVAIL FSUSE% MOUNTPOINT
> ...
> sdg
> ...
> ├─sdg6 linux_raid_member 1.0 10.218.0.100:3 f5e37a29-357a-e3f2-c731-e29eddce5e91
> │ └─md3 ext4 1.0 39c24711-ab43-497c-bf3e-12b4032575ac 758.4G 7% /mnt/home
> ...
> sdh
> ...
> ├─sdh6 linux_raid_member 1.0 10.218.0.100:3 f5e37a29-357a-e3f2-c731-e29eddce5e91
> │ └─md3 ext4 1.0 39c24711-ab43-497c-bf3e-12b4032575ac 758.4G 7% /mnt/home
> UUID sdg6 = UUID sdh6 ! If I wanted to retire /dev/sdg6 from the Raid array, I
> would not be able to use the UUID, only the unique SDxn.
> Aren't UUIDs supposed to be unique? Roger
Members of a raid filesystem have to be seen as an integral part of one filesystem,
a special case. It's another reason I stick to use of LABELs.
# lsblk -f | egrep -A1 'raid|NAME'
NAME FSTYPE FSVER LABEL UUID FSAVAIL FSUSE% MOUNTPOINTS
sda
--
├─sda5 linux_raid_member 1.0 msi85:0tmp 6cb3…
│ └─md0 ext4 1.0 hr18md0tmp 8aea…
├─sda6 linux_raid_member 1.0 msi85:1usrl f4e4…
│ └─md1 ext4 1.0 hr18md1usrl c3f3… 934.9M 75% /usr/local
├─sda7 linux_raid_member 1.0 msi85:2srv b290…
│ └─md2 ext4 1.0 hr18md2srv 7043… 5.9G 23% /srv
├─sda8 linux_raid_member 1.0 msi85:3hom 6594…
│ └─md3 ext4 1.0 hr18md3hom 71bc… 27.8G 59% /home
├─sda9 linux_raid_member 1.0 msi85:4 32c4…
│ └─md4 ext4 1.0 hr18md4 2d7d… 42.7G 79%
└─sda10 linux_raid_member 1.0 msi85:5iso 7f46…
└─md5 ext4 1.0 hr18md5iso 05f1… 32.4G 95% /isos
--
├─sdb5 linux_raid_member 1.0 msi85:0tmp 6cb3…
│ └─md0 ext4 1.0 hr18md0tmp 8aea…
├─sdb6 linux_raid_member 1.0 msi85:1usrl f4e4…
│ └─md1 ext4 1.0 hr18md1usrl c3f3… 934.9M 75% /usr/local
├─sdb7 linux_raid_member 1.0 msi85:2srv b290…
│ └─md2 ext4 1.0 hr18md2srv 7043… 5.9G 23% /srv
├─sdb8 linux_raid_member 1.0 msi85:3hom 6594…
│ └─md3 ext4 1.0 hr18md3hom 71bc… 27.8G 59% /home
├─sdb9 linux_raid_member 1.0 msi85:4 32c4…
│ └─md4 ext4 1.0 hr18md4 2d7d… 42.7G 79%
└─sdb10 linux_raid_member 1.0 msi85:5iso 7f46…
└─md5 ext4 1.0 hr18md5iso 05f1… 32.4G 95% /isos
#
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