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Re: Talking about RAID - disks with same id

Hi Joe,

thank you for the mesage

Joe Pfeiffer wrote:

> This is normal.  It's the identical UUIDs that tell the system that the
> partitions go into the same RAID array.
> Here's what I see when I look at my RAID disks:
> /dev/sda2: UUID="67d3c233-96a0-737c-5f88-ed9b936ea3ae"
> UUID_SUB="48b56869-6f19-21b9-283f-3eee3ac90cf8" LABEL="snowball:1"
> TYPE="linux_raid_member" PARTUUID="3bb3729a-528b-4384-b6a5-b6d9e148ed2a"
> /dev/sdb2: UUID="67d3c233-96a0-737c-5f88-ed9b936ea3ae"
> UUID_SUB="1f48f805-4173-78cd-1f52-957920f66335" LABEL="snowball:1"
> TYPE="linux_raid_member" PARTUUID="1bdd3893-9346-49d2-8292-a61075ad0c5e"

you see in your case PARTUUID is different for both members. In my case it
is identical and this is what is bothering me

> and here's the relevant line in my /etc/mdadm/mdadm.conf
> ARRAY /dev/md/1  metadata=1.2 UUID=67d3c233:96a0737c:5f88ed9b:936ea3ae
> name=snowball:1

It looks like the new style raid (I don't recall in which version it was
introduced). However this raid was created ~12y ago without metadata.

> But...  if this data is that important, you should be running backups.
> RAID is to keep you running if a disk fails, it isn't to keep you from
> losing data.

Indeed this is true - I make backups but not that often as data changes not
that often, however it might be good idea to run on regular bases.

I guess I'll have to sit over the weekend and make a plan.