Re: Talking about RAID - disks with same id

From	Pascal Hambourg <pascal@plouf.fr.eu.org>
Newsgroups	linux.debian.user
Subject	Re: Talking about RAID - disks with same id
Date	2017-11-12 17:20 +0100
Message-ID	<uL39f-2tm-5@gated-at.bofh.it> (permalink)
References	<uJGop-4j2-5@gated-at.bofh.it> <uK3XH-2Vo-1@gated-at.bofh.it> <uKcHD-J9-1@gated-at.bofh.it> <uKkYy-6dO-5@gated-at.bofh.it>
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Le 10/11/2017 à 17:46, Joe Pfeiffer a écrit :
> deloptes <deloptes@gmail.com> writes:
> 
>> you see in your case PARTUUID is different for both members. In my case it
>> is identical and this is what is bothering me
> 
> It's my understanding that PTUUID on a disk using an MBR corresponds to
> the UUID on a disk using a GPT, not to PARTUUID (I don't know what on an
> MBR-based disk would correspond to PARTUUID, if anything).

In the blkid syntax :
PTUUID = partition table UUID (in the partition table).
PARTUUID = partition UUID (in the partition table).
UUID = filesystem or other contents UUID (in the partition data).

There are no PTUUID nor PARTUUID in the MSDOS partition table format. 
There is only a 32-bit "disk identifier" field in the MBR, which can be 
displayed by fdisk. blkid uses it as a poor-man's PTUUID. Also, since 
version 3.8, the kernel combines the MSDOS disk identifier (PTUUID) and 
the partition numbers to create fake partition UUIDs (PARTUUIDs).

The GPT partition table format has real 128-bit independent PTUUID and 
PARTUUIDs.

Thread

Talking about RAID - disks with same id deloptes <deloptes@gmail.com> - 2017-11-08 22:50 +0100
  Re: Talking about RAID - disks with same id David Christensen <dpchrist@holgerdanske.com> - 2017-11-08 23:40 +0100
    Re: Talking about RAID - disks with same id deloptes <deloptes@gmail.com> - 2017-11-09 08:20 +0100
      Re: Talking about RAID - disks with same id David Christensen <dpchrist@holgerdanske.com> - 2017-11-09 19:20 +0100
        Re: Talking about RAID - disks with same id deloptes <deloptes@gmail.com> - 2017-11-09 22:10 +0100
          Re: Talking about RAID - disks with same id David Christensen <dpchrist@holgerdanske.com> - 2017-11-09 23:50 +0100
  Re: Talking about RAID - disks with same id Tobx <net@tobx.de> - 2017-11-09 10:40 +0100
    Re: Talking about RAID - disks with same id deloptes <deloptes@gmail.com> - 2017-11-09 22:20 +0100
  Re: Talking about RAID - disks with same id Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-11-10 00:00 +0100
    Re: Talking about RAID - disks with same id deloptes <deloptes@gmail.com> - 2017-11-10 09:20 +0100
      Re: Talking about RAID - disks with same id Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-11-10 18:10 +0100
        Re: Talking about RAID - disks with same id deloptes <deloptes@gmail.com> - 2017-11-10 20:50 +0100
        Re: Talking about RAID - disks with same id Pascal Hambourg <pascal@plouf.fr.eu.org> - 2017-11-12 17:20 +0100
      Re: Talking about RAID - disks with same id David Christensen <dpchrist@holgerdanske.com> - 2017-11-10 21:10 +0100
        Re: Talking about RAID - disks with same id deloptes <deloptes@gmail.com> - 2017-11-10 23:30 +0100
      Re: Talking about RAID - disks with same id Pascal Hambourg <pascal@plouf.fr.eu.org> - 2017-11-12 17:00 +0100
        Re: Talking about RAID - disks with same id deloptes <deloptes@gmail.com> - 2017-11-12 18:00 +0100
          Re: Talking about RAID - disks with same id Pascal Hambourg <pascal@plouf.fr.eu.org> - 2017-11-12 19:50 +0100
            Re: Talking about RAID - disks with same id deloptes <deloptes@gmail.com> - 2017-11-12 20:20 +0100

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