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Re: Talking about RAID - disks with same id




Le 10/11/2017 à 17:46, Joe Pfeiffer a écrit :
deloptes <deloptes@xxxxxxxxx> 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.