On 16 Jun 2015 12:12, "Always Learning" centos@u64.u22.net wrote:
On Tue, 2015-06-16 at 11:30 +0100, John Hodrien wrote:
On Tue, 16 Jun 2015, Always Learning wrote:
ON Centos 5, using GPARTED I created partitions for filing systems
ext3
and ext4. 4 primary and unlimited (except by space) extended
partitions.
That suggests those partitions are not GPT but old fashioned M$DOS
If it is old fashioned MSDOS, you can have four total primary and
extended,
not four primary plus extended. An extended partition then provides a container for further logical partitions.
Yes you are correct. Maximum 4 primary or maximum 3 primary and 1 extended which is then sub-divided into more partitions.
LUKS provides a UUID, so being encrypted isn't a barrier to having a
UUID.
But my point was M$ DOS partitions, not being GPT partitions, can have UUIDs. The original poster appeared to suggest that was not possible. He wrote
Those were filesystem UUIDs not partition UUIDs ...
LUKS has its own header similar to ext4, lvm, etc headers which has a UUID in it.
This UUID being associated with the LUKS header indicates it is not a partition UUID.
A dd of this (or lvm snapshot) to another partition will keep the same UUID.
A partition UUID within a GPT table would not be persisted in this manner, and msdos labeled disks have no concept of this to begin with.
Non-GPT partitions do not have a UUID. The _content_ (filesystem, LVM physical volume, non-encrypted swap space, etc.) of such a partition could have a UUID, but the partition itself does not.
When I think I am mounting a M$ DOS partition, am I mounting a real partition or merely 'the file system' within that partition ? Some may think one can't have one without the other.
Of course you can have a partition or filesystem without the other. This is how raw devices work and you can mkfs a block device with no partitions.
When you mount something you mount the filesystem.