Am 13.09.22 um 19:39 schrieb Wols Lists:
On 13/09/2022 12:12, Reindl Harald wrote:
"For example, you cannot create 3TB or 4TB partition size (RAID based)
using the fdisk command. It will not allow you to create a partition
that is greater than 2TB" makes me nervous
how to get a > 3 TB partition for /dev/md2
--------------------
and finally how would the command look for "Then with just two drives
you change the raid to raid-1"?
the first two drives are ordered to start with 1 out of 4 machines
ASAP given that the machine in front of me is running since 2011/06
365/24......
Dare I suggest you read the raid wiki site?
In particular
https://raid.wiki.kernel.org/index.php/Setting_up_a_(new)_system
https://raid.wiki.kernel.org/index.php/Converting_an_existing_system
Also a very good read ...
https://raid.wiki.kernel.org/index.php/System2020
Which is the system I'm typing this on.
These pages don't all jibe with what I remember writing, but read them
carefully, make sure you understand what is going on, and more
importantly WHY, and you should be good to go.
And when you're wondering how to go from the 4-drive raid-10 to the
2-drive raid-1, you should be able to just fail/remove the two small
drives and everything will migrate to your two new big drives, and then
it's just whatever the command is to convert between raid levels. The
drives will already be in a raid-1 layout, so converting from 10 to 1
will just be a change of metadata
if it's that easy why aren't mdadm doing it?
[root@testserver:~]$ mdadm /dev/md0 --grow --level=1
mdadm: RAID10 can only be changed to RAID0
virtual machine with two drives replaced against double sized