Am 13.09.22 um 21:44 schrieb Wol:
On 13/09/2022 19:03, Reindl Harald wrote:
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
Hmm...
I don't know. I'll have to defer to the experts, but a raid-10 across
two drives has to be a plain mirror in order to provide redundancy.
So I don't know why it doesn't just change the array definition, because
the on-disk layout *should* be the same ...
not really - RAID 10 have stripes and it likely ends in having the data
on both disk at different places
