On 17 February 2013 21:12, Reindl Harald <h.reindl(a)thelounge.net> wrote:
Am 17.02.2013 22:03, schrieb Heinz Diehl:
> On 17.02.2013, Reindl Harald wrote:
>
>> if wouldn't do this and stick with dd / disk images and use gparted
>> to resize partitions because if i clone machines i want to have
>> all UUID's the same
>
> You can easily change/tailor your UUIDs with tools like tune2fs
have fun change also the RAID UUID's everywhere
and setup all identical because you have also
internal UUIDs on the RAID-partitions
[root@srv-rhsoft:~]$ cat /etc/mdadm.conf
MAILADDR root
AUTO +imsm +1.x -all
ARRAY /dev/md0 level=raid1 num-devices=4 UUID=1d691642:baed26df:1d197496:4fb00ff8
ARRAY /dev/md1 level=raid10 num-devices=4 UUID=b7475879:c95d9a47:c5043c02:0c5ae720
ARRAY /dev/md2 level=raid10 num-devices=4 UUID=ea253255:cb915401:f32794ad:ce0fe396
oh yeah and the tun2fs-output of /dev/md0 is
[root@srv-rhsoft:~]$ tune2fs -l /dev/md0 | grep UUID
Filesystem UUID: 1de836e4-e97c-43ee-b65c-400b0c29d3aa
again: have fun to reacreate this setup 1:1 after rsync to
new drives - i bet it would not work at the end - well it
may not interest you on your setups, mine are always two
identical machines which are synced daily
> The "dd" approach has a bunch of disadvantages, one of the biggest is
> misalignment if your new drive is a SSD or advanced format HDD
which misalignment?
if i switch to SSD some years later as soon as 4x2 TB are at a
normal price i will simply remove disk 1, insert a SSD, rebuild
RAID and after the rbuild the same for the other 3 drives
I don't have a solid reference for this, only hearsay, but dd as a way
to transfer filesystems or partitions to SSD probably interferes with
wear-levelling.
http://serverfault.com/questions/282555/zeroing-ssd-drives
http://www.wonkity.com/~wblock/docs/html/ssd.html
I guess RAID tools must now have some way to address this.
--
imalone
http://ibmalone.blogspot.co.uk