Procedure? Move existing Wheezy from sda2 to md1
List, good afternoon,
I am proposing to reconfigure a newly-built server and introduce 2 x
3TB drives in a raid1 configuration. Wheezy is already installed on a
single 250GB drive, /dev/sda2. The 3TB raid1 will be exposed as a
logical volume, which I will then need to grow.
Because the machine has only 4 sata ports, and shortly I want to
introduce another 2 x 3TB drive pair to grow the LV, I'd like to move
the existing Wheezy install onto the 3TB raid1.
I propose to follow these steps, and I'd appreciate any suggestions if
I seem to be doing something silly.
1. First insert the 2 3TB drives and, using the existing Wheezy,
create a raid1 array. I would create three md arrays:
md0 for Grub, 100 MB
md1 for Wheezy, 250 GB
md2 for the LV filesystem, approx 2.75 TB.
2. At this point I can create my 2.75TB, and continue to use the
server, if we need to.
3. The Debian installer created several partitions for the Wheezy
install and, in my plan, I do not have those partitions replicated in
the raid1 system. So, moving (or copying, perhaps, is a better word)
Wheezy to /dev/md1 poses a little more difficulty. Though I would
have used DD if it were simply a matter of copying from one whole disk
to another, this time I need to copy the whole of '/' (which is
mounted on several partitions), while retaining all the metadata, etc.
I think I would need to
(a) create a filesystem on md1, and then
(b) use cp, perhaps, as root, to copy the whole of / (excluding any
nfs mount points). I've previously used the '-a' option with cp to
ensure that metadata is retained.
But I worry this won't work because /usr (for example) is a separate
mount point in fstab and I'll have to remove those (because the whole
of / would now be on a single partition), but I'm not sure if fstab
would be the only thing that needed to change.
4. Finally, I'd need to create a new Grub system; I haven't researched
that yet and will start by reading the grub documents. Its 'OS
detection' might help at that point, if the Wheezy install has been
successfully copied across to md1. I expect to install Grub on both
of the physical drives comprising the 3TB array. (Previous advice to
me, here
[🔎] u1igpaxm7c.ln2@news.roaima.co.uk">http://lists.debian.org/[🔎] u1igpaxm7c.ln2@news.roaima.co.uk
suggested this).
I'd be grateful for any comments on my approach, especially if there
is something I might have overlooked. In the meantime, I'm going to
partition the new 3TB drive pair:
100MB - for Grub booting
250GB - for Wheezy
2.75TB - for the server's LVM
and create raid1 arrays for each of these.
Ron
Reply to: