On Vi, 22 ian 21, 22:26:46, mick crane wrote:
hello,
I want to tidy things up as suggested.
Have one old PC that I'll put 2 disks in and tidy everything up so
what's
scattered about is on the running disks and this new/old one is just
backup
for them.
Can I assume that Debian installer in some expert mode will sort out
the
raid or do I need to install to one disk and then mirror it manually
before
invoking the raid thing ?
The "raid thing" is a separate layer below the partitions and file
systems.
Technically it is possible to create the mirror with just one device (I
believe mdadm calls this "degraded"), partition the md mirror device,
install, copy data to it, etc., add the second device later and let md
synchronize the two drives.
Because Linux RAID is a separate layer with no knowledge of the data
"above" it has to copy every single bit to the other drive as well
(similar to a dd device-to-device copy), regardless if actually needed
or not.
If you are really strapped for space and must do this ZFS can do it
much
more efficiently, because it controls the entire "stack" and knows
exactly which blocks to copy (besides many other advantages over Linux
RAID).
Unfortunately ZFS is slightly more complicated from the packaging side,
and installing Debian on a ZFS root is difficult.
It still makes an excelent choice to manage your storage drives,
especially on a stable system, where there is less hassle with the dkms
module and it's amazingly simple to use once you familiarise yourself
with the basics.
Kind regards,
Andrei