Hi, all --
I think that this has been asked before, and so I think that I know
where I'm
going, but before I take aim at my foot with a large-caliber mdadm ...
:-)
I have an existing
diskfarm:~ # parted /dev/sda unit MiB print free
Model: ATA SanDisk SD6SB1M1 (scsi)
Disk /dev/sda: 122104MiB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: pmbr_boot
Number Start End Size File system Name
Flags
0.02MiB 1.00MiB 0.98MiB Free Space
1 1.00MiB 33793MiB 33792MiB linux-swap(v1) diskfarm-swap
swap
2 33793MiB 66561MiB 32768MiB xfs diskfarmsuse
3 66561MiB 99329MiB 32768MiB diskfarmknop
legacy_boot
4 99329MiB 122104MiB 22775MiB xfs diskfarm-ssd
128G SSD. I have obtained a shiny new
diskfarm:~ # parted /dev/sde unit MiB print free
Model: ATA SATA SSD (scsi)
Disk /dev/sde: 244198MiB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name
Flags
0.02MiB 1.00MiB 0.98MiB Free Space
1 1.00MiB 33793MiB 33792MiB diskfarm-swap
swap
2 33793MiB 66561MiB 32768MiB diskfarmsuse
3 66561MiB 99329MiB 32768MiB diskfarmknop
legacy_boot
4 99329MiB 122104MiB 22775MiB diskfarm-ssd
122104MiB 244198MiB 122094MiB Free Space
256G SSD to use as a mirror. [You can ignore the sgdisk-copied
partition
layout for the moment; that was a false start.] My final-view plan is,
in
fact, to replace the 128 with another 256 and grow the -ssd data
partition.
For a typical mirror-an-existing, I think that I need to create all of
my
slices and the [degraded] mirror on the new, copy over the old, boot
from new,
and then treat old as just another disk to shove in. There's the
question of
making partitions larger for the RAID superblock info, though, and --
and
here's where I get confused -- even on the old disk when adding it in.
As you can see, I have no free space on the little guy. I was thinking
I'd
bump my slices larger on the new disk so that I have room to spare to
copy
everything over, with the data slice a little less larger than it would
have
been, but then ... I think I saw that I need to make the 2nd-drive
slices
larger, too, so what do I do with the old guy?
And, in fact, does it even matter? If I understand this correctly, I'll
be
running entirely from the new disk in the mirror once this is done, and
so it
doesn't matter whether I put the little old or the other big new in to
fill out
the mirror. If that's the case, then I don't really care about
partition size
because I'm going to start with mirrored partitions.
Oh, and just because I'm a glutton for punishment (even more than using
this
stupid webmail because we're currently down my home directory disk on
our mail
server and I'm impatient), if I'm essentially starting from scratch,
should I
mirror the entire [yes, identical] drive and partition the metadevice,
*BSD-style, or mirror individual partitions?
Thanks as always!
:-D
--
David T-G
See http://justpickone.org/davidtg/email/
See http://justpickone.org/davidtg/tofu.txt
