Re: [gentoo-amd64] Quick rsync backup before changing a RAID

[Mark Knecht]

On Wed, Jun 19, 2013 at 1:20 PM, Rich Freeman <rich0@g.o> wrote:
> On Wed, Jun 19, 2013 at 3:21 PM, Mark Knecht <markknecht@×××××.com> wrote:
>>
>> Is 'using ACLs' one of those things that if you don't know then you
>> are not? I just run basic Gentoo here. All installs done as per the
>> install guide. I don't even use LVM or anything fancy. (Which is
>> likely part of why I'm having to reconfigure as much as I am but so be
>> it.)
>
> Gentoo can potentially make use of them if you're using POSIX
> capabilities, but I think that has to be enabled by USE flag or
> FEATURE.  I think you might also have to enable them in fstab (and the
> kernel as well, though that is likely enabled by default).  Chances
> are you'd know if you were using them, and it would only apply to
> stuff installed by portage (generally binaries).  Oh, and using POSIX
> capabilities is a good thing (less suid root binaries).
>
> One thing to mention - I'm not sure how much data you're talking
> about, but if it is a lot and downtime is a concern you could probably
> get creative and avoid some copying.  You could copy the files onto an
> LVM vg, and then after your RAID is set up you could move the logical
> volume onto your RAID, which is an online operation.  (Ie set up your
> USB drive as LVM, copy the files over, adjust your mounts so that the
> USB drive is mounted where you want the files, and at this point
> they're in production.  Then get your RAID set up, add it to the
> volume group, and pvmove the USB drive so that it gets moved to your
> RAID.  Then remove the USB drive from your volume group and you're in
> the final config, with no further need to adjust mountpoints since
> they're already pointed to LVM.)  I've done a lot of messing around
> with online migrations of RAID and LVM - quite handy when you have
> lots of stuff like mythtv recordings that you don't want to have
> offline backups of.
>
> Rich
>

Interesting info Rich. Thanks.

Approximately 250GB involved. Not worried about downtime. The data is
all Windows VMs which I use for stock & futures trading. Only need the
machine back up by tomorrow morning.

Also, I've never used LVM so for an afternoon project it's unlikely
I'd be successful going that direction I think. The second USB backup
drive is about 50% done so I should be able to start working on
reconfiguring the RAID in about an hour and hopefully be back up and
running by 5PM if things go well.

Cheers,
Mark