Re: Upgrading storage on bordeaux.guix.gnu.org

[Maxim Cournoyer]

Hello,

Ludovic Courtès <ludo@gnu.org> writes:

> Hello!
>
> (+Cc: Andreas.)
>
> Ricardo Wurmus <rekado@elephly.net> skribis:
>
>> [space is running out on bayfront, so I wrote:]
>>
>>> Remember that I’ve got three 256G SSDs here that I could send to
>>> wherever bayfront now sits.  With LVM or a RAID configuration these
>>> could just be added to the storage pool — if bayfront has
>>> sufficient slots for three more disks.
>>
>> You wrote in response:
>>
>>> Good to know.  In that case we’d need to come up with (1) an updated
>>> Guix System config with LVM, and (2) a way to copy the existing
>>> store
>>> over to the new storage, which sounds tricky if the existing disk is
>>> to
>>> be kept.
>>
>> We could first install Guix System with the adjusted bayfront config
>> on a separate machine (e.g. on a build node at the MDC), onto a volume
>> with LVM (using as many of the SSDs as needed). Copy signing keys etc
>> from bayfront.  Then we’d pretty much export/import the bayfront store
>> over the network.  Once everything has been copied, we turn off
>> bayfront, swap the disks, boot it up again.  If everything works all
>> right we add the original disk (and any unused left-over disks) to the
>> LVM volume to extend the storage pool.
>
> Sounds like a plan.  But note that there’s the store and there’s the
> cached nars, though maybe we can tolerate missing, say, a week or two of
> nars.

I don't know anything about the Bayfront machine specifics, but if it
was running with a Btrfs file system, it could be extendable live by
adding the new drives to it in Btrfs RAID0 configuration.

Cheers,

Maxim