Re: guix on a cluster: install into existing mount

[Adam McCartney]

Can also offer a little bit of further clarification:

> + The recursively mounted subtrees don't survive a reboot, despite there being
>  fstab entries for them.
> + The guix daemon doesn't want to run, I think this maybe has something to do
>  with the way that the `gnu.mount` service is set up? I guess that unit is
>  maybe not expecting to find a mount under `/gnu/store`?

So, the typical pattern that was being applied when I approached the system was 
append the following two entries to fstab:

```
[HOST_IP]:/gpfs/opt/adm /mnt/adm nfs rw,async,noatime,nodiratime,_netdev 0 0
[HOST_IP]:/gpfs/opt/sw /mnt/sw nfs rw,async,noatime,nodiratime,_netdev 0 0
```

As I mentioned in the thread above, I've recreated the required guix folders
as:
 + `/mnt/sw/dev/guix/gnu/store`
 + `/mnt/sw/dev/guix/var/guix`
 + `/mnt/sw/dev/guix/var/log/guix`

And then used the recursive bind option for mount:

```
mount --rbind /mnt/sw/dev/guix/gnu/store/ /gnu/store
mount --rbind /mnt/sw/dev/guix/var/guix/ /var/guix
mount --rbind /mng/sw/dev/guix/var/log/guix/ /var/log/guix
```

At this point it's possible to start the guix daemon and do a guix pull.

I'm a bit unsure as to how to make these recursive bind mounts persistent in
fstab. I've tried a couple of different options:

As type nfs rbind
```
/mnt/sw/dev/guix/gnu/store /gnu/store nfs rbind
...
```

As type none rbind
```
/mnt/sw/dev/guix/gnu/store /gnu/store none rbind
...
```

Referencing the host directly
```
[HOST_IP]:/gpfs/sw/dev/guix/gnu/store /gnu/store nfs rbind
...
```

Any pointers in the direction of where I might find some more info on making 
recursive bind mounts persistent much appreciated!

cheers,
Adam

p.s. I have considered that a cleaner solution would be to actually export the 
relevant directories from the nfs server rather than creating bind mounts after
it has been mounted. This is probably an option going forward, but for the time
being I probably have to make do with the test setup as described above.



--
 Adam McCartney - https://admccartney.mur.at 
/