Boot from gconcat volume?

[varda]

Anybody knows is it possible to reside root partition directly on gconcat volume?

For example I'm concatenating several mixed size drives 1TB and 1.5TB into single gconcat volume and then partitioning in some usual way to / /tmp /var /usr on that entire gconcat volume. Then manuallly installing system on created gconcat volume and prepare to load gconcat module at boot time.

But standard drive labeling take precedence against gconcat i.e. I see ad0a, ad0d and co on devices from first concatenated device which really created by step described above on gconcat volume. But gconcat'ed devices doesn't appears.

Certainly if create dedicated root partition and gconcat rest separate partitions everything goes all right as it thought.

So does this mean that it's not supposed by geom/gconcat architecture to boot from gconcat volume in the way like gmirror allowed to place root on gmirrored device and boot from it?

 

[fronclynne]

gconcat(8) is not a terribly good idea. If one drive dies your recovery options are nearly as limited as if you'd had a striped volume. If you really need the space blobbed up & zfs isn't an option, just use gconcat for the big filesystems (/usr/local/, /home/, /usr/src/, /usr/ports/).

I also don't think you actually gain anything by concatentating whole disks (as you do with zfs), so there's really no point in having / on a gconcat volume.

 

[varda]

Thanks for sharing your opinion, fronclynne.

I've asked for this purpose to know what others think, others experience and knowledge. In this case ZFS is too excessive for resources on low-power equipment. Also some backup option is assumed.

Anyway thanks for your reply. It helps to make a decision.