HAMMER snapshot access from NFS client

Thomas Nikolajsen thomas.nikolajsen at mail.dk
Wed Nov 18 00:24:50 PST 2009

What is recommended setup for HAMMER snapshot access from NFS client?

It would be nice if we got a default setup, so it just worked out of the box.

With HAMMER version 3 we got easy default slave PFS snapshot location, nice.
But this moved dir with snapshots symlinks out of PFS (as needed for slave PFS),
which makes access from NFS client more convoluted.

Solution I can come up with is a bit convoluted:
NFS export /var/hammer, and make small script to convert snapshot symlink,
producing something like <NFS-client-PFS-mount>@@<tid>.

In HAMMER version 2-, I make symlinks with relative path names:
in snapshots/rel: ../../@@<tid>

Ahh this idea could be used on HAMMER version 3: e.g.:
client# mount -t nfs srv:/PFS /LOCAL
client# mount -t nfs srv:/var/hammer/HAMMER/PFS /LOCAL/snapshots
will give access to snapshots as /LOCAL/hammer/rel/snap-...
(rel/ could also be symlinked from /var/hammer/remote/LOCAL on client)
´snapshots´ could be another name if it collides with HAMMER version 2- use.
Generating the rel/ symlinks could be part of ´hammer cleanup´.

Any more straight forward ideas?


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