Question about FSHammer getting full

Thomas Nikolajsen thomas.nikolajsen at
Thu Aug 27 01:02:00 PDT 2009

>I got  a hammer FS running 59 days (today was 60, recopy is scheduled every 30,
>maybe a coincidence, maybe not)
>The thing is the Hd got full today, i destroyed some old PFSs to make some space (6GBS) and 5 minutes >after it was full again, im guessing something is filling it real fast, but dont know where to look at :-/
>It does mirror copy  from other mahcines every 30 minutes, but stopped that before remove the 6GB.
>Any ideas, suggestions?
>If i found it, and i stop it, is there a way to remove the full story from all snapshots of those specific files >consuming all?

You can only delete history in HAMMER filesystem per PFS, not per file.

When a HAMMER filesystem gets too full, do a prune and a reblock,
if that isn't enough delete some snapshots and do prune & reblock again.
This has to be done for each PFS, and base HAMMER filesystem (really PFS#0).
(or at least where you think history is taking up space)

This presumes that snapshots are made; if system is running continously,
periodic(8) will do daily snapshots (part of `hammer cleanup').
If no snapshots are made, you need to make one (per PFS),
as prune only deletes history after last snapshot.

hammer prune /HAMMER
hammer reblock /HAMMER 95

hammer prune /HAMMER/pfs/foo
hammer reblock /HAMMER/pfs/foo 95

hammer prune /HAMMER/pfs/bar
hammer reblock /HAMMER/pfs/bar 95

(or use more elaborate procedure, as `hammer cleanup':
hammer prune /HAMMER
hammer reblock-btree /HAMMER
hammer reblock-inodes /HAMMER
hammer reblock-dirs /HAMMER
hammer reblock-data /HAMMER

etc, for PFSs

See hammer(8) and HAMMER(5) (man hammer & man HAMMER) for more info.

(I have been planning to add a `hammer -X cleanup PFS now' (maybe other name)
to force an extra small (prune & reblock), medium (prune & recopy) or
full (prune & recopy without time limit) cleanup, without snapshot generation, for things like this;
also description like above one could go into an example in hammer(8))

Presently there is no tool to see space used for a given snapshot, or PFS,
this could be a nice feature.


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