What is the minimal memory requirement for HAMMER?

[Thomas Nikolajsen]

>I am trying to experiment with HAMMER with a spare PIII/500Mhz old
>machine with 256MB of RAM. I installed the RELEASE-2.10 version of
>DFBSD.  But when I try to execute "hammer cleanup", it spits out an
>error that reads:

>"hammer: System has insufficient buffers to rebalance the tree.  nbuf < 3969"

HAMMER(5), http://leaf.dragonflybsd.org/cgi/web-man?command=HAMMER&section=ANY
. .
DIAGNOSTICS
     hammer: System has insuffient buffers to rebalance the tree.  nbuf < %d
     Rebalancing a HAMMER PFS uses quite a bit of memory and can't be done on
     low memory systems.  It has been reported to fail on 512MB systems.
     Rebalancing isn't critical for HAMMER file system operation; it is done
     by hammer rebalance, often as part of hammer cleanup.
. .

(this man note was added after dfly-2.10, but applies there also)

I did use HAMMER on a 128MB system (w/ CPU like your system) (NFS server etc)
for a long time, which worked fine; this was until dfly-2.8; I am quite sure 256MB
is fine with current dfly (master), but didn't try recently.

See also issue1552 (http://bugs.dragonflybsd.org/issues/1552) (which introduced message)
for comments/pointers on low memory HAMMER use.

Hope this helps; do you experience HAMMER problems apart from this console message?

>Please throw some light! (Very dark here in Scandinavia during winters
>like this) ;-)

Here in southern Scandinavia (Denmark) we do have a bit of light, but I guess you are north :)

 -thomas