HAMMER fs space problem

[Johannes Hofmann]

lhmwzy <lhmwzy at gmail.com> wrote:
> I mount a HAMMER file system called /www
> $df -h
> Filesystem    Size   Used  Avail Capacity  Mounted on
> /dev/da0s1a   252M    88M   144M    38%    /
> /dev/da0s1d   252M    25M   207M    11%    /var
> /dev/da0s1e   252M    14K   232M     0%    /tmp
> /dev/da0s1f   7.9G   2.1G   5.1G    30%    /usr
> /dev/da0s1g    29G   169M    26G     1%    /home
> procfs        4.0K   4.0K     0B   100%    /proc
> www            19G   0M    19G     0%    /www
> 
> 
> I create a php file which content is <? phpinfo(); ?>
> 
> Then after days,run df -h again:
> $df -h
> Filesystem    Size   Used  Avail Capacity  Mounted on
> /dev/da0s1a   252M    88M   144M    38%    /
> /dev/da0s1d   252M    25M   207M    11%    /var
> /dev/da0s1e   252M    14K   232M     0%    /tmp
> /dev/da0s1f   7.9G   2.1G   5.1G    30%    /usr
> /dev/da0s1g    29G   169M    26G     1%    /home
> procfs        4.0K   4.0K     0B   100%    /proc
> www            19G   8.0M    19G     0%    /www
> 
> I am not run a cron to reblock /www
> which file(s)  consume the 8m space?
> 
> Or run a cron like
>     15 2 * * * hammer -c /var/run/www -t 300 reblock /www >/dev/null 2>&1
> would make it better?
> 
> I run      15 2 * * * hammer -c /var/run/Home -t 300 reblock /home
>>/dev/null 2>&1 manually,
> 
> $hammer -c /var/run/www -t 300 reblock /www
> reblock free level 0
> Reblock /www succeeded
> Reblocked:
>    1/1 btree nodes
>    9/9 data elements
>    909/909 data bytes
> $df -h
> Filesystem    Size   Used  Avail Capacity  Mounted on
> /dev/da0s1a   252M    88M   144M    38%    /
> /dev/da0s1d   252M    25M   207M    11%    /var
> /dev/da0s1e   252M    14K   232M     0%    /tmp
> /dev/da0s1f   7.9G   2.1G   5.1G    30%    /usr
> /dev/da0s1g    29G   169M    26G     1%    /home
> procfs        4.0K   4.0K     0B   100%    /proc
> www            19G   8.0M    19G     0%    /www
> 
> the 8M space is not released.

HAMMER internally uses 8M blocks, so df will always show multiples
of 8M for used space.
However, if you create more files in /www, df used count should
stay at 8M until your files use up more than these 8M, at
which point it will probabely switch to 16M.

  Johannes

PS: I'm just another HAMMER user, so please correct me if I'm wrong.