Strange Disk/data usage?

Now it's 8.04GB / 339MB :(

As suggested by trondn, some more detail numbers:

#items: 1377507,

RAM Usage/Quota: 246MB / 512MB

Within the bucket folder, there are 1032 files which are roughly same sized (6~10M), and most of them are touched frequently.

The version: 2.0.0-1723-rel (in mac)

Single node, w/ ops < 40

Have you tried to run "compaction" for your bucket?

I tried but it didn't help. Actually it completed too fast.

docs fragmentation % is 96%! but User-triggered compaction of that bucket is completed in less than 1 minutes, and doesn't reduce the fragmentation.

This error keeps happening in the log:
=ERROR REPORT==== 6-Nov-2012::22:02:05 ===
OS_MON (disksup) called by <0.4835.375>, not started
[error] [<0.4835.375>] {error_report,<0.62.0>,
{<0.4835.375>,crash_report,
[[{initial_call,
{compaction_daemon,
'-spawn_vbucket_compactor/2-fun-0-',[]}},
{pid,<0.4835.375>},
{registered_name,[]},
{error_info,
{error,
{badmatch,none},
[{compaction_daemon,free_space,1},
{compaction_daemon,ensure_can_db_compact,1},
{compaction_daemon,
'-spawn_vbucket_compactor/2-fun-0-',4},
{proc_lib,init_p,3}]}},
{ancestors,
[<0.4831.375>,<0.4817.375>,<0.4803.375>,
compaction_daemon,<0.21190.63>,ns_server_sup,
ns_server_cluster_sup,<0.63.0>]},
{messages,[]},
{links,[<0.4831.375>]},
{dictionary,[]},
{trap_exit,false},
{status,running},
{heap_size,610},
{stack_size,24},
{reductions,589}],
[]]}}

=CRASH REPORT==== 6-Nov-2012::22:02:05 ===
crasher:
initial call: compaction_daemon:-spawn_vbucket_compactor/2-fun-0-/0
pid: <0.4835.375>
registered_name: []
exception error: no match of right hand side value none
in function compaction_daemon:free_space/1
in call from compaction_daemon:ensure_can_db_compact/1
in call from compaction_daemon:'-spawn_vbucket_compactor/2-fun-0-'/4
ancestors: [<0.4831.375>,<0.4817.375>,<0.4803.375>,compaction_daemon,
<0.21190.63>,ns_server_sup,ns_server_cluster_sup,<0.63.0>]
messages: []
links: [<0.4831.375>]
dictionary: []
trap_exit: false
status: running
heap_size: 610
stack_size: 24
reductions: 589
neighbours:
[error] [<0.4859.375>] OS_MON (disksup) called by <0.4859.375>, not started