From mboxrd@z Thu Jan  1 00:00:00 1970
From: erik quanstrom <quanstro@quanstro.net>
Date: Tue,  5 Mar 2013 01:22:06 -0500
To: 9fans@9fans.net
Message-ID: <41f95d8dba3fa0a675fbc54e151ba844@kw.quanstro.net>
In-Reply-To: <7E48F293-1D27-4958-BB64-BDDC490CB7E7@ar.aichi-u.ac.jp>
References: <7E48F293-1D27-4958-BB64-BDDC490CB7E7@ar.aichi-u.ac.jp>
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Subject: Re: [9fans] dirty blocks in cwfs
Topicbox-Message-UUID: 23913288-ead8-11e9-9d60-3106f5b1d025

On Tue Mar  5 01:03:23 EST 2013, arisawa@ar.aichi-u.ac.jp wrote:
> Hello,
>
> It seems my cwfs has too many dirty blocks.
> cfws command ("dump", "check tag" and etc) is no help to decrease these blocks.
> is this only to me?

i have not seen this with kenfs.  is it possible that you
are using the "t" bit that 9front added?  if so, that would
explain all the dirty blocks that never get dumped.
one also ends up with dirty superblocks that can't get
dumped because they're already written, about 1 per
day in the dump.

one thing i notice about your cache-worm is that the
cache is very large.  this is not advisable because your
cache buckets will take up too many memory buffers,
leaving little for actual data.  20G cache has been
enough.  the first big file server i set up had 750G
cache, and it thrashed the heck out of its disks.

- erik