Re: different oops

Andrea Gelmini
2008-10-07T15:04:09Z

2008/10/7 Chris Mason <chris.mason@oracle.com>:
> Btrfs does use more cpu than reiserfs will because of the checksumming,
I don''t think this is the problem. I mean, in same condition, with
Reiserfs3,
I stay between 0.85 - 1.50 load avg.
Now I easily go from 5 - 10.
It''s hard to believe so much overhead just for CRC.
Anyway, can I safely mount my /home disabling CRC? I read it about time before.

> and you have dm-crypt using CPU as well.  Is the system unresponsive
> during the high load?
not exactly. it became slugghish. so, things that was zero-wait, now
may have seconds of delay.
something similar a "make -j"...
now I have doubled the space of the logical volume, and things seems
better (now, loadavg is not going over 4, doing
the mirrordir test).
anyway, I have to use it almost one day, to have a clear idea.

> The load on linux is somewhat strange because it reflects both the
> number of procs waiting on IO and the number using CPU.  Running top and
> looking at the process states will help figure out which one is the
> cause ''D'' means IO and ''R'' means CPU.
yes.
well, the strange things is the system is faster than before doing
write. but looking at top (I use htop, but it doesn''t matter), it
doesn''t seem something process related, but seems kernel alway busy
doing something I can''t figure out.

are there some tests I can run just to have some raw number to try to
explain this?

thanks a lot for your time,
Gelma