[Ocfs2-users] Some questions about ocfs2

[Sunil Mushran]

What's the blocksize?

Ulf Zimmermann wrote:
>> -----Original Message-----
>> From: Sunil Mushran [mailto:Sunil.Mushran at oracle.com]
>> Sent: 04/25/2007 10:31
>> To: Ulf Zimmermann
>> Cc: ocfs2-users at oss.oracle.com
>> Subject: Re: [Ocfs2-users] Some questions about ocfs2
>>
>> # debugfs.ocfs2 -R "stats -h" /dev/sdy2 | grep "Cluster Size"
>>         Block Size Bits: 12   Cluster Size Bits: 17
>> 12 = 4K
>> 17 = 128K
>>
>> Have you tried stracing the process?
>> # strace -tt -T  -o /tmp/strace.out  ...
>>     
>
> Yes, strace shows shows most time is spent in lstat64 (> 99%), where
> average execution time on ext3 is < 60 usecs/call while on the ocfs2
> volume it is > 500 usecs/call.
>
>   
>> Ulf Zimmermann wrote:
>>     
>>> Is there a way to see how a file system was formatted, i.e. the
>>>       
> block
>   
>>> size and cluster size? I currently have a 2TB file system, of which
>>> about 840GB are in use by around 9 million image files. Average size
>>>       
> of
>   
>>> these images is 60-100KB. Currently our production servers still
>>>       
> have
>   
>>> separate file systems on ext3 and we are doing nightly rsync from
>>>       
> there
>   
>>> to this ocfs2 volume. This currently takes ~6 hours, which seems a
>>>       
> tad
>   
>>> slow. The system spends most time during writing files which have
>>> changed on the production servers, with high I/O wait.
>>>
>>> The SAN this ocfs2 volume is on is pretty much idle, I only see up
>>>       
> to
>   
>>> about 20MB/sec traffic and the two nodes which have this volume
>>>       
> mounted
>   
>>> have a private GigE interconnect setup for cluster.conf.
>>>
>>> Any tips on how to debug where this slowness comes from? Or even
>>> suggestion to use another cluster file system for a scenario like
>>>       
> this.
>   
>>> Regards, Ulf.
>>>       
>
>
> Regards, Ulf.
>
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