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Re: Problem identified: WAPL/RAIDframe performance problems

Edgar Fuß <> writes:

>> I seem to be facing two problems:
>> 1. A certain svn update command is ridicously slow on my to-be file server.
>> 2. During the svn update, the machine partially locks up and fails to 
>> respond 
>>    to NFS requests.
> Thanks to very kind help by hannken@, I now at least know what the problem is.
> Short form: WAPBL is currently completely unusable on RAIDframe (I always 
> suspected something like that), at least on non-Level 0 sets.
> The problem turned out to be wapbl_flush() writing non-fsbsize chunks on non-
> fsbsize boundaries. So RAIDframe is nearly sure to RMW.
> That makes the log being written to disc at about 1MB/s with the write lock 
> on the log being held. So everything else on that fs tstiles on the log's 
> read lock.

Do you see this on RAID-1 too?

I wonder if it's possible (easily) to make the log only use fsbize
boundaries, (maybe forcing it to be bigger as a side effect.)

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