Andreas Ericsson wrote:
>>>
>>>
>>
>> I tried a program which I meant to attach to this mail that I deleted
>> by mistake as I was composing this mail, that fopen'd a file, wrote a
>> character at a time and either fclosed at the end, or fsync'd after
>> each character, or sync'd after each character. it wrote 1MB worth of
>> characters to the file.
>>
>
> Ahmm... That's not really such a great test, tbh. Try the write throughput
> with a testing tool for it and then divide the size of the file to be
> synced with the actual write speed of the disk and you'll get something
> rather close to the cost of a single fsync call for a particular file.
>
ah okay, thanks for the reply, I enjoy reading replies from experienced
folk, I learn from them.
>>
>> not sure how useful this really is to get an idea, but sync is clearly
>> to be avoided as you mentioned. what do you guys make of the
>> difference between fsync and no fsync in relation to nagios?
>>
>
> fsync() isn't needed when using a sane file system. When using an insane
> one, there are no guarantees that fsync() works anyway, so why use it?
>
it's not needed on a sane filesystem because another process trying to
read a file not completely sync'd will still see the latest content?
agree about the NFS issue, read a little about it's problems, and if
fsync isn't going to solve its problems, I see your point about not
using it.
if I'm not mistaken this patch was committed already? was there a reason
it was so easily accepted?
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