Re: Converting system to raid

[Jeff Garzik <jeff@garzik.org>]

jim owens wrote:
> To continue the pointless (but maybe entertaining) argument :)
> 
> Jeff Garzik wrote:
>> jim owens wrote:
>>> The filesystem mod-time might have nanoseconds in it, but
>>> that does not mean 2 writes 100 nanoseconds apart will have
>>> different mod-times.
>>
>> Modern Linux filesystems absolutely do do metadata updates at that 
>> level of granularity.
> 
> In filesystems it only counts if it makes it to disk.
> 
> 10,000,000 write-to-disk metadata updates per second?  I think not.

Does every write (mtime update) trigger a write to disk?  I think not :) 
  You can write (== update inode mtime) 10,000,000 times, without ever 
touching disk.  Yet you fstat() still returns a nanosecond-granularity 
mtime.

	Jeff