Strange case of deleting lots of files and "df" not recognizing it....(unless I umount/mount) the disk...

[Linda Walsh]

Ben Myers wrote:
> On Mon, Jun 25, 2012 at 09:02:11AM +0200, Emmanuel Florac wrote:
>> Le Sun, 24 Jun 2012 22:58:12 -0700 vous écriviez:
>>
>>> So when does it actually synchronize w/o me forcing it?  (I.e.
>>> umount/mount)?
>>>
>> Yes, it happens sometimes and a umount/mount is needed to fix it.
> 
> You may find that this will get the job done:
> echo 3 > /proc/sys/vm/drop_caches
> 
> -Ben
> 
Yup...it went away for a LONG time...maybe 30 seconds...

Does that mean there was that much unsynchronized data being held in memory
that wasn't being written out??

It DID fix the space allocation issue.

When I read the value before changing it, it said '0'.

when it finished, I tried to set it back to '0', but got an invalid argument.???
Was it really '2' or something else?


BTW -- it had been in the weird state for 13 hours before I issued the
order to drop_caches... seems like a long time not to cache data...?