Re: Stressing GC

[Reinoud Zandijk <reinoud-S783fYmB3Ccdnm+yROfE0A@public.gmane.org>]

Dear folks,

On Thu, Jun 11, 2009 at 11:39:50AM -0400, Luis Useche wrote:
> On Thu, Jun 11, 2009 at 08:17:51AM +0400, Dave wrote:
> > On 06/11/09 01:08, Luis Useche wrote:
> > > I was doing some experiments on nilfs2 to stress the garbage collection
> > > with different file system usage. Unfortunately, it was unable to pass the
> > > first test since nilfs reports no space available eventhough there are no
> > > files in the file system! I guess the GC is not collecting space fast
> > > enough and the file system ends up with no space available.
> > > 
> > > Do you have any workaround to this problem?
>
> With the current GC implementation, I am unable to do my experiment. I set
> "protection_period 0" but still have the problem. Besides, this is
> probably not the right solution either since the GC can do unnecessary work
> that can underestimate the potential of nilfs. I need the first option (1)
> from the first paragraph above.
> 
> Are there any workaround I can use to make this work.

idealiter there should be an analog to VMS's purge command, say purge_nilfs or
`nilfs purge /mnt' that flushes all data not protected by a snapshot or the
last checkpoint.

Could this be something?

Another more blunt method is say newfs'ing a disc, create a snapshot sometime,
mess around with it and later revert back to the snapshot.

With regards,
Reinoud