[CentOS] Size of /var/log/lastlog

[Matt Hyclak]

On Sun, Nov 06, 2005 at 04:16:21PM -0500, Sam Drinkard enlightened us:
> > Hi,
> > Can any of you explain this weirdness:
> > 
> > [root at machine log]# cd /var/log/
> > [root at machine log]# ls -la|grep last
> > -r--------   1 root  root  1254130450140 Nov  6 21:44 lastlog
> > [root at machine log]# du -hs lastlog
> > 52K     lastlog
> > 
> > What's up with the output of ls? This is x86_64.
> > 
> > Thanks,
> > 
> > Morten
> > 
> > 
> 
> There was a thread about this some time back.. you can safely delete the
> file, then touch the filename and all will be well.  There also was, I
> believe, a bugzilla about it somewhere upstream.
> 

There have been a couple. The deal is that lastlog is a sparse file that is
indexed by UID. On an x86_64 system, UIDs are 32-bit, which means a 1.2TB
file, but because it's sparse, it doesn't actually take up any disk space. 

There is some explanation here:

https://www.redhat.com/archives/fedora-test-list/2005-June/msg00308.html

Or you can search bugzilla for lastlog.

Matt

-- 
Matt Hyclak
Department of Mathematics 
Department of Social Work
Ohio University
(740) 593-1263