[CentOS] can't create large LVM, even though pvscan shows enough space left

Fri Feb 25 22:00:04 UTC 2011
Robert Heller <heller at deepsoft.com>

At Fri, 25 Feb 2011 23:18:43 +0200 CentOS mailing list <centos at centos.org> wrote:

> 
> On Fri, Feb 25, 2011 at 4:00 PM, Lamar Owen <lowen at pari.edu> wrote:
> > On Friday, February 25, 2011 08:15:34 am Rudi Ahlers wrote:
> >> [root at francois-pc ~]# lvcreate -L 500gig -n 500G freenas
> >>   Insufficient free extents (127999) in volume group freenas: 128000 required
> >
> >> How do I actually create a 500GB volume?
> >
> > try
> > lvcreate -l 127999 -n 500G freenas
> >
> > The default '500G' size is 12,800 extents, but you only have 12,799 extents free; which gets rounded *up* to 500G by the free space display.  And that's a lower-case 'L' option, not an upper-case 'I' option.
> > _______________________________________________
> 
> 
> 
> Cool, thanx for the explanation. Why is there one extend "missing", or
> no usable?

Overhead (LVM meta data needs to be stored someplace) and/or roundoff
error. It is not really a 500G partition, it is like a 499.99<mumble>G
partition, which is displayed as a 'human readable' 500G.

> 
> 

-- 
Robert Heller             -- 978-544-6933 / heller at deepsoft.com
Deepwoods Software        -- http://www.deepsoft.com/
()  ascii ribbon campaign -- against html e-mail
/\  www.asciiribbon.org   -- against proprietary attachments