<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body bgcolor="#ffffff" text="#000000"> On 02/04/2011 03:37 AM, John Haxby wrote: <blockquote cite="mid:AANLkTimmDVfcJzwpn7cgDVjJiYum6icHRox2R8dnW65a@mail.gmail.com" type="cite"> <div class="gmail_quote">On 4 February 2011 08:50, carlopmart <<a moz-do-not-send="true" href="mailto:carlopmart@gmail.com">carlopmart@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> Hi all, Is it possible to create sparse block devices with LVM (logical volumes not volume groups) on RHEL6 like ZFS does?? </blockquote> <div> Do you mean something like this (from the lvcreate man page): "lvcreate --virtualsize 1T --size 100M --snapshot --name sparse vg1" creates a sparse device named /dev/vg1/sparse of size 1TB with space for just under 100MB of actual data on it. </div> </div> </blockquote> Ok. Cool feature from a technical perspective....But...What is the use case? I'm trying to wrap my head over why I would want to overcommit a logical volume's usable storage. I'm assuming there is some use case where it makes sense, but I'm not seeing it. The closest I can come is that you might manually resize the lv's 'real' size if you ever got close to filling it up. Enlighten me? -- Benjamin Franz </body> </html>