inscatolati - Get out of the box! :)

The whole message looks something like:

Setting up LVM Volume Groups... Reading all physical volumes. This may take a while...

followed by lot of kernel messages.

Well, that's the problem: lvscan, to find all the phyisical volumes, will just scan the first few sectors of every device on the system.

If you happen to have something particularly slow, lot of devices, or ... you are an aficionado of devfs (which will probe modules as pvscan tries to find those volumes), you will want to change /etc/lvm.conf.

Just add something like:

filter = [ "a|/dev/md*|", "a|/dev/sd*|" ]

in that file, to tell pvscan to search only in /dev/md* and /dev/sd*

Just:

• check how many extents you have available in the volume group

• use lvcreate with the -l option to specify the number of extents

   % vgs -o vg_name,vg_size,vg_free,vg_extent_count,vg_free_count
   VG     VSize  VFree #Ext  Free
   system 67.96G 8.96G 17397 2293
   % lvcreate -n backup -l 2293 system
   

Instead of using vgs, you can use vgdisplay, and use the field:

[...] Free PE / Size 2293 / 8.96 GB [...]

Just:

• check how many extents you have available in the volume group

• use lvcreate with the -l option to specify the number of extents

   % vgs -o vg_name,vg_size,vg_free,vg_extent_count,vg_free_count
   VG     VSize  VFree #Ext  Free
   system 67.96G 8.96G 17397 2293
   % lvcreate -n backup -l 2293 system
   

Instead of using vgs, you can use vgdisplay, and use the field:

[...] Free PE / Size 2293 / 8.96 GB [...]