[linux-lvm] "Condensing" Physical Volumes

[Lars Ellenberg]

On Sat, Dec 04, 2010 at 08:06:46PM +0200, David Baron wrote:
> I need more extents to move stuff off older, possibly failing IDE disks to my 
> new SATA terrabyter. However, not enough extents are available. The disk is 
> very sparsely populated.
> 
> Is there any way to "condense" physical volumes to recover/expose empty 
> extents in order to make use of them?

Does pvmove --alloc anywhere help?

Alternatively, you can specify exactly which extents go where,
like in "pvmove --test -n lvname.to.move /dev/pvold:20-27 /dev/pvnew:732-739".
obviously, remove --test, if it seems to do what you meant.

To see which what is where, and which extent ranges are free,
I tend to use variants of
pvs -o vg_name,lv_name,pv_name,pvseg_start,pvseg_size,seg_pe_ranges -Opv_name,pvseg_start
Note that pe_ranges are inclusive, (end of the range is: pvseg_start  + pvseg_size -1).

hth,

-- 
: Lars Ellenberg
: LINBIT | Your Way to High Availability
: DRBD/HA support and consulting http://www.linbit.com

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