I was reading about pvmove's ability to move extends from one PV to another (which would be useful, if for an example, a disk drive was starting to show signs of failures). man pages explain you can either move all of the extends on a particular PV or only a specific LV's extends:

or


Now, playing around in a pretend scenario where I'd only want to move a few select LVs for one reason or another (i.e: the only available PV doesn't have enough space to take all LVs from the failing PV and I'd like to move the most important LVs first) I tried finding out which PV a specific LV is on:

I tried all display and scan commands, each of them with -v, i.e.: lvdisplay, vgdisplay, pvdisplay, lvscan, vgscan and pvscan but nothing seems to specify which PV a specific lv is using.


Which brings two questions:

1. If a VG has multiple PVs assigned to it, how is it decided which PV is used when an LV is created?

2. How do I determine the PV being used for a specific LV? Of course, this question assumes there are multiple PVs assigned to the VG



TIA

With the lvdisplay and pvdisplay options you can use -v to get somewhat more verbose information. -vv to get even more vebose, -vvv to get yet more etc...

Thank you for your reply, unfortunately turning up the verbosity level with additional "v"s didn't help.

First check the whole information about the lvm

try all these command it may help you to understand.

pvdisplay -m (It gives the information about the disk, if disk is add in a vg then vgname also)

vgdisplay -vv (Number of disk add in the VG & how much PE is used from the each disk & how much PE free)

lvdisplay -M /dev/mapper/vg/lv (It gives the full information about the PV VG & LV of that particular lv)

#pvs (pv & vg name pvfree)

#vgs (pv & lv information vgfree)

#lvs (lv & vg lvmsize)