I am getting older, so here is a spot for lvm, forgot how to remember stuff:
What physical (or raid) device(s) is / are the lvm associated with?
# pvs PV VG Fmt Attr PSize PFree /dev/md2 vg0 lvm2 a- 1.77t 372.53g
So that would be vg0 on md device 2
Check cat /proc/mdstat for the physical disks in the md raid
If you want to see where it goes from there:
# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT vda 253:0 0 100G 0 disk ├─vda1 253:1 0 96G 0 part / ├─vda2 253:2 0 1K 0 part └─vda5 253:5 0 4G 0 part [SWAP] sr0 11:0 1 1024M 0 rom
Whats a whozit volume group of the logical volume thingie?
# vgdisplay --- Volume group --- VG Name vg0 System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 2 VG Access read/write VG Status resizable MAX LV 0 Cur LV 1 Open LV 1 Max PV 0 Cur PV 1 Act PV 1 VG Size 1.77 TiB PE Size 4.00 MiB Total PE 462726 Alloc PE / Size 367358 / 1.40 TiB Free PE / Size 95368 / 372.53 GiB VG UUID Mwa-ha-ha # lvdisplay --- Logical volume --- LV Name /dev/vg0/lv0 VG Name vg0 LV UUID Tra-La-La-UuId LV Write Access read/write LV Status available # open 1 LV Size 1.40 TiB Current LE 367358 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 252:0
So that would be volume group vg0 with the logical volume lv0 carved out of it
And look ma, extra physical extents. Can someone say snapshot?
Shrink it (WARNING- BACKUP FIRST AS YOU WILL PROBABLY LOOSE EVERYTHING)
e2fsck -f /dev/mapper/lvmtoshrink-part resize2fs /dev/mapper/lvmtoshrink-part XXXG (reduce underlying fs - ext2-4) lvreduce -L XXX+(something)G /dev/mapper/lvmtoshrink-part You can re-run resize2fs again without params to get it to expand to the logical volume by skipping the size, but I like having wiggle room for snapshots.