[SOLVED] LVM2 management

FrizzledOldButt · 01-31-2020, 08:45 PM

Hi
Hopefully someone can clear my befuddled and foggy grey matter:

Running Ubuntu server 64bit 18.04 LTS with an LVM array on an HP Proliant NAS:

sudo lvdisplay
--- Logical volume ---
LV Path /dev/vgpool/logical_vol1
LV Name logical_vol1
VG Name vgpool
LV UUID BOWg21-9MFT-Mq1z-xheE-nHiE-G7ip-Mw7FrP
LV Write Access read/write
LV Creation host, time proliant, 2019-09-09 12:52:11 +0930
LV Status available
# open 1
LV Size 10.46 TiB
Current LE 2742352
Segments 4
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0

PV VG Fmt Attr PSize PFree
/dev/sdb1 vgpool lvm2 a-- 1.36t 0
/dev/sdc1 vgpool lvm2 a-- <1.82t 0
/dev/sdd1 vgpool lvm2 a-- <3.64t 0
/dev/sde1 vgpool lvm2 a-- <3.64t 0

PFree is being reported as zero. However, I know that at most there is only about 5T stored on the LVM array.

How can I check that all available HDD space has been allocated to the array?

NB: IIRC when I set it up a year or two ago I allocated 100%FREE for every device.

Thanks

berndbausch · 01-31-2020, 08:53 PM

Quote:

Originally Posted by FrizzledOldButt

LV Size 10.46 TiB
...
PV VG Fmt Attr PSize PFree
/dev/sdb1 vgpool lvm2 a-- 1.36t 0
/dev/sdc1 vgpool lvm2 a-- <1.82t 0
/dev/sdd1 vgpool lvm2 a-- <3.64t 0
/dev/sde1 vgpool lvm2 a-- <3.64t 0

The LV size of 10.46 TB seems to be reasonably close to the sum of the PVs. I.e. the PVs are used up by this LV. PVs don't care what's used or free on the LV. Likewise, the LV doesn't care what's used on the filesystem that you may have created on top of it.

syg00 · 01-31-2020, 09:40 PM

Mount the lv - it probably does by default at boot - then run this from a terminal.

Code:

df -hT

FrizzledOldButt · 01-31-2020, 10:19 PM

Quote:

Originally Posted by syg00

Mount the lv - it probably does by default at boot - then run this from a terminal.

Code:

df -hT

Thanks for that. Now my confusion is complete:

Checking the logical volume, which if I understand correctly, is what the OS "sees",

Code:

sudo lvs 
  LV           VG     Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  logical_vol1 vgpool -wi-ao---- 10.46t

Is it correct that 10.46T should now be available at the mount point?

The above is now mounted at /mnt/lvm01 - checking the disk free space just 1.4T is reportedL

Code:

df -hT 
/dev/mapper/vgpool-logical_vol1 ext4      1.4T  476G  829G  37% /mnt/lvm01

the size 1.4T is the size of the first HDD in the array.

Cheers

berndbausch · 01-31-2020, 11:32 PM

The logical volume has a size of 10TB. The filesystem on it has a size of 1.4TB. Perhaps the LV was originally only on the first PV, but has been extended since. The filesystem was then not extended.

If you want that filesystem to occupy the entire 10TB, try

Code:

resize2fs /dev/vgpool/logical_vol1

FrizzledOldButt · 01-31-2020, 11:55 PM

Quote:

Originally Posted by berndbausch

The logical volume has a size of 10TB. The filesystem on it has a size of 1.4TB. Perhaps the LV was originally only on the first PV, but has been extended since. The filesystem was then not extended.

If you want that filesystem to occupy the entire 10TB, try

Code:

resize2fs /dev/vgpool/logical_vol1

OK, much obliged, although I had to run e2fsck first. Clearly when I replaced a HDD about 12 months ago I missed a step. Here's what I did just now:

Code:

sudo fsck -f /dev/vgpool/logical_vol1
sudo resize2fs /dev/vgpool/logical_vol1
sudo mount -a
df -h  /mnt/lvm01
/dev/mapper/vgpool-logical_vol1   11T  476G  9.4T   5% /mnt/lvm01

The total space is now reported as ~11T.

Many thanks for the help, guys.

Cheers