[SOLVED] How can I mount new disk and enlarge LV?

scott80109 · 02-27-2018, 01:02 AM

We're running out of disk space on centos-root, and I want to enlarge the partition. This is a remote Centos 7 server halfway across the country, so I can't use anything like GParted.

Here's the `df -H` output...

Code:

Filesystem         Size  Used Avail Use% Mounted on
/dev/mapper/centos-root   54G   22G   32G  41% /
/dev/sda1                518M  334M  185M  65% /boot
/dev/mapper/centos-home   78G  104M   78G   1% /home

Here's the `fdisk -l` output...

Code:

Disk /dev/sda: 322.1 GB, 322122547200 bytes, 629145600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: dos
Disk identifier: 0x0007be79

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     1026047      512000   83  Linux
/dev/sda2         1026048   266338303   132656128   8e  Linux LVM

Disk /dev/sdb: 136.4 GB, 136365211648 bytes, 266338304 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/mapper/centos-root: 53.8 GB, 53754200064 bytes, 104988672 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/mapper/centos-swap: 4160 MB, 4160749568 bytes, 8126464 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/mapper/centos-home: 77.9 GB, 77921779712 bytes, 152190976 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes

And finally, the `lsblk` command...

Code:

NAME            MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
fd0               2:0    1     4K  0 disk 
sda               8:0    0   300G  0 disk 
├─sda1            8:1    0   500M  0 part /boot
└─sda2            8:2    0 126.5G  0 part 
  ├─centos-root 253:0    0  50.1G  0 lvm  /
  ├─centos-swap 253:1    0   3.9G  0 lvm  [SWAP]
  └─centos-home 253:2    0  72.6G  0 lvm  /home
sdb               8:16   0   127G  0 disk 
sr0              11:0    1  1024M  0 rom

So a couple of things of note here:

1) The /dev/sda disk shows that it is 322.1 GB, yet the sda1 and sda2 partitions only combine to take up 127 GB. Where the heck is that other 195 GB, and what is it doing? How do I add it to the sda2 PV?

2) The /dev/sdb disk is apparently a new and unmounted disk. I would like to combine that 127 GB with the unused 195 GB on sda, and add that to centos-root.

Is this possible, and if so, how do I do it? I've searched all day for tutorials, but can't seem to find what I need. I'm not new to Linux, but I've never dealt with disks and partitions before. So specific details would be greatly appreciated!

scott80109 · 02-27-2018, 01:47 AM

I just found this excellent tutorial that solved all of my problems. I went through it twice. Once to format the unused /dev/sda space as an LVM partition and add it to the logical volume. And a second time to format the new /dev/sdb disk, and add it to the logical volume.

My centos-root disk space went from 54 GB to 376 GB!

https://www.rootusers.com/how-to-inc...-machine-disk/