CentOS LVM expand root to extended partitions?

kenw232 · 02-11-2020, 02:35 PM

I am running out of space. So I created a new primary partition under Centos 7 and added it to my logical volume to expand /dev/mapper/centos-root. worked great.

Now I need to do it again, and will need to do it again in the future. But I already have 3 primary partitions. Therefore I need to make my forth partition an Extended partition right. Can I now add and use Linux LVM partitions called sda5 and sda6? is there any limit? I want to add space on demand without running out of partitions in the future.

eg. https://snipboard.io/86w3I1.jpg

kenw232 · 02-11-2020, 02:43 PM

how do I extend the extended partition? so I can add more Linux LVMs in the future when I want? If I expand the VM disk and do this:
Command (m for help): n
All primary partitions are in use
Adding logical partition 7
No free sectors available

I get "No free sectors available". but the disk has plenty of space free.

syg00 · 02-11-2020, 03:07 PM

Every time you expand the disk, all the new space will be outside the range of the extended partition - it (the extended) will need to be expanded to include all the new space before you can create new logical partitions. Can be done from fdisk, but you need to be careful - easier to use gparted if you have a GUI environment. This will give us a better view of your disk.

Code:

sudo parted /dev/sda "print free"

kenw232 · 02-11-2020, 04:23 PM

Is there a command line utility that can simply expand an extendated partition to the max size free? Seems excessive that I have to boot gparted to do that.

rknichols · 02-11-2020, 07:22 PM

It would be more straightforward to give the VM an additional disk rather than expanding the existing disk. Then you can add that unpartitioned disk to the volume group. Future expansions of that new disk would be simple (pvresize) since there are no partitions to deal with.