Cent OS 7 Re-partition of allocated disk

Question

I was trying to install SolusVM KVM slave on centos 7, the Datacenter provided me operating system having partition as I explained below, for installing KVM Slave I need PE Size 32MB from default size of 4MB. The whole disk in the pre-config server has been allocated and there is no free space left.

Is there any option using which I can change the PE from 4MB of default volume group vg to 32MB?

These are my system partition details:

Filesystem           Size  Used Avail Use% Mounted on
/dev/mapper/vg-root  2.7T  3.7G  2.6T   1% /
devtmpfs              12G     0   12G   0% /dev
tmpfs                 12G     0   12G   0% /dev/shm
tmpfs                 12G   50M   12G   1% /run
tmpfs                 12G     0   12G   0% /sys/fs/cgroup
/dev/mapper/vg-tmp   976M  2.8M  906M   1% /tmp
/dev/sda2            243M  166M   64M  73% /boot
tmpfs                2.4G     0  2.4G   0% /run/user/0

and volume groups as:

 --- Volume group ---
 VG Name               vg
 System ID
 Format                lvm2
 Metadata Areas        1
 Metadata Sequence No  4
 VG Access             read/write
 VG Status             resizable
 MAX LV                0
 Cur LV                3
 Open LV               3
 Max PV                0
 Cur PV                1
 Act PV                1
 VG Size               2.73 TiB
 PE Size               4.00 MiB
 Total PE              715333
 Alloc PE / Size       715317 / 2.73 TiB
 Free  PE / Size       16 / 64.00 MiB
 VG UUID               efYAtj-6gT5-42wf-7xyH-pQoD-Rxjf-xK5eaS

and fdisk -l as:

Disk /dev/sda: 3000.6 GB, 3000592982016 bytes, 5860533168 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: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1  4294967295  2147483647+  ee  GPT
Partition 1 does not start on physical sector boundary.

Disk /dev/mapper/vg-root: 2986.5 GB, 2986499637248 bytes, 5833007104 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/vg-swap: 12.7 GB, 12683575296 bytes, 24772608 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/vg-tmp: 1073 MB, 1073741824 bytes, 2097152 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

I also have the option of sysrcd 4.3.1 from the data center, If resizing is not possible from the current CentOS then can I do so using sysrcd 4.3.1 and how?

score 1 · Answer 1 · answered Jan 28 '18 at 10:50

If you would have done some research, you might find existing questions such as How important is PE Size for KVM virtualization? That was also in a VM host workload, it fact it also was SolusVM. The reason for doing so was the limit on LVM1 extents, which is not a limitation anymore with LVM2. 32MB is probably still a good size, but it may not be strictly necessary.

Also see How to change Volumegroup PE size? Basically, re-create the VG with the desired size.

I recommend asking for separate LUNs for data and creating additional volume groups. When your data is not on the OS VG it is possible to re-create the VGs as desired. It also is easier to swing the data to a different host, you can even change the OS distribution this way if they both can use LVM.

Cent OS 7 Re-partition of allocated disk

1 Answers1