Resizing single disk pool

resize-single-disk-pool.md

1. Do kubectl exec inside the cstor-pool-mgmt using command and install parted

Get the pool pod name using kubectl get pods -n openebs command and exec inside the container. Install the parted tool using apt-get install parted after execing into the cstor-pool-mgmt container.

$ kubectl exec -it cstor-pool-1fth-7fbbdfc747-sh25t -n openebs -c cstor-pool-mgmt bash

2. zpool list (get the pool name)

$ zpool list
NAME                                         SIZE  ALLOC   FREE  EXPANDSZ   FRAG    CAP  DEDUP  HEALTH  ALTROOT
cstor-5be1d388-60d3-11e9-8e67-42010aa00fcf  9.94G   220K  9.94G         -     0%     0%  1.00x  ONLINE  -

3. Set your zpool with autoextend on (it defaults to off)

$ zpool set autoexpand=on cstor-5be1d388-60d3-11e9-8e67-42010aa00fcf`

4. Resize the disk used by the pool

If this is done already, that's fine.

5. Get the expanded device name that is in-use with pool using fdisk -l command and use parted /dev/<device-name> to lists partition layout on device. Just after this command, type Fix at prompt to use new available space.

$ parted /dev/sdb print

Warning: Not all of the space available to /dev/sdb appears to be used, you can
fix the GPT to use all of the space (an extra 20971520 blocks) or continue with
the current setting?
Fix/Ignore? Fix
Model: Google PersistentDisk (scsi)
Disk /dev/sdb: 21.5GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags:

Number  Start   End     Size    File system  Name                  Flags
 1      1049kB  10.7GB  10.7GB  zfs          zfs-d97901ec3aa0fb69
 9      10.7GB  10.7GB  8389kB

6. Remove the buffering partition

parted /dev/sdb rm 9

7. Expand partition holding zpool

$ parted /dev/sdb resizepart 1 100%

sh: 1: udevadm: not found
sh: 1: udevadm: not found
Information: You may need to update /etc/fstab.

8. Check the parted size again using parted /dev/<device-name> print

$ parted /dev/sdb print

Model: Google PersistentDisk (scsi)
Disk /dev/sdb: 21.5GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags:

Number  Start   End     Size    File system  Name                  Flags
 1      1049kB  21.5GB  21.5GB  zfs          zfs-d97901ec3aa0fb69

9. Size is changed from 10GB to 20GB, Now we have to tell the zpool to bring specified physical device online using following command.

Note: Replace the disk name below by get disk name using zpool status command.

zpool online -e cstor-5be1d388-60d3-11e9-8e67-42010aa00fcf /dev/disk/by-id/scsi-0Google_PersistentDisk_pdisk2

10. Restart the NDM pods schedeuled on same node with pool to reflect the updated size in Disk customresource

After restart make sure NDM pod comes in Running state.