ZFS: Unable to expand pool after increasing disk size in vmware - resize

Question

I have a Centos7 VM with ZFS on linux installed.
The VM has a disk /dev/sdb, that I've added to a pool named 'backup', and in this pool created a dataset.
Now, I wanted to increase the size of the disk in VMware, and then expand the size of the pool, but I'm not getting this to work.
I've tried 'zpool online -e backup sdb', but nothing changes.
I've tried running 'partprobe /dev/sdb' before and after the live above, but nothing changes.
I've tried rebooting + the above, nothing changes.
I've tried "parted /dev/sdb",resizing the partition (it suggests the actual new size of the volume), and then all of the above. But nothing changes
I've tried 'zpool export backup' + 'zpool import backup' in various combinations with all of the above. No luck
And also: 'lsblk' and 'df -h' reports the old/wrong size of /dev/sdb, even if parted seems to understand that it has been increased.
PS: autoexpand=on
What to do?

Answer 1

I faced a similar issue today and had to try a lot before finding the solution.
When I tried the known solutions (using zpool) of setting autoexpand as on and also restarting the partprobe, system would not auto expand (even after a restart).
Finally, I could solve it using parted instead of getting into zpool at all.
We need to be careful here since wrong partition selections can cause data loss.
What worked for me in your situation
Step 1: Find which pool you are trying to expand. In my case, it is 5 as seen below (unallocated space is after this pool). Use parted -l
parted -l
Output
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sda: 69.8GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 2097kB 1049kB bios_grub
2 2097kB 540MB 538MB fat32 EFI System Partition boot, esp
3 540MB 2009MB 1469MB swap
4 2009MB 3592MB 1583MB zfs
5 3592MB 32.2GB 28.6GB zfs
Step 2: Instructing explictly to expany pool number 5 to 100% available. Note that '5' is not static. You need to use the pool id you wish to expand. Double-check this. Use parted /dev/XXX resizepart YY 100%
parted /dev/sda resizepart 5 100%
After this, I was able to use the entire space in VM.
For reference:
LSBSK Before
sda 8:0 0 65G 0 disk
├─sda1 8:1 0 1M 0 part
├─sda2 8:2 0 513M 0 part /boot/grub
│ /boot/efi
├─sda3 8:3 0 1.4G 0 part
│ └─cryptoswap 253:1 0 1.4G 0 crypt [SWAP]
├─sda4 8:4 0 1.5G 0 part
└─sda5 8:5 0 29.5G 0 part
LSBSK After
sda 8:0 0 65G 0 disk
├─sda1 8:1 0 1M 0 part
├─sda2 8:2 0 513M 0 part /boot/grub
│ /boot/efi
├─sda3 8:3 0 1.4G 0 part
│ └─cryptoswap 253:1 0 1.4G 0 crypt [SWAP]
├─sda4 8:4 0 1.5G 0 part
└─sda5 8:5 0 61.7G 0 part