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Accepted
Gareth
Asked: 2013-06-07 05:30:09 +0800 CST

How do I remove a pool from ZFS?

  • 772

My Ubuntu 12.04 system has two zpools: rpool (containing the root filesystem) and rdata (containing all other data). rdata was originally 2 x 1TB disks mirrored.

Because I couldn't upgrade rdata to 3TB disks (wrong ashift) I had to create a new zpool from the new 3TB disks: initially called datapool. I then rsync'd all the data across, exported rdata, imported datapool as rdata and Bob's your Uncle. I then powered off and removed the old disks. However...

When I powered back on, zpool status shows

  pool: rdata
 state: UNAVAIL
status: One or more devices could not be used because the label is missing 
    or invalid.  There are insufficient replicas for the pool to continue
functioning.
action: Destroy and re-create the pool from
    a backup source.
   see: http://zfsonlinux.org/msg/ZFS-8000-5E
  scan: none requested
config:

NAME                                                 STATE     READ WRITE CKSUM
rdata                                                UNAVAIL      0     0     0         insufficient replicas
  mirror-0                                           UNAVAIL      0     0     0  insufficient replicas
    scsi-SATA_WDC_WD10EADS-00_WD-WCAU47275172-part1  UNAVAIL      0     0     0
    scsi-SATA_WDC_WD10EADS-00_WD-WCAU47283913-part1  UNAVAIL      0     0     0

  pool: rpool
 state: ONLINE
  scan: scrub repaired 0 in 0h23m with 0 errors on Tue Jun  4 11:33:29 2013
config:

NAME                                 STATE     READ WRITE CKSUM
rpool                                ONLINE       0     0     0
  ata-Maxtor_6Y120L0_Y31J3CLE-part2  ONLINE       0     0     0

errors: No known data errors

As you can see, zpool status is still showing the old rdata; which is not available.

zpool import shows

   pool: rdata
     id: 7033445233439275442
  state: ONLINE
 action: The pool can be imported using its name or numeric identifier.
 config:

rdata                                   ONLINE
  mirror-0                              ONLINE
    scsi-SATA_ST3000DM001-1CH_W1F1EE1G  ONLINE
    scsi-SATA_ST3000DM001-1CH_W1F25SE2  ONLINE

This is the correct rdata

Question: How do I get Ubuntu to forget all about the old zpool?

zfs

2 Answers

  1. Best Answer
    sudo zpool destroy rdata

    will destroy the old pool (you may need -f to force).

    sudo zpool export rdata

    will disconnect the pool.

    sudo zpool import 7033445233439275442

    will import the new pool. You need to use the id number as there are two "rdata" pools.

    As you're running with a ZFS root, all that's left to do is rebuild the initramfs to update the pools:

    sudo update-initramfs -c -k all
sudo update-grub

    Reboot and all is well. :)

    • 11

  2. You can destroy pool within just a command.

    sudo zpool destroy <poolname>

    Check the status of pool

    sudo zpool status <poolname>
    • -1