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Managing ZFS File Systems in Oracle® Solaris 11.4

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Updated: August 2019

Handling ZFS Storage Pool Creation Issues

This section groups descriptions of errors during pool creation by those relating to devices, redundancy, or mount points.

Some error messages suggest using the –f option to override the reported errors. However, as a general rule, you should repair errors instead of overriding them.

Devices Actively Being Used

When you create ZFS pools on specific devices, ZFS first determines if those devices are in use either by ZFS itself or some other part of the operating system. If the devices are in use, then appropriate error messages are displayed.

You must manually correct the errors reported by the following messages before attempting to create the pool again.

Mounted file system

The disk contains a file system that is currently mounted. To correct this error, use the umount command.

File system in /etc/vfstab

The disk contains a file system that is listed in the /etc/vfstab file but the file system is not currently mounted. To correct this error, remove or comment out the line in the /etc/vfstab file.

Dedicated dump device

The disk is in use as the dedicated dump device for the system. To correct this error, use the dumpadm command.

Part of a ZFS pool

The disk or file is part of an active ZFS storage pool. To correct this error, use the zpool destroy command to destroy the other pool provided that the pool is no longer needed. If that pool is still needed, use the zpool detach command to detach the disk from that pool. You can detach a disk only from a mirrored storage pool.

The following in-use checks serve as helpful warnings. You can override these warnings by using the –f option to create the pool:

Contains a file system

The disk contains a known file system but it is not mounted or being used.

Part of volume

The disk is part of a Solaris Volume Manager volume.

Part of exported ZFS pool

The disk is part of a storage pool that has been exported or manually removed from a system. In the latter case, the pool is reported as potentially active because the disk might be a network-attached drive in use by another system. Be cautious when overriding a potentially active pool.

Mismatched Redundancy Levels

Creating pools with virtual devices of different redundancy levels results in error messages similar to the following example:

$ zpool create system1 mirror c1t0d0 c2t0d0 mirror c3t0d0 c4t0d0 c5t0d0
invalid vdev specification
use '-f' to override the following errors:
mismatched replication level: 2-way mirror and 3-way mirror vdevs are present

Similar error messages are generated if you create mirrored or RAID-Z pools using devices of different sizes.

Maintaining mismatched levels of redundancy results in unused disk space on the larger device, which is an inefficient use of ZFS. You should correct these errors instead of overriding them.

Default Mount Point for Storage Pools Not Empty

When a pool is created, the default mount point for the top-level file system is /pool-name. If this directory exists and contains data, an error occurs.

To create a pool with a different default mount point, use the zpool create –m mountpoint command. For example:

$ zpool create system1 c1t0d0
default mountpoint '/system1' exists and is not empty
use '-m' option to provide a different default
$ zpool create -m /export/zfs system1 c1t0d0

This command creates the new pool system1 and the system1 file system with a mount point of /export/zfs.

For more information about mount points, see Managing ZFS Mount Points.