Importing a Pool in Read-Only Mode

If a pool is so damaged that it cannot be accessed, importing in read-only mode might enable you to recover the pool's data. For example:

$ zpool import -o readonly=on system1
$ zpool scrub system1
cannot scrub system1: pool is read-only

When a pool is imported in read-only mode, the following conditions apply:

• All file systems and volumes are mounted in read-only mode.

• Pool transaction processing is disabled. Any pending synchronous writes in the intent log are not made until the pool is imported in read-write mode.

• Setting a pool property during the read-only import is ignored.

You can set the pool back to read-write mode by exporting and importing the pool. For example:

$ zpool export system1
$ zpool import system1
$ zpool scrub system1