To repair storage pools and logical volumes, NSS uses the VERIFY and REBUILD utilities.
VERIFY checks the file system integrity for an NSS pool by searching for inconsistent data blocks or other errors. This utility indicates if there are problems with the file system.
REBUILD verifies and uses the existing leaves of an object tree to rebuild all the other trees in the system. You need to deactivate pools (and all the volumes in the pools) before you run REBUILD so users cannot access the volumes you are rebuilding.When you deactivate a storage pool, all the volumes in the pool automatically deactivate.
REBUILD also copies errors and transactions into an error file called volume_name.rlf at the root of the DOS drive on your server. Every time you rebuild a particular NSS volume, the previous error file is overwritten. If you want to keep old error files, move them to another location. You can check the error file whenever an NSS volume does not come up in active mode after a rebuild.
REBUILD is not equivalent to VREPAIR. You should use REBUILD only as a last resort to recover the file system. If you use it to recover from data corruption, you will likely lose some data in the process.
When you use REBUILD and VERIFY a log file is generated to the root of the DOS drive.
To run rebuild, enter the following command at the server console:
nss/poolrebuild=<poolname>
This verifies and accounts for all blocks in the system. If the volume has errors, the errors appear on the screen. The NSS volume remains in maintenance mode; otherwise, it reverts to the active state. You then need to mount the volume again.
You can also verify a pool by entering nss /verify for a list of pool names, and then selecting the pool. Verify is a read-only assessment of the pool.