Recovering From Soft Partition Problems
This section shows how to recover configuration information for soft partitions. You should
only use the following procedure if all of your state database replicas have
been lost and you do not have one of the following:
A current or accurate copy of metastat -p output
A current or accurate copy of the md.cf file
An up-to-date md.tab file
How to Recover Configuration Data for a Soft Partition
At the beginning of each soft partition extent, a sector is used to
mark the beginning of the soft partition extent. These hidden sectors are
called extent headers. These headers do not appear to the user of the soft
partition. If all Solaris Volume Manager configuration data is lost, the disk can
be scanned in an attempt to generate the configuration data.
This procedure is a last option to recover lost soft partition configuration information.
The metarecover command should only be used when you have lost both your
metadb and md.cf files, and your md.tab file is lost or out of
date.
Note - This procedure only works to recover soft partition information. This procedure does not
assist in recovering from other lost configurations or for recovering configuration information for
other Solaris Volume Manager volumes.
Note - If your configuration included other Solaris Volume Manager volumes that were built on
top of soft partitions, you should recover the soft partitions before attempting to
recover the other volumes.
Configuration information about your soft partitions is stored on your devices and in
your state database. Since either source could be corrupt, you must indicate to
the metarecover command which source is reliable.
First, use the metarecover command to determine whether the two sources agree. If
they do agree, the metarecover command cannot be used to make any changes.
However, if the metarecover command reports an inconsistency, you must examine its output
carefully to determine whether the disk or the state database is corrupt. Then,
you should use the metarecover command to rebuild the configuration based on
the appropriate source.
- Read the Configuration Guidelines for Soft Partitions.
- Review the soft partition recovery information by using the metarecover command.
# metarecover component-p -d
- component
Specifies the cntndnsnname of the raw component
- -p
Specifies to regenerate soft partitions
- -d
Specifies to scan the physical slice for extent headers of soft partitions
Example 25-2 Recovering Soft Partitions from On-Disk Extent Headers
# metarecover c1t1d0s1 -p -d
The following soft partitions were found and will be added to
your metadevice configuration.
Name Size No. of Extents
d10 10240 1
d11 10240 1
d12 10240 1
# metarecover c1t1d0s1 -p -d
The following soft partitions were found and will be added to
your metadevice configuration.
Name Size No. of Extents
d10 10240 1
d11 10240 1
d12 10240 1
WARNING: You are about to add one or more soft partition
metadevices to your metadevice configuration. If there
appears to be an error in the soft partition(s) displayed
above, do NOT proceed with this recovery operation.
Are you sure you want to do this (yes/no)?yes
c1t1d0s1: Soft Partitions recovered from device.
bash-2.05# metastat
d10: Soft Partition
Device: c1t1d0s1
State: Okay
Size: 10240 blocks
Device Start Block Dbase Reloc
c1t1d0s1 0 No Yes
Extent Start Block Block count
0 1 10240
d11: Soft Partition
Device: c1t1d0s1
State: Okay
Size: 10240 blocks
Device Start Block Dbase Reloc
c1t1d0s1 0 No Yes
Extent Start Block Block count
0 10242 10240
d12: Soft Partition
Device: c1t1d0s1
State: Okay
Size: 10240 blocks
Device Start Block Dbase Reloc
c1t1d0s1 0 No Yes
Extent Start Block Block count
0 20483 10240In this example, three soft partitions are recovered from disk, after the state
database replicas were accidentally deleted.
