Solaris: Recovering From Soft Partition Problems

Recovering From Soft Partition Problems

The following sections show how to recover configuration information for soft partitions. You should only use these techniques if all of your state database replicas have been lost and you do not have a current or accurate copy of metastat -p output, the md.cf file, or 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 and do not appear to the user of the soft partition. If all Solaris Volume Manager configuration 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command should only be used when you have lost both your metadb and your md.cf files, and your md.tab is lost or out of date.

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Note - This procedure only works to recover soft partition information, and does not assist in recovering from other lost configurations or for recovering configuration information for other Solaris Volume Manager volumes.

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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.

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Configuration information about your soft partitions is stored on your devices and in your state database. Since either of these sources could be corrupt, you must tell 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. If the metarecover command reports an inconsistency, however, 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.

1. Read the Background Information About Soft Partitions.

2. Review the soft partition recovery information by using the metarecover command.

   metarecover component-p {-d }

   In this case, component is the c*t*d*s* name of the raw component. The -d option indicates to scan the physical slice for extent headers of soft partitions.

   For more information, see the metarecover(1M) man page.

p/s: soft partitions is the best way to extend the 7 slices in solaris volume manager, it has capability to slice it to how many space that we want but it will slow down the performance a little bit