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Procedure documentation Creating a New Link for a Lost Mirrored Chunk  Locate the document in its SAP Library structure

Use

This procedure is the second step in the recovery of a lost mirrored chunk with an Informix database. If the mirrored chunk has been accidentally deleted, you can recover it easily. By giving a chunk a new link, you can recover it quickly, before repairing or replacing the damaged disk.

Before you can recover a damaged or lost chunk, you have to proceed as follows:

  1. Replace the damaged disk with a new one (not described here).
  2. Link the chunk to another file or raw device (described in detail in this section).

Prerequisites

You have completed Identifying a Lost Mirrored Chunk.

Procedure

  1. Identify the chunk’s old link

    2. Enter a command like the following to see the link:

    $ cd informix/C11/sapdata/physdev3
    $ ls -l

    The link is then displayed:

    lrwxr-xr-x 1 root sys....2 17:40 data3->/dev/rdsk/3s0

    In this example, the chunk was linked to raw device /dev/rdsk/3s0 .

  2. Delete the chunk’s old link using rm

    3. Enter a command like the following:

    $ rm data3
  3. Specify a new link

Now you can specify a new link to a raw device on another disk for the mirrored chunk. Enter a command like the following:

$ ln -s /dev/rdsk/4s0 data3

Use this procedure with care. Note that a raw device usually has several chunks. In this case, it is not sufficient to link only the one chunk.

Result

Now that you have created a new link for the lost mirrored chunk, you can go on to Recovering a Lost Mirrored Chunk Online.

 

See also:

Informix documentation