Considerations, Examples – HP NonStop G-Series User Manual

Page 136

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Nomadic Disk Manager Interface

ServerNet Nomadic Disk (Release 2) User’s Guide 523968-001

7- 16

TAKE Command

UPPATH { -P | -B | -M | -MB | PRIMARY | MIRROR }

specifies that an UP PATHS command be issued instead of the UP VOLUMES
command. Refer to

UP Command

on page 7-17.

Immediately after ownership is taken, all the Nomadic volumes are in a DOWN
state. The TAKE command normally automatically issues the UP VOLUMES
command.

UPPATH is used only in special circumstances or emergencies.

Considerations

If a TAKE command does not contain the SEGMENT option, nor the DATA option,
it works on the current segment. If a current segment has not been set with the
ASSUME command, the last segment defined in the configuration file becomes the
assumed segment. If that segment is a DATA segment, issuing a TAKE command
has the same effect as issuing a TAKE DATA command. If that segment is a
SPARE segment, the TAKE command works only on that segment. Even though
SPARE segments are not directly supported, the code still allows them. Therefore,
you should always issue a TAKE DATA command rather than a simple TAKE
command.

In a ServerNet Nomadic Disk environment, all data segments must be owned by
the same node. Therefore, whenever a data segment is given away, all data
segments are given away, unless explicit instructions indicate otherwise.

In a planned switchover, you should issue the GIVE command on the owning node
before issuing a TAKE command on the destination node. However, a GIVE
command is not strictly necessary and might not always be possible in an
emergency if, for example, the giving node is down. A TAKE command is always
necessary, even if the GIVE command finishes properly.

The results of each intermediate step of a TAKE operation are written to the
Nomadic Disk Manager’s outfile. The steps for the TAKE DATA command are:

1. Switch paths to OWNED.

2. UP VOLUMES or UP PATHS, if the UPPATH parameter is used.

Examples

TAKE SEGMENT ONE, ONLY

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