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PRIMECLUSTERGlobal Disk Services Configuration and AdministrationGuide 4.5
FUJITSU Software

D.17 sdxshadowvolume - Shadow volume operations

SYNOPSIS

sdxshadowvolume -F -c class [-v volume,...] 
sdxshadowvolume -M -c class {-g group | -d disk} -v volume -s size
sdxshadowvolume -N -c class [-v volume,...] [-e  mode=val]
sdxshadowvolume -R -c class -v volume

DESCRIPTION

Use sdxshadowvolume to perform operations on shadow volumes specified by volume.
This command can be executed with superuser access privileges only.


PRIMARY OPTIONS

You have a choice of the following options.

-F

oFfline
Stops one or more shadow volumes specified by volume,... By default all shadow volumes within class are turned off. Volumes turned off cannot be accessed.

This results in an error if the volume is in use.


-M

Make
Creates a shadow volume specified by volume to the highest level shadow group specified by group or to a shadow disk of the single type specified by disk. size indicates the number of blocks on volume, class indicates the name of the shadow class associated with group or disk.

The access mode of the created shadow volume is ro (read-only). Synchronization copying is not performed on shadow volumes of the mirror type. The attribute of just resynchronization mode is off. In addition, the physical slice attribute is always off even though the slice configuring the shadow volume is registered with the disk label. A maximum of 1024 shadow volumes can be created to the same group or disk.

When creation is completed, the shadow volume is activated and can be accessed using the following special files:

    /dev/sfdsk/class/rdsk/volume
    /dev/sfdsk/class/dsk/volume

Create shadow volumes conforming to the following rules in order to use the shadow volumes to access data in the corresponding logical volumes.

  • Equal to the corresponding logical volumes in size. For volume sizes, check the BLOCKS field displayed with the sdxinfo -V command.

  • Whose first block numbers must be consistent with the first block numbers of the corresponding logical volumes. Therefore, create shadow volumes within the same shadow group or shadow disk in ascending order in conformity to the order of the first block numbers of the corresponding logical volumes. For the first block numbers of volumes, check the 1STBLK field displayed with the sdxinfo -V command.

The features of created shadow volumes when group is the mirror type and the stripe type are as below.

When group is a mirror type


In a shadow group of the mirror type, shadow volumes of the mirror type with mirror-multiplexing equal to the number of shadow disks or lower level shadow groups connected (maximum of eight) are created. When only one shadow disk or one lower level shadow group is connected, the created shadow volume will not be mirrored.

Synchronization copying is not performed on shadow volumes even if the shadow volumes of the mirror type are created. To ensure synchronization for a shadow volume of the mirror type, the mirror volume must be properly synchronized with GDS or SynfinityDisk that manages the mirror volume corresponding to the shadow volume.

When group is a stripe group


In a shadow group of the stripe type, shadow volumes of the stripe type with columns equal to the number of shadow disks or lower level shadow groups connected (maximum of 64) are created. When only one shadow disk or one lower level shadow group is connected, a shadow volume cannot be created.


-N

oNline
Activates one or more shadow volumes specified by volume,... By default all shadow volumes within class are activated. The activated shadow volumes become accessible.

Synchronization copying is not performed on shadow volumes if the shadow volumes of the mirror type are activated. To ensure synchronization for a shadow volume of the mirror type, the mirror volume must be properly synchronized with GDS or SynfinityDisk that manages the mirror volume corresponding to the shadow volume.


-R

Remove
Removes a shadow volume specified by volume and releases the disk area that the shadow group or the shadow disk of the single type was occupying.

This results in an error if the shadow volume is active.

No data stored on volume will be lost due to this removal of volume.


SUB OPTIONS

Sub options are as follows:

-c class

class indicates the name of the shadow class to which the shadow volume as the object of the operation belongs, or in which the shadow volume is to be created.


-d disk (when using -M)

disk indicates the name of a shadow disk of the single type in which the shadow volume of the single type will be created.


-e mode=val (when using -N)

Specifies the access mode for one or more shadow volumes that will be activated.

You can specify either of the following options to val.

rw

Sets the access mode to read and write.

ro

Sets the access mode to read only. Opening a read-only volume in the write mode will result in an error.

Although shadow volumes are activated in the access mode specified by val, the access mode attributes for the shadow volumes will remain unchanged. The access mode specified by val ("current access mode") is valid only while the shadow volume is active and will become invalid once the shadow volume is stopped. When the shadow volume is restarted, it will start in the mode according to the access mode attribute ("default access mode") unless the access mode is specified by this option.

In order to start a shadow volume that is already activated on the current node in a different access mode, you must first stop the shadow volume.


-g group (when using -M)

group indicates the name of a shadow group in which the shadow volume will be created.


-s size (when using -M)

Specifies the size of the volume being created in blocks (decimal numbers). One block is 512 bytes.

When group is the stripe type, the size of volume created will be the size rounded up to a common multiple of the stripe width multiplied by stripe columns and the cylinder size. In other cases, the size of volume created will be the size rounded up to the integer multiple of the cylinder size.


-v volume (when using -M,-R)

volume indicates the name of the shadow volume as the object of the operation.


-v volume,... (when using -F,-N)

volume,... indicates the names of one or more shadow volumes as the objects of the operation. To specify multiple shadow volumes, separate each volume name with a comma (,). volume which can be specified is up to 400.


RETURNED VALUE

Upon successful completion, a value of 0 is returned.
Otherwise, a non-zero value is returned.