PRIMECLUSTER Global Disk Services Configuration and Administration Guide 4.1 (Solaris(TM) Operating System)

D.15 sdxshadowdisk - Shadow disk operations

SYNOPSIS

sdxshadowdisk -C -c class -g group -d disk,...
[-a attribute=value[,attribute=value]]

sdxshadowdisk -D -c class -g group -d disk

sdxshadowdisk -M -c class
-d device=disk[:type][,device=disk[:type],...]

sdxshadowdisk -R -c class -d disk

 

DESCRIPTION

Use sdxshadowdisk to perform operations on shadow disks specified by disk.
This command can be executed with superuser access privileges only.

 

PRIMARY OPTIONS

You have a choice of the following options.

-C

Connect

Connects one or more shadow disks (single type or undefined type) specified by disk,... to a group specified by group. class indicates the name of the shadow class with which disk is registered.

If there is no shadow group with the name specified by group, it is created automatically.

You cannot connect a shadow disk of the single type to an existing shadow group. Also, multiple shadow disks of the single type cannot be connected to the same shadow group simultaneously.

The type attribute of a shadow disk connected to a shadow group will be changed to match the type attribute of that group (mirror, stripe or concatenation). Shadow disks and lower level groups that are connected to the same shadow group will be mirrored, striped or concatenated, depending on their type attributes.

Details about connecting shadow disks to mirror type, stripe type, and concatenation type shadow groups are described below.

- When connecting to a shadow group of the mirror type

Shadow disks and lower level shadow groups connected to the same shadow group of the mirror type will be mirrored one another. When only one shadow disk or one lower level shadow group is connected to a shadow group of the mirror type, the shadow volume created within that shadow group will not be mirrored. When configuring a mirroring environment with "n"-way multiplexing, "n" numbers of shadow disks or lower level shadow groups must be connected. A maximum of eight-way multiplex mirroring is supported.

If a shadow disk is connected to a shadow group of the mirror type including a shadow volume, synchronization copying of the shadow volume is not performed. 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 volumes corresponding to shadow volumes.

By connecting a shadow disk of the single type including a shadow volume to a group of the mirror type, the shadow volume can also be changed from the single type to the mirror type.

The available size of a shadow group of the mirror type (available capacity as shadow volumes) will be the same size as that of the smallest shadow disk or lower level shadow group connected. If connecting disk results in a decrease in the available size of group, a warning message will be sent to standard error output.

- When connecting to a shadow group of the stripe type

Shadow disks specified by disk,... will be connected to group in the order they are listed. Disks connected to a stripe group in another domain should be connected in the same order. Alternatively, destination disks copied with the copy functions of disk units from disks connected to a stripe group should be connected in the same order. For the disk connecting order, check the DISKS field displayed with the sdxinfo -G command. Respective shadow disks and lower level shadow groups connected to the same shadow group of the stripe type will configure stripe columns, and will be striped in the order they were connected. When only one shadow disk or one lower level shadow group is connected to a shadow group of the stripe type, a shadow volume cannot be created within that shadow group. When striping "n" number of columns, "n" number of shadow disks or lower level shadow groups must be connected. Stiping of two or more columns up to 64 columns is supported.

When a shadow group of the stripe type specified by group already exists, stripe columns will be added after the existing stripe columns in group, in the order they are specified by disk,.... However, a shadow disk with the available size smaller than the stripe width cannot be connected to the existing shadow group of the stripe type. In addition, you cannot increase stripe columns by connecting shadow disks to a stripe group with a shadow volume, or to a stripe group connected to a higher level shadow group.

The available size of a shadow group of the stripe type (available capacity as shadow volumes) equals the available size of the smallest shadow disk (or lower level shadow group) multiplied by the number of stripe columns, and rounded down to the common multiple of the stripe width times stripe columns and the cylinder size. If connecting disk decreases the available size of group, a warning message will be sent to standard error output.

You cannot connect a shadow disk of the single type to a shadow group of the stripe type.

- When connecting to a shadow group of the concatenation type

Shadow disks connected to the same shadow group of the concatenation type will be concatenated in the order they are specified by disk,... Disks connected to a concatenation group in another domain should be connected in the same order. Alternatively, destination disks copied with the copy functions of disk units from disks connected to a concatenation group should be connected in the same order. For the disk connecting order, check the DISKS field displayed with the sdxinfo -G command. A maximum of 64 disks can be concatenated.

The available size of a shadow group of the concatenation type (available capacity as shadow volumes) equals the total of the available size of connected shadow disks.

The available size of an existing shadow group of the concatenation type can be increased by connecting shadow disks. When a shadow group of the concatenation type specified by group already exists, shadow disks will be concatenated in the order they were specified by disk,... after the disk that was last concatenated in group. However, you cannot add a shadow disk to a lower level shadow group of the concatenation type if the highest level shadow group of the stripe type already has a shadow volume. Also if the order of connecting shadow groups from the higher level is the mirror type, the stripe type and the concatenation type, a shadow disk cannot be connected to the lowest level shadow group of the concatenation type. You cannot connect a shadow disk of the single type to a shadow group of the concatenation type.

 

-D

Disconnect

Disconnects a shadow disk specified by disk from a shadow group specified by group. class indicates the name of the shadow class with which the disk is registered, and group indicates the name of the shadow group to which disk is connected.

The disconnected shadow disk will have the original type attribute again (single or undefined).

If only disk is connected to group, group will automatically be removed upon disconnecting disk. However, when disk is the only object connected to group and group is connected to a higher level shadow group, disconnection will result in an error. In such a case, disconnect group from the higher level shadow group using the sdxshadowgroup -D command, and then disconnect disk.

You cannot disconnect disk if the disconnection will result in a change on the status of any of the existing shadow volumes within group.

Conditions that do not allow you to disconnect a shadow disk from a shadow group of the mirror type, stripe type or concatenation type are as below.

- When disconnecting from a shadow group of the mirror type

For example, you cannot disconnect disk from a shadow group of the mirror type specified by group if a shadow volume exists within the group, and disk is the only object connected to group.

- When disconnecting from a shadow group of the stripe type

You cannot disconnect a shadow disk from a shadow group of the stripe type including an existing shadow volume, or from a shadow group of the stripe type connected to a higher level shadow group..

- When disconnecting from a shadow group of the concatenation type

The only disk you can disconnect from a shadow group of the concatenation type is the shadow disk that was concatenated last.

A shadow disk containing shadow volume data cannot be disconnected from a shadow group of the concatenation type.

You cannot disconnect a shadow disk from a lower level shadow group of the concatenation type if the highest level shadow group has an existing shadow volume. Also, if the order of connecting shadow groups from the higher level is the mirror type, stripe type and the concatenation type, a shadow disk cannot be disconnected from the lowest level shadow group of the concatenation type.

 

-M

Make

Registers one or more physical disks specified by device with a shadow class. class indicates the name of the destination shadow class. Once physical disks are registered, they can then be managed by GDS. Accordingly, the user can perform operations on the disk by use of the disk name specified by disk. However, device will be no longer managed by GDS if the current node is rebooted or if the GDS daemon on the current node is re-launched because the configuration information of a shadow class is only retained on the memory of the current node but not stored on the private slice.

If no shadow class with the same name as class exists, then it is automatically created. The type attribute of the shadow class is "local," and objects in the shadow class are only available on the current node.

A shadow class can include physical disks that are not registered with other classes in the current domain and on which the private slices of GDS or SynfinityDisk exist. In other words, a shadow class can include physical disks that are registered with classes in other domains and physical disks to which the private slices of SDX disks are copied with the copy functions of disk units. Physical disks can be registered with the same shadow class if they are registered with classes that have the same names in other domains or if they are destinations to which the private slices of SDX disks registered with classes with the same names are copied with the copy functions of disk units. In addition, disks with the private slices of different sizes cannot be registered with the same shadow class.

While contents on physical disks (excluding keep disks) registered by the sdxdisk command are initialized, contents on physical disks registered by the sdxshadowdisk command are not changed.

 

-R

Remove

Removes a shadow disk specified by disk from a shadow class specified by class. class indicates the name of the shadow class with which disk is registered.

The removed shadow disk is no longer managed by GDS.

When the last shadow disk is removed from class, the shadow class definition is automatically removed as well.

A shadow disk cannot be removed when a shadow volume exists within disk, or when disk is connected to a shadow group.

 

SUB OPTIONS

Sub options are as follows:

-a attribute=value[,attribute=value] (when using -C)

When using the -C option and defining a new group name with the -g option, a new shadow group is automatically created. This option sets attribute to value for the created group attribute.
The attribute indicates the attribute name, and the value indicates the attribute value. The equal sign (=) is always necessary between attribute and value. When specifying multiple attributes, each specifier set must be separated by a comma (,).

If no shadow group is created, specifying value different from the existing group attribute value will result in an error. You cannot change the attribute value of an existing group.

You can specify one of the following combination to attribute and value.

If multiple attributes are specified and any error occurs, the entire process is canceled.

type=mirror, type=stripe or type=concat (default is mirror)

Sets the type attribute of group.

mirror

Sets type attribute to "mirror".

stripe

Sets type attribute to "stripe".

concat

Sets type attribute to "concatenation".

width=blks (default is 32)

Sets the stripe width of group. blks indicates the stripe width in blocks (decimal numbers). One block is 512 bytes. For blks, you can specify an integer that is the power of two, is equal to or larger than one and is equal to or smaller than the available size of the smallest shadow disk among disks specified by disk,... If group is not the stripe type, this option will cause in an error.

 

-c class

class indicates the name of the shadow class to which the target shadow disk is registered or is to be registered.

 

-d device=disk[:type] [,device=disk[:type],...] (when using -M)

device indicates the name of the physical disk, disk, the name of the disk, and type, the type attribute of the shadow disk. An equal sign (=) always follows device, and if type is specified it must be separated from disk by a colon (:). To register multiple devices, separate each specifier set as above with a comma (,).

The physical disk name can be specified in either the following formats:

cCtTdD          (for normal hard disks)
mphdI           (for MPHD disks)
mplbI       (for MPLB disks)
emcpowerN (for emcpower disks)

Where C is the controller number, T is the target ID, D is the disk number, I is the MPHD instance number or the MPLB instance number, and N is the emcpower device number.
The emcpower device number is a single digit number or double or more digit numbers by numbers from 0 to 9, and cannot contain a lower case letter corresponding to the slice number.

If device is registered with a class in another domain, the same disk name as that in the domain must be specified to disk. If device is a destination to which the private slice of an SDX disk is copied with a disk unit's copy function, the same disk name as the SDX disk name must be specified to disk.

One of the following types can be specified to type. The default value for the registered shadow disk is the undefined type.

single

Single type.

undef

Undefined type.

If "single" is specified to type, device is registered as a shadow disk of the single type. For the shadow disk of the single type, a shadow volume of the single type can be created with the sdxshadowvolume command even if it is not connected to a shadow group.

 

-d disk (when using -D, -R)

disk indicates the name of the shadow disk that is the object of the operation..

 

-d disk,... (when using -C)

disk indicates the name of the shadow disk that is the object of the operation. To connect multiple shadow disks, separate each disk name with a comma (,).

 

-g group (when using -C,-D)

group indicates the name of the shadow group to which the shadow disk as the object of the operation is connected or is to be connected.

 

RETURNED VALUE

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