resyncflash
The resyncflash command is a point-in-time copy of an existing FlashCopy pair that was established with the -record and -persist parameters.
The resyncflash command copies only the parts of the volume that changed since the last point-in-time copy.
Parameters
When a FlashCopy pair is established with the -record and -persist parameters, the pair initially synchronizes. A record of all host write operations to the source is maintained in the source volumes. When the resyncflash command is specified on the FlashCopy pair, the new data that is written to the source is copied to the target. The parameters that you specify in this command replace the parameters that you previously specified for the existing relationship. To keep the -record and -persist parameters, you must specify these parameters in the resyncflash command.
- -dev storage_image_ID
- (Optional)The storage image ID consists of the manufacturer name, machine type, and serial number. The storage image ID is required if you do not specify a fully qualified ID for the source and target volume or do not set the devid variable in your profile or through the setenv command. The storage image ID is also required if HMC is aware of more than one storage image. Using the -dev parameter temporarily overrides any defined value for devid for the current command.
- -tgtpprc
- (Optional) Allows the FlashCopy target volume to be a remote mirror and copy source volume.
- -tgtoffline
- (Optional) Rejects the resyncflash command if the target volume is online for host system access. This parameter applies only to count key data (CKD) volumes.
- -tgtinhibit
- (Optional) Prevents host system write operations to the target volume while the FlashCopy relationship exists.
- -freeze
- (Optional) Starts the queue full condition for the
source volume. During the queue full condition, the
source volume reports a status of long busy. All writes
to the source volume are queued by the host and are written after
the queue full condition is reset. The queue full condition
is reset by an extended long busy timeout condition.
The timeout condition affects all FlashCopy source volumes that are
contained within a respective logical subsystem and that are established
or modified with this parameter.Note: Use the chlss and the chlcu commands to modify the extended long busy timeout setting.
- -record
- (Optional) This parameter, without the
-multinc parameter, creates a type 1 incremental FlashCopy relationship. The
type 1 FlashCopy® records data changes on both the source
and target volumes of the FlashCopy pair.
A single volume can be the source volume to up to 12 FlashCopy relationships, and these relationships can be any combination of normal, persistent, or incremental relationships. However, only a single type 1 incremental relationship can exist.
Select this parameter when you create an initial FlashCopy relationship that you later want to use with the resyncflash or reverseflash command. If the -multinc parameter is not selected, you can also use the setflashrevertible command.
When you select the -record parameter, the –persist parameter is automatically selected.
- -persist
- (Optional) Creates a persistent FlashCopy relationship in which the relationship remains
after the copy completes and remains indefinitely until you enter a rmflash
command against the FlashCopy pair. If this parameter is
not specified, a normal FlashCopy relationship is
created and is automatically removed after the copy completes.
A single volume can be the source volume to up to 12 FlashCopy relationships, and these relationships can be any combination of normal, persistent, or incremental relationships. However, only a single type 1 incremental relationship can exist.
See the -record parameter for a description of a type 1 incremental FlashCopy relationship and the -multinc parameter for a description of a type 2 incremental relationship.
When you select either the -record or the -multinc parameter, the persist parameter is automatically selected.
- -multinc
- (Optional) Creates a type 2 incremental FlashCopy relationship. The type 2 FlashCopy
records data changes only on the target volume of the FlashCopy pair.
A single volume can be the source volume to up to 12 FlashCopy relationships, and these relationships can be any combination of normal, persistent, or incremental relationships. However, only a single type 1 incremental relationship can exist.
The type 2 FlashCopy allows for more than one incremental FlashCopy relationship from the same source volume. However, because the change recording is maintained only on the target volume, the type 2 FlashCopy can cause a performance impact as more type 2 FlashCopy relationships are added.
Select this parameter when you create multiple FlashCopy volume pairs with the same source volume that you want to use with the resyncflash and reverseflash commands. However, FlashCopy pairs that are established with this modified recording method cannot be used with the setflashrevertible command.
When you select the -multinc parameter, the -persist and -record parameters are automatically selected.Note: Incrementing multiple relationships with the same source volume on a single command line (as shown below) is not currently supported:resyncflash -multinc 0000-00ff:0200-02ff 0000-00ff:0400-04ff 0000-00ff:0600-06ffInstead, you must issue the resyncflash commands separately. For example:resyncflash -multinc 0000-00ff:0200-02ff resyncflash -multinc 0000-00ff:0400-04ff resyncflash -multinc 0000-00ff:0600-06ff - -tgtse
- (Optional) The target volume that you are designating for a FlashCopy relationship might be a space-efficient logical volume. An error message is generated if the target volume that you are using to create the FlashCopy relationship is a space-efficient volume and you do not specify this parameter.
- -nocp
- (Optional) Inhibits a background copy. Data is copied from the source volume to the target volume only if a track on the source volume is modified. The FlashCopy volume pair relationship remains indefinitely until it is broken by a rmflash command or until all tracks on the source volume are modified.
- -cp
- (Optional) Starts a background copy. When the -tgtse parameter
is not specified and the -cp or the -nocp parameters
are specified, the background copy behavior is the default.Note: You cannot use the -nocp parameter with the -cp parameter in the same command.
- -seqnum flash_sequence_num
- (Optional) Associates the FlashCopy relationships that are established with the specified sequence number. You can use this sequence number as an identifier for a relationship or group of relationships. An example sequence number is 00010.
- -pmir no | required | preferred
- The Remote Pair Copy option that you want to use. The Remote Pair Copy option, sometimes called
Preserve Mirror, preserves synchronous Metro Mirror pairs when the
FlashCopy source and target volumes are both Metro Mirror primary volumes
and both Metro Mirror
secondary volumes on the same storage system. The FlashCopy operation is completed on both the local
site and the remote site.
- no
- FlashCopy operations are not completed on the remote site. If the target volume is a Metro Mirror primary volume, the remote copy might temporarily change to the duplex pending state. no is the default if the -pmir parameter is not specified.
- required
- FlashCopy operations do not change the state of the Metro Mirror primary volume pair to duplex pending. Both the source Metro Mirror volume pair and the target Metro Mirror volume pair must be in the full duplex state.
- preferred
- Uses the Remote Pair Copy option for FlashCopy operations when possible. The Remote Pair Copy
option cannot be used if the configuration is not correct or the state of the volume is not
supported by this function. Notes:
- The -preferred parameter is only valid for DS8870 and earlier system types.
- The -preferred parameter is not valid for targets which are also PPRC multi-target primaries.
- -resetreserve
- (Optional) Forcibly clears any SCSI reservation on the target volume and allows establishing of
a FlashCopy relationship. The reservation is not restored after the relationship is established.
- When this option is not specified and the target volume is reserved, the command fails.
- This option is ignored if the target is a CKD volume; this option is applicable only for fixed block volumes.
- source_volume_ID:target_volume_ID ... | -
- (Required) Increments a FlashCopy relationship for the source and target volume pairs with the specified IDs. This parameter accepts fully qualified volume IDs, which include storage image IDs, or a shortened version without storage image IDs if the -dev parameter is specified or you specify a value for the devid variable in your profile file. You must separate multiple FlashCopy pair IDs with spaces.
Example: Copying parts of a volume pair that changed since the last point-in-time copy
dscli> resyncflash –dev IBM.2107-75FA120 -freeze 0100:0200
Remote FlashCopy volume pair 0100:0200 successfully resynchronized.