Checking SnapMirror data transfer status

Why to check data transfer status

You check data transfer status, using the snapmirror status command, to determine the status of all existing SnapMirror relationships on the storage system.

What checking status shows you

If you check the status and you enabled SnapMirror, messages of the following form are displayed:

systemA> snapmirror status

Snapmirror is on.

Source                   Destination             State          Lag       Status

systemA:vol0              systemA:vol1             Snapmirrored   02:25:11  Transferri
ng (60 MB done)

systemB:/vol/vol1/qtree   systemB:/vol/vol3/qtree  Quiesced       00:01:15  Idle

You see a status report for any SnapMirror source that contains the base Snapshot copy, and for any destination in a current SnapMirror relationship or listed in the /etc/snapmirror.conf file. Destinations that were broken through the snapmirror break command but still contain the base Snapshot copy are listed.

If you check the status of data transfer and you did not enable SnapMirror, the following message is displayed:

systemA> snapmirror status

Snapmirror is off.

The status of SnapMirror relationships, if any, are still displayed, as shown in the example above.

Checking the status

To check the status of data copying and check on how current the information at a destination is, complete the following step.

Step	Action
1	Enter the following command: *snapmirror status [options] [[system:] [path] ...]* options can be one of the following: `-l` displays the long format of the output, which contains more detailed information.See Example 2, below. `-q` displays which volumes or qtrees are quiesced or quiescing. For more information, see Example 3, below, and Stabilizing (quiescing) destinations before a Snapshot copy. system is the name of the source storage system. path is the name of the source volume or the path to and name of the source qtree. Result If no arguments or options are given, SnapMirror displays a message showing whether a transfer is in progress, how much of the data transfer has been completed, the state of the destination, and the amount of time since the last Snapshot copy was created and transferred successfully, as shown in Example 1.

Step

Action

Enter the following command:

snapmirror status [options] [[system:] [path] ...]

options can be one of the following:

-l displays the long format of the output, which contains more detailed information.See Example 2, below.
-q displays which volumes or qtrees are quiesced or quiescing. For more information, see Example 3, below, and Stabilizing (quiescing) destinations before a Snapshot copy.

system is the name of the source storage system.

path is the name of the source volume or the path to and name of the source qtree.

Result

If no arguments or options are given, SnapMirror displays a message showing whether a transfer is in progress, how much of the data transfer has been completed, the state of the destination, and the amount of time since the last Snapshot copy was created and transferred successfully, as shown in Example 1.

Example 1:

With no options, the information displayed by the snapmirror status command might look like the following. See the table What the categories in the command output mean for more information.

systemB> snapmirror status

Snapmirror is on.

Source                 Destination            State          Lag        Status

systemA:vol0            systemB:vol2            Broken-off     29:09:58   Idle

systemC:vol0            systemB:vol3            Snapmirrored   00:09:53   Idle with 
restart checkpoint (23 MB done)

systemC:vol4            systemB:vol5            Snapmirrored   00:04:58   Transferring

(36 MB done)

systemA:/vol/vol1/qt5   systemB:/vol/vol4/qt5   Quiesced       00:05:12   Idle

systemC:/vol/vol2/qt1   systemB:/vol/vol1/qt2   Snapmirrored   00:02:33   Quiescing

Example 2:

With the -l option, the configuration described in Example 1 would look like this:

systemB> snapmirror status -l

Snapmirror is on.

Source:                 systemA:vol0

Destination:            systemB:vol2

Status:                 Syncing

Progress:                60 KB

State:                  Source

Lag:                    00:01:17

Mirror Timestamp:       Sat Jul 15 00:50:02 GMT 2000

Base Snapshot           tpubs-f720(0016791363)_vol2.1249

Current Transfer Type:  -

Current Transfer Error: -

Contents:               -

Last Transfer Type:     Update

Last Transfer Size:     1052 KB

Last Transfer Duration: 00:00:02

Last Transfer From:     systemA:vol0

Source:                 systemC:vol0

Destination:            systemB:vol3

Status:                 Idle with restart checkpoint

Progress                23552 KB done

State:                  Snapmirrored

Lag:                    00:09:53

Mirror Timestamp:       Sun Jul 16 05:50:07 GMT 2000

Base Snapshot:          system2(0016778780)_vol3.985

Current Transfer Type:  -

Current Transfer Error: Abort by user

Contents:               Replica

Last Transfer Type:     Update

Last Transfer Size:     432000 KB

Last Transfer Duration: 00:01:23

Last Transfer From:     systemC:vol0

Source:                 systemC:vol4

Destination:            systemB:vol5

Status:                 Transferring

Progress                36864 KB done

State:                  Snapmirrored

Lag:                    00:04:58

Mirror Timestamp:       Sun Jul 16 05:55:02 GMT 2000

Base Snapshot:          systemB(0016778780)_vol5.57843

Current Transfer Type:  Scheduled

Current Transfer Error: -

Contents:               Replica

Last Transfer Type:     Scheduled

Last Transfer Size:     345000 KB

Last Transfer Duration: 00:03:23

Last Transfer From:     systemB:vol4

Source:                 systemC:/vol/vol1/qt5

Destination:            systemB:/vol/vol4/qt5

Status:                 Idle

Progress                -

State:                  Quiesced

Lag:                    0:05:12

Mirror Timestamp:       Sun Jul 16 05:56:12 GMT 2000

Base Snapshot:          systemB(0016778780)_vol_vol4_qt5.54

Current Transfer Type:  -

Current Transfer Error: -

Contents:               Replica

Last Transfer Type:     Scheduled

Last Transfer Size:     45000 KB

Last Transfer Duration: 0:00:12

Last Transfer From:     systemC:/vol/vol1/qt5

Source:                 systemC:/vol/vol2/qt1

Destination:            systemB:/vol/vol4/qt2

Status:                 Quiescing

Progress                -

State:                  Snapmirrored

Lag:                    0:02:33

Mirror Timestamp:       Sun Jul 16 05:58:20 GMT 2000

Base Snapshot:          systemB(0016778780)_vol_vol4_qt2.122

Current Transfer Type:  -

Current Transfer Error: -

Contents:               Transitioning

Last Transfer Type:     Scheduled

Last Transfer Size:     80 KB

Last Transfer Duration: 0:00:08

Last Transfer From:     systemC:/vol/vol2/qt1

Example 3:

With the -q option, the output might look like this:

systemC> snapmirror status -q

Snapmirror is on.

vol3 is quiesced

vol2 has quiesced/quiescing qtrees:

         /vol/vol2/qt1 is Quiescing

         /vol/vol2/qt2 is Quiesced

What the categories in the command output mean

Information messages that the snapmiror status command can display are as follows.

SnapMirror status entries on the source category are as follows.

Source entry	Description
system:vol	The source system and source volume
system:qtree_path	The source system and qtree path
-	Either the SnapMirror destination is an imported volume without an entry in the /etc/snapmirror.conf file, or a Data ONTAP upgrade is in progress.
system:tape_device	The source tape device; transfer from this tape device is still in progress
base snapshot	The name of the base Snapshot copy from which a completed transfer was made, if the source is a tape device and there is no entry in the /etc/snapmirror.conf file for the destination

SnapMirror status entries on the destination category are as follows.

Destination entry	Description
system:vol	The destination system and volume
system:qtree_path	The destination system and qtree path
system:tape_device	The destination tape device; transfer to this tape device is in progress
tape_destination	Displayed after a transfer to tape is finished. The `snapmirror destinations` command also displays this information. For more information, see Listing SnapMirror destinations for a volume in a cascading series.

State entry	Description
Uninitialized	The destination is listed in the /etc/snapmirror.conf file, but the volume or qtree has not been initialized or the destination is being initialized.
Snapmirrored	The volume or qtree is in a SnapMirror relationship.
Broken-off	The destination was in a SnapMirror relationship, but a `snapmirror break` command made the volume or qtree writable. This state is reported as long as the base Snapshot copy is still present in the volume. If the Snapshot copy is deleted, the state is listed as "uninitialized" if the destination is in the /etc/snapmirror.conf file or is no longer listed if it is not. A successful `snapmirror resync` command restores the snapmirrored status.
Quiesced	SnapMirror is in a consistent internal state and no SnapMirror activity is occurring. In this state, you can create Snapshot copies with confidence that all destinations are consistent. The `snapmirror quiesce` command brings the destination into this state. The `snapmirror resume` command restarts all SnapMirror activities.
Unknown	The destination volume or the volume that contains the destination qtree is in an unknown state. It might be offline or restricted.
Source	When the `snapmirror status` command is run on the source system and the destination is on another system, the state of the destination is unknown, so the source status is reported.

Lag entry	Description
hh:mm:ss	Indicates the difference between the current time and the timestamp of the Snapshot copy last successfully transferred to the destination.
-	The destination is not initialized.

SnapMirror status entries on the status category are as follows.

Status entry	Description
Idle	No data is being transferred.
Idle with restart checkpoint (n XB done)	No data is being transferred. The last transfer attempt was aborted, but the transfer saved a restart checkpoint and thus can be restarted at the next attempt. Transfer sizes are reported in KB up to 10,240, MB up to 10,240, GB up to 10,240, then TB.
Transferring	Transfer has been initiated but has not yet started, or is just finishing.
Transferring (n XB done)	Data transfer is in progress. Transfer sizes are reported in KB up to 10,240, then MB up to 10,240, then GB up to 10,240, then TB.
Pending	The destination was not updated because of a transfer failure; the transfer will be retried automatically.
Pending with restart checkpoint (n XB done)	The destination was not updated because of a transfer failure. The transfer will be retried automatically from the restart checkpoint. Transfer sizes are reported in KB up to 10,240, MB up to 10,240, GB up to 10,240, then TB.
Aborting	A transfer is being aborted and cleaned up.
Quiescing	The specified volume or qtree is waiting for all existing transfers to complete. The destination is being brought into a stable state.
Resyncing	The specified volume or qtree is being matched with data in the common Snapshot copy.
Waiting	SnapMirror is waiting for a new tape to be put in the tape device.

Additional snapmirror status entries are as follows.

Additional -l option entries	Description
Progress	Shows the amount of data (in KB) transferred by the current transfer. Shows the restart check point if the status is Idle or Pending.
Mirror Timestamp	The timestamp of the last Snapshot copy successfully transferred from the source to the destination. Note A resynchronization may change the base Snapshot copy to a Snapshot copy with an older timestamp.
Base Snapshot copy	The name of the base Snapshot copy for the destination. For volumes in a SnapMirror relationship, this field is the same on the source side and the destination side. For qtrees in a SnapMirror relationship, the destination side lists the name of the exported Snapshot copy for that qtree on the destination. Note A resynchronization might change the name of the base Snapshot copy.
Current Transfer Type	Indicates the kind of transfer now in progress: scheduled, retry, resync, update, initialize, store, or retrieve. This field applies only to the destination side.
Current Transfer Error	Displays an error message if the latest transfer attempt failed.
Contents	Indicates whether the contents of the destination volume or qtree in the active file system are up-to-date replicas or in transition. The field applies only to the destination side. Under SnapMirror volume replication, the contents are always a replica. Under SnapMirror qtree replication, the contents are usually a replica, but sometimes are transitioning.
Last Transfer Type	Indicates the kind of transfer previously performed: scheduled, retry, resync, update, initialize, store, or retrieve. This field applies only to the destination side.
Last Transfer Size	Shows the amount of data (in KB) transferred in the last successful transfer.
Last Transfer Duration	Shows the elapsed time for the last successful transfer to complete. If the transfer failed and restarted, this includes time waiting to restart the transfer. If a transfer aborted and was retried from the beginning, it includes only the time required for the final successful attempt.
Last Transfer From	This field applies only to the destination side and shows the name of the source system and volume or qtree. This field is useful if you have changed the source in the /etc/snapmirror.conf file but the data is actually from the old source. For `snapmirror retrieve` (from tape) operations, this field lists the tape device used in the retrieve operation.