When the replication
direction is reversed, the source virtual disk and the destination virtual
disk will swap roles. So, the same virtual disks could be source or destination
depending on the direction that data is being transmitted.Virtual disk replications have a replication (operation) status and a transfer (data) status.
In this topic:
The replication status is the status of the replication operation.
Replication status is displayed in:
o The Virtual Disk Details page>Replication tab (Replication Status field). Replication and transfer status is also displayed under the icon when the replication is not healthy.
o The Virtual Disks List (Abbreviated status displayed in the Status column; complete status is displayed in the Replication Status column in Advanced View.)
When the replication
direction is reversed, the source virtual disk and the destination virtual
disk will swap roles. So, the same virtual disks could be source or destination
depending on the direction that data is being transmitted.
Status |
State Owner |
Description |
Active |
Source (Active side) |
The source virtual disk is in normal working condition and paths between the host and the virtual disk are online. The data stream is being actively monitored. Every write operation is collected, journaled and stored in a dedicated buffer. The data changes are subsequently transferred to the destination virtual disk. |
Active - xx % checked for consistency |
Source (Active side) |
The source virtual disk is active and before initialization occurs, the replication is being checked for consistency. Data on the source is compared to data on the destination to determine which blocks need to be transferred during initialization. Progress of the consistency check is displayed (xx% is the percentage completed.) |
Active - xx % initialized |
Source (Active side) |
The source virtual disk is active and initialization is in progress (xx% is the percentage completed). The source is transmitting data to the destination virtual disk. When the process is complete and all data has been written to the destination, the source and destination virtual disks will be identical copies. |
Activating |
Destination (Standby side) |
A transition state when a destination virtual disk is activated, but before the state becomes Active. |
Changing buffer folders |
Source (Active side) |
Folder for the replication buffer is in the process of changing after a new location was assigned. |
Deactivating |
Source (Active side) |
The status is valid only for the source while in the process of reversing replication directions. The status means that the source has stopped transmitting data changes to the destination and waits for the destination, which is in STANDBY, to send back a notification that all the data from replication buffer has been received and it is safe to switch replication direction. When the destination transmits the end-of-stream marker: o The destination becomes the source and immediately goes into ACTIVE and paths between the host and the virtual disk are on-lined. o The former source becomes the destination and goes into STANDBY and paths between the host and the virtual disk are offlined. |
In Log |
Source (Active side) |
The replication buffer folder is inaccessible and data changes are being logged in memory. Once the buffer is accessible again, saved data changes will be written to the buffer. Check the buffer folder to determine the reason that it is inaccessible (directory may be inaccessible or buffer may be full).
|
Split |
Source or Destination |
A status that is only valid for very short period of time. It denotes the moment of time just before the replication is split on source and destination. |
Splitting |
Source or Destination |
The status is valid only while in the process of splitting the replication, which begins when the command is invoked and continues until the end-of-stream marker is received at the destination. At that time, the source will be notified that it is safe to terminate the replication and the state will go to Split. |
Standby |
Destination (Standby side) |
Incoming data changes are being monitored on the destination server and de-staged to the destination virtual disk. Paths to the storage host are offline. |
Standby - xx% initialized |
Destination (Standby side) |
The source virtual disk is active and in full initialization (xx% is the percentage completed). The source (active) virtual disk is transmitting data to the destination (standby) virtual disk. When the process is complete and all data has been written to the destination, the source and destination virtual disks will be identical copies. |
Standby - xx% checked for consistency |
Destination (Standby side) |
The source virtual disk is active and a data consistency check is being performed on the destination after online initialization has been performed. Data on the destination is compared to data on the source to determine which blocks need to be transferred. Progress of the consistency check is displayed (xx% is the percentage completed.) If the consistency check is not proceeding an additional note may be appended, such as Buffer folder not set. |
Time lag |
Source (Active side) |
When there is more than one file waiting to be transferred, the time lag is also displayed in hours, minutes, and seconds, such as Active (00:05:25 time lag). The time lag (or latency) is an estimation of the amount of time required for the destination to receive the current buffered data transmissions. |
Undefined |
Source or Destination |
There is no connection with the destination and the state is unknown. |
Failures |
||
Both active |
Source or Destination |
Caused by a communications failure. The replication must be split and the replication relationship recreated and re-initialized to ensure data integrity. |
Both standby |
Source or Destination |
Caused by a communications failure. The correct virtual disk must be activated. |
Buffer folder not accessible |
Source (Active side) |
There is a problem with the buffer and it cannot be used. Check the buffer. |
Buffer folder not set |
Source or Destination |
Set the folder. |
Off-line |
Destination (Standby side) |
May occur if transfer service fails or is disabled, destaging to the standby virtual disk fails, data corruption occurs. Contact DataCore Technical Support for assistance. |
No replication defined on partner |
Source or Destination |
Occurs in the event of a configuration mismatch. This can happen if one server group configuration is reset, or changes in server group configurations are not communicated to the partner server group. Contact DataCore Technical Support for assistance. |
Partner not present |
Destination (Standby side) |
Partner server is not available. Check the partner server. |
Local server off-line |
Source (Active side) |
Local server is not available. Check the local server. |
Replication configuration mismatch |
Source or Destination |
May occur in a remote replication if the service is stopped on one server group and configuration changes are made on the partner, or if the partner is offline and configurations changes occur such as a forced split. Check the partner server. Contact DataCore Technical Support for assistance. |
Failed to write data to the offline buffer (active side when offline initialization is occurring) |
Source (Active side) |
May occur during the offline initialization process if there is a problem with the offline buffer. Check the buffer. |
General failure |
Source or Destination |
Check the Event Log for more information. |
Transfer status is the status of the virtual disk data being transferred to the destination.
Transfer status is displayed in:
o The Virtual Disk Details page>Replication tab (Transfer Status field)
o The Virtual Disks List (Abbreviated status displayed in the Status column; complete status is displayed in the Replication Status column in Advanced View.)
Status |
Description |
Failed (Communications Failure) |
Unable to connect to the destination (standby) server. Check the Event Log for more information pertaining to the communications failure. |
Failed (Destaging Failure) |
Connected to the destination (standby) server, but data is not being destaged. Check the Event Log for more information pertaining to the destaging failure. |
Healthy |
The data stream is being monitored for data and transferring as necessary. This is a normal working status. |
Pausing |
This is a transitory state and the data transfer is in the process of stopping. |
Resuming |
The data transfer is starting after being paused. This status occurs while the pending files are queued for transfer. |
Stopping |
The data transfer is being stopped. This state occurs while the pending transfers are being cancelled. |
Stopped |
The data transfer is disabled. This state occurs when the transfer is paused. |
Time lag |
When there is more than one file waiting to be transferred, the time lag is also displayed in hours, minutes, and seconds, such as Active (00:05:25 time lag). The time lag (or latency) is an estimation of the amount of time required for the destination to receive the current buffered data transmissions. |
Unknown |
This state could occur on the destination (standby) server, when there is no connection between the replication groups. |
Logging data changes can impact replication performance.
Also, if the server restarts for any reason, replications in this
status will go into full re-initialization after restart.