In the detailed statistics window of the SQL transaction log backup, you can examine the overall statistics of logs backup (child job), as well as per-VM information.
Overall statistics on log backups for all VMs included in SQL Server image-level backup job (‘parent’) is displayed in the upper part of the statistics window.
The Last period (all VMs) section contains statistical data for selected session of this image-level backup job.
In the Databases column, you can view the following information:
- Protected – number of databases that were backed up at least once during the last session
- Unprotected – number of databases that failed to back up during the last session
- Excluded – databases excluded from processing. This may be due to any of the following reasons: registry key value (list of exclusions), database status is Offline, database recovery model is set to Simple, database is read-only, database was deleted after the latest full backup.
Unprotected databases do not comprise Excluded, as they have different reasons for being non-processed
In the RPO column, you can view the following information:
- SLA value – how many log backup intervals completed in time with successful log backup (calculated as % of total number of intervals)
- Misses – how many intervals were missed (number of intervals)
- Max delay – actual difference between configured log backup interval and time actually required for log backup. If exceeded, a warning is issued.
In the Status column, the following information is displayed (per job): number of VMs processed successfully, with warnings or with errors.
The Latest session section includes the following information for the selected VM for the latest log processing interval:
- Duration – duration of log shipment from guest to repository by now since the start of current log processing interval
- Bottleneck – the operation with greatest duration in the last completed interval; this can happen due to the following:
Reason (displayed name)
Saving .BAK files to a temporary location on VM guest file system
Uploading log files to log shipping server
Saving files to target repository
- Read — amount of data read from temporary folder on VM guest
- Transferred – amount of data transferred to target repository
The Last period section includes the following statistics of log backups per VM for the latest sequence of log processing intervals (that is, log backup job session).
- The RPO column includes statistics on log processing interval (calculated as described above)
- The Sessions column includes statistics of log backups per VM, calculated as follows:
- Success – number of intervals when all database logs were backed up successfully
- Warning – number of sequential intervals with failed log processing (if not more than 4 intervals in a sequence)
- Errors – number of sequential intervals with failed log processing (more than 4 intervals in a sequence)
- The Duration column includes the following information:
- Average – average duration of log data transfer (through all intervals in the session)
- Max – maximal duration of log data transfer (through all intervals in the session)
- Sync interval – duration of periodic intervals specified for log backup in the parent job settings (default is 15 min)
- The Log size column includes the following information:
- Average – average amount of data (through all intervals) read from VM guest
- Max – maximal amount of data (over all 15-min intervals) read from VM guest
- Total – total amount of data written to repository
To filter out the corresponding actions, use the Errors, Warnings and Success filter buttons.
Statistics on transaction log processing is updated periodically, simultaneously for VM and for the log backup job.