What Factors affect Restore Speed (2617)
AhsayOBS / AhsayACB / AhsayOBM: Pre-220.127.116.11
OS: All platforms
This document contains the information on factors that can affect speed of a restore job.
Stages of a restore job are outlined as follow:
1. Connection from the client to the backup server is established.
2. Restore file list downloaded from the backup server.
3. Create the directory path for the restoration (if necessary).
4. Data are downloaded from the backup server.
5. Merging of delta files (if necessary).
6. Merging of combined delta file with full file.
7. Restore is declared completed.
Factors that can affect the speed of a restore at different stages of the job:
Internet connection speed
Check on the speed of the connection between the AhsayOBM / AhsayACB client and the AhsayOBS server.
Check if the restore job is being performed over a Local Area Network (LAN) or a Wide Area Network (WAN) environment.
Check on the hardware specification of the client computer and backup server computers (RAM available, processor speed), are the resource sufficient for the restore operation.
Check if the CPU usage is high during the restoration.
For computer running on Windows, you can view the CPU usage with the Windows Task Manager.
For computer running on Linux / Mac OS X, you can view the CPU usage with the command:
If the CPU usage is constantly maxed out during the restoration, it may suggests that the CPU power of the machine is insufficient for the restore operation
I/O utilization and location of the user home volumes
For AhsayOBS with 'local' user home (e.g. locally attached disk):
Check on the local disk I/O performance of the AhsayOBM / AhsayACB client machine, as well as the AhsayOBS server machine.
Check on the local disk I/O utilization of the AhsayOBM / AhsayACB client machine, as well as the AhsayOBS server machine.
For computer running on Windows, you can view the I/O utilization with the Windows Performance Monitor.
For computer running on Linux / Mac OS X, you can view the I/O utilization with the command:
If the I/O utilization of the disk in concern is high during the restore, consider performing the restore a an alternate time.
The commands above will only works for machine with local partition.
For AhsayOBS with remote user home (e.g. network shared path):
Check on the I/O performance of the Network Attached Storage (NAS) or Storage Area Network (SAN).
Check on the I/O utilization of the Network Attached Storage (NAS) or Storage Area Network (SAN).
Location of the restore destination (local / network drive)
Check if the restore destination is located locally, or over a network.
If the restore destination of the restore job is set over a network, the restore speed may be affected depending on the network traffic and speed.
Restore source data size (number of files and size of files)
How many files are selected for the restore?
If a large number of files (e.g. over a million files) are selected for the restore, consider to edit the Java heap size (memory setting) available to the client application.
Number of delta to be merged
How many delta files are being merged?
Delta merging is a resource intensive procedure. Thus, the speed of a restore can be greatly affected if the number to delta files to be merged is large.
Amount of memory (Java heap size) available
Check on the Java heap size setting, modify the setting if the currently allocated size is insufficient for the restore operation.
Number of backup / restore job connecting to the AhsayOBS server
Check on the number of backup / restore job connected to the AhsayOBS during the restoration.
If a high number of backup / restore job is connected to the AhsayOBS server during the restore operation, consider performing the restore at another time.
Number of system routine job running on the backup server
Check on the number of resource intensive system job that is running when the restoration is performed (e.g. Rebuild User Storage, Cyclic Redundancy Check (CRC) Checking).
If a high number of resource intensive system job is running when the restore job is performed, please consider performing the restore at another time.