Ahsay Information: What Factors affect Backup Speed (2651)

Ahsay Information:

What Factors affect Backup Speed (2651)

Product Version:

AhsayOBS / AhsayACB / AhsayOBM: Pre-7.3.2.0
OS: All platforms

Description:
This document contains the information on factors that can affect speed of a backup job.

Stages of a backup job are outlined as follow:

1. Connection from the client to the backup server is established.
2. Pre-backup command is run (if necessary).
3. Shadow Copy set of the backup source is created (if available).
4. Remote file list downloaded from the backup server.
5. Data of the backup source is compared with the remote file list to compile the following file lists:

a. New file list
b. Modified file list
c. Deleted file list

6. In-file delta file is generated (if necessary).
7. Data are encrypted, compressed, and then uploaded onto the backup server.
8. Shadow Copy set of the backup source is removed (if necessary).
9. Post-backup command is run (if necessary).
10. Backup is declared completed.

Factors that can affect the speed of a backup 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 backup job is being performed over a Local Area Network (LAN) or a Wide Area Network (WAN) environment.

Hardware specification
Check on the hardware specification of the client computer and backup server computers (RAM available, processor speed), are the resource sufficient for the backup operation.

Check if the CPU usage is high during the backup.

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:

>top

If the CPU usage is constantly maxed out during the backup, it may suggests that the CPU power of the machine is insufficient for the backup 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:

>iostat 1

or

>vmstat 1

If the I/O utilization of the disk in concern is high during the backup, consider performing the backup job a an alternate time. Also, consider to add additional user home volumes, and then spreading the backup accounts onto the user home volumes evenly.

Note:
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 backup source (local / network drive)
Check if the backup source is located locally, or over a network.

If the backup source of the backup job is set over a network, the backup speed may be affected depending on the network traffic and speed.

Location of the temporary directory (local / network drive)
Check if the temporary directory specified for the backup set is located locally, or over a network.

If the temporary directory is specified on a network partition, the backup speed may be affected for backup type such as MS Exchange server backup, or MS SQL, depending on the network traffic and speed.

Backup source data size (number of files and size of files)
How many files are selected as the backup source?

Check if the backup source contain a large number of files within a small number of directories.

If the backup source contain a large number of files (e.g. over a million files), you may consider splitting up the backup set into multiple backup sets with a smaller number of files.

Also, alter the amount of memory available to AhsayOBM.

Number of delta to be generated
How many delta files are being generated, and their size?

The speed of a backup job can be affected if the number to delta files to be generated is large, or if the delta files to be generated is large.

Encryption setting
Check on encryption key length configured for the backup set in concern.

For AhsayOBM / ACB version after 5.5, backup data can be encrypted with key length of 256-bit, which may slow down the backup operation for machines with insufficient resource.

Local Copy module
Check if the Local Copy module has been enabled for the backup set.

For AhsayOBM version after 5.5, local backup data are compressed and encrypted, which may also slow down the backup operation for machines with insufficient resource.

Check if the Local Copy destination is located locally, or over a network (local / network drive).

If the Local Copy destination of the backup job is configured to a network partition, the backup speed may be affected depending on the network traffic.

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 backup 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 backup.

If a high number of backup / restore job is connected to the AhsayOBS server during the backup operation, please consider performing the backup 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 backup job 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 backup job is performed, please consider performing the backup at another time.