BackupHow

Introduction

• Backup How page allows users to control the backup process for the backup set.
• The left hand panel allows users to change backup timeouts and notification parameters.
• The right hand panel allows users to change backup parameters that impact the backup window.

All parameters except Notification parameter have default values. The default values will work for most backup set configurations. It is important to look at the backup reports for a few backup runs before changing these values.

It is important to set Notification parameter to the email address(es) of the Amanda administrator. Amanda backup run notifications are sent to the email address. ZMC users can also look at the contents of backup run notification in the Report Summary page.

After changing the parameters, users should save them by clicking "Save" button before going to another page. All changes will affect the next backup run. Parameters can be changed even when a backup run is in progress and the change will not have impact on the active backup run.

If the backup run has not been activated (or scheduled), the next page for the users should be Backup Activate page.

WARNING: Users should not modify the parameters directly in the Amanda configuration file and modify using ZMC at the same time. 
Before modifying Amanda configuration file directly, users should log out of their ZMC session.

Time Outs & Notification Parameters

Mail Address 

• • Email address of Amanda backup administrator.
  • The Mail user agent (MUA) such as Mail should be configured on the Amanda server. ZMC does not install or configure the MUA.
  • This email address can be different from the email address set in Admin page for a particular User.
  • This is an optional parameter. By default, no mail notification is sent. ZMC provides content of the notification in the Report Summary page for the backup set.The Mail user agent (MUA) such as Mail should be configured on the Amanda server.

Backup Estimate Time Out 

• • Amanda backup process involves estimation of backup size for each directory configured in the backup set.
  • This is the first phase of backup process.
  • The time taken to perform the phase can be seen in the Monitor page.
  • The backup size estimation for all Amanda clients in the backup set is done in parallel.
  • Users can specify a time out by which each Amanda client has to respond with backup size estimate.
  • If the time out occurs, the Amanda client will not be backed up during the backup run. Amanda will perform a full backup for the directories in the client in the next backup run.
  • This time out has to be adjusted for mobile clients, clients with limited network bandwidth, and clients with large amounts of data to be backed up.
  • The time out is applicable for all clients in the backup set.

Verification Time Out 

• • ZMC allows users to verify configuration of Amanda client in Verify Client page.
  • Verification Time out controls the time for which verification tool waits for the client to respond to verification requests.
  • The time out has to be adjusted for mobile clients and clients with limited network bandwidth.
  • If time out expires, the verification of the client fails.
  • This time out has no impact on the backup process.
  • The time out is applicable for all clients in the backup set.

Data Time Out 

• • This time out determines the amount of time the Amanda server will wait for the client to respond to the backup request.
  • If data time out occurs for a client, the backup of all directories for the client is not done in the backup run. The directories in the client will be backed up in the next backup run.
  • The time out has to be adjusted for mobile client and clients with limited network bandwidth.
  • The time out is applicable for all clients in the backup set.

Performance Parameters

Media Utilization 

• • This parameter detemines the order in which the completed backup images of a directory is moved from holding disk to the backup media. Only backup images that are completed in the holding disk are considered.
  • The ordering of the images can help in better utilization of backup media.
  • Options are:
    • First: Default:First in - first out.
    • Firstfit: The first backup image that will fit on the current media volume.
    • Largest: The largest backup image first.
    • Largestfit: The largest backup image that will fit on the current media volume.
    • Smallest:The smallest backup image first.
    • Last: Last in - first out.

Parallel Backups 

• • Number of parallel data backups that are perfomed from the Amanda client to the server holding disk in a backup run.
  • The default value is 10.
  • The number of parallel backups to the holding disk depends on
    • CPU and network resources on the Amanda server
    • Number of holding disks configured to allow parallel writes of the data
    • Network configuration between Amanda server and Amanda client

Backup Order 

• • The users can specify the priority order of each of the parallel backup process.
  • This is a method assign an Amanda client directory to a parallel backup process running on the Amanda server.
  • The number of parallel backup process is determined by the value of "Parallel Backups" field.
  • The possible option choices and what they mean is indicated below:

s -> smallest size

S -> biggest size

t -> smallest time

T -> biggest time

b -> smallest bandwidth

B -> biggest bandwidth

Try "BTBTBTBTBTBT" if the user is not holding disk constrained

Example 1 :
A string like "sssS" which represents the priority order for four parallel backups indicates that

three dumpers will seek smallest size hosts 
while one dumper will seek the biggest size host to backup.

Example 2 :
A string like'BbsTt'indicates there are five parallel backup process of which
One     backup process(B) is looking for the Biggest Bandwidth occupying backups.
Another backup process(b) is looking for the smallest Bandwidth occupying backup.
Another backup process(s) is looking for the smallest size backup.
Another backup process(T) is looking for biggest Time occupying backup.
Another backup process(t) is looking for smallest Time occupying backup.

TIP: Increasing the parameter will improve backup window size.

Parallel Backup Clients 

• • Number of parallel backups perfomed from an Amanda client.
  • The default value is 1 (Backups of all directories in a client is done sequentially)
  • If an Amanda client has sufficient CPU and network resources, multiple directories from the client can be backed up in parallel.

Holding Disk Threshold 

• • When there is a media error during a backup run, the backup images are stored in holding disk.
  • Amanda allows recovery from holding disk and backup media.
  • When holding disk falls below a threshold size (the value of this parameter), the Amanda does only incremental backups to conserve holding disk space.
  • 20% value means Amanda will only do incremental backups when holding disk(s) free space falls below 20%.

Auto Flush 

• • This parameter determines whether Amanda should flush the backup images from the holding disk to the backup media before a backup run.
  • The default value is Yes.
  • Users can monitor this activity in the ZMC Monitor page.