Article ID: 8022
Reviewed: 2019-01-31

Product Version:
AhsayCBS: 8.1 to 8.x
OS: All platforms

After upgrading the backup server from version 6 to 8.1 or above, how do I run a Cyclic Redundancy Check (CRC) for legacy backup set that was created in version 6?

Steps:
To perform a Cyclic Redundancy Check (CRC) for a backup set, you can use the RunSingleUserRebuild.do API with the "CheckCrc" option enabled:

Note: This article assumes that the reader has basic knowledge on JSON (JavaScript Object Notation).

Parameters of RunSingleUserRebuild.do:

Key	Type	Description
SysUser	String	Username of AhsayCBS system account with Admin or API Role (mandatory field)
SysPwd	String	Password of AhsayCBS system account with Admin or API Role (mandatory field)
LoginName	String	Username of the corresponding backup account (mandatory field)
Owner	String	Owner of the corresponding backup account
BackupSetID	String	Backup set ID of the corresponding backup set to be rebuild
CheckCRC	Boolean	Enable or disable Cyclic Redundancy Check

Example API call:

http://cbs_hostname/obs/api/json/RunSingleUserRebuild.do

{
"SysUser":"system",
"SysPwd":"system",
"LoginName":"username",
"BackupSetID":"1449711651766",
"CheckCrc":"Y"
}

Administrator can uses application such as the WizTools.org RESTClient (this is a 3rd party tool used as an example, you can use any other application as desired) to test on the above API call:

1. Start the RESTClient by executing the downloaded jar file.
   
   
2. Select POST as the HTTP method.
   
   
   


3. Select the Body tab, then click the drop down menu just under it and choose String body.
   
   
4. For the URL field, enter the following:
   
   http://cbs_hostname/obs/api/json/RunSingleUserRebuild.do
   
   Where cbs_hostname is the hostname or IP address of your AhsayCBS server.
   
   
5. For the String body, enter the following:
   
   {
   "SysUser":"system",
   "SysPwd":"system",
   "LoginName":"username",
   "BackupSetID":"1449711651766",
   "CheckCrc":"Y"
   }
   
   Where 'system' and 'system' is the login credentials of an AhsayCBS admin account with Admin or API role, 'username' is the login name of the corresponding backup account, '1449711651766' is the ID of the backup set to be rebuild, with CRC enabled.
   
   
6. Click on the 'Go' button beside the URL.
   
   

The RunSingleUserRebuild.do will return status as 'OK' if the CRD job is started successfully. Now, to check on the progress of a CRC job, login to AhsayCBS console, select Backup / Restore Logs:



Select Activities Log, when the rebuild job is started the following log entry can be found:

Timestamp	Login Name	Owner	Type	Message
	...	...	...	...
YYYY-MM-DD hh:mm:ss	username		RoutineJobInfo	Rebuild-username Starting single user rebuild

When the rebuild job is completed, the following log entry can be found:

Timestamp	Login Name	Owner	Type	Message
	...	...	...	...
YYYY-MM-DD hh:mm:ss	username		RoutineJobInfo	Rebuild-username [SingleBackupSetRebuild] Finished single backup set rebuild. User='username' Owner='' Backup Set='BackupSet(backupset_id)' DataSize(compressed)=size DataSize=size DataFileNo=number RetentionSize(compressed)=size RetentionSize=size RetentionFileNo= number

Note: Note that a Cyclic Redundancy Check can only be started when there is no backup job running (of the corresponding backup set).

The time taken to complete the CRC job depends on number of factors such as the number of files / folders in the backup set(s), the number of backup sets, the hardware specifications of your AhsayCBS server such as the disk I/O and CPU performance, and if there are other resource intensive jobs running.

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