DS-Client Buffer
Creation Date: October 14, 1997
Revision Date: January 11, 2010
Product: DS‑Client
Summary
The DS‑Client buffer is a temporary storage location on the DS‑Client computer. To change this directory, click
DS‑User > Setup > Configuration > Parameters tab. For more information, see
“Configuring the parameter settings”.
When the Use Buffer option is selected, backup files are transferred to the buffer location first, and then the backup/restore operation is performed (data is processed through the DS‑Client).
This minimizes the time that the LAN must support the additional backup/restore traffic. It is particularly useful if the DS‑Client's connection to the DS‑System is much slower than its connection with the LAN.
The DS‑Client buffer can also provide temporary storage as the database dump location for Microsoft SQL and Microsoft Exchange database backups (this avoids the need for extra disk capacity on network servers).
DS‑Client deletes all files from the DS‑Client buffer after each activity, regardless whether or not the operation was performed successfully.
Backup sets configured to use the DS-Client buffer automatically benefit from the Block-Level Resume feature (
“Block-Level Resume”).
Types of DS‑Client activities that use the DS‑Client Buffer
Use Buffer | Backup: Speeds up backup operations by copying files to DS‑Client buffer first (at LAN speed) and then transferring files to the DS‑System (at DS‑System connection speed). Minimizes time that the network resource is used for the backup operation. Restore: Speeds up restore operations by restoring files to the DS‑Client buffer first (at DS‑System connection speed) and then copying files to the network resource (at LAN speed). This minimizes the time that the network resource is used for the restore operation. |
Microsoft Exchange Server | The DS‑Client always copies the Microsoft Exchange Server database(s) to the DS‑Client Buffer first, and then transfers the files to the DS‑System. For extremely large Microsoft Exchange Server databases (that would require too much disk space), you can specify that backups be performed with the “DS‑Client Pipe” option. |
Microsoft SQL Server, Oracle Server | When performing backups/restores of Microsoft SQL Server or Oracle Server databases with the 'Dump to DS‑Client Buffer' option, database dump(s) are created on the DS‑Client Buffer and then transferred to the DS‑System. This provides disk space for database dumps on the DS‑Client computer and saves the need for extra disk capacity on the database servers. |
Best practices
Follow these recommendations to enable the DS-Client buffer to operate optimally:
• Ensure that sufficient disk capacity for your backup needs is available on the drive containing the DS‑Client computer's buffer directory. For example, to support the backup activities for SharePoint Online data, the DS-Client buffer must provide the storage capacity calculated based on the advanced parameters SharePointOnlineBackupBatchSize (in the Miscellaneous category) and MaxSessions (in the Performance category) and the largest possible size of files that are larger than 500 MB in SharePoint Online:
SharePointOnlineBackupBatchSize x MaxSessions x Largest file size
Arbitrary values are assigned below to provide an illustration:
• SharePointOnlineBackupBatchSize: value = 1
• MaxSessions: value = 2
• Largest possible size of files that are larger than 500 MB in your SharePoint Online Server: 10 GB
In this arbitrary example, the DS-Client buffer capacity required for SharePoint Online backup activities is 1 item per batch x 2 sessions x 10GB = 200 GB
• You must also make sure that the buffer storage location supports the same structure as the source. For example, if your DS-Client buffer is on a Linux file system, the maximum number of sub-directories allowed within a single directory is 32767. If you try to backup a path that holds more than this number of sub-directories using the DS-Client buffer, it will fail since it exceeds the maximum number of sub-directories allowed.
• Do not select the Use Buffer option with backup sets that have data on the DS‑Client computer. Use Buffer copies backup files to the DS‑Client buffer. From there, they are processed for backup by the DS‑Client. If the DS‑Client buffer directory is part of a backup set, problems may occur since the Backup may catch a loop that reads the same directories being copied for backup.
• To maximize the speed, provide enough credentials for all backup sets to access the DS-Client Buffer directory.
The DS-Client Buffer is also used by activities that access DS-Client Database to create temporary files for bulk insert (for optimization of processing). If a backup set is not assigned enough credentials to Create/Delete/Read/Write files in the DS-Client Buffer directory, bulk insert operations will fail and a regular insert is used instead.