Increase TCP Window size to improve Backup & Restore performance

Issue:

Slow Backup & Restore performance in high latency networks such as WAN and Cloud with Application ingesting data via DDBoost protocol to PowerProtect DD.
 

Root Cause:

Lower value of TCP Window size that is (socket send and socket receive buffer size) configured for DDBoost TCP socket connection with PowerProtect DD.

In Linux Clients default value of the following Network kernel Settings is 212992 Bytes (208KB):

• net.core.wmem_max
• net.core.wmem_default
• net.core.rmem_max
• net.core.rmem_default

So, if above Linux network kernel setting hasn’t been changed, above values are selected for send and receive buffer for DDBoost Socket connection with PowerProtect DD.

In Linux, socket send buffer size is minimum of size requested and "net.core.rmem_max". Similarly, socket receiver buffer size is minimum of size requested and "net.core.wmex_max".
 

Resolution:

Increase TCP Window size that is (socket send and socket receive buffer size) via sysctl command on Linux Clients to 1MB for "net.core.rmem_max" and 2MB for "net.core.wmem_max" by following the below example.

Example:

sudo sysctl -w net.core.rmem_max=1048576
sudo sysctl -w net.core.rmem_default=1048576

sudo sysctl -w net.core.wmem_max=2097152
sudo sysctl -w net.core.wmem_default=2097152

Note:

• These changes are only temporary and will not persist after a reboot. To make the changes permanent, add the sysctl commands to the system's configuration file, typically located at /etc/sysctl.conf
• Changing above settings may impact other Applications using TCP socket on same Linux client and it also increases kernel memory space used.

Applicable Versions:

All DDBoost client versions integrated with Linux Clients.

Applicable Versions:
All DDBoost client versions integrated with Linux Clients