topic Re: cifs.tcp_window_size in Network and Storage Protocols

cifs.tcp_window_size

jmckenna — Thu, 05 Jun 2025 07:18:30 GMT

I have read what is on wiki and also on kb. Along those lines I have also discussed with support changing this setting from 17520 (default setting) to 64240 to improve performance. I need to know if anyone has run into problems due to changing this or if you have had great success with making this change.

Re: cifs.tcp_window_size

rtriana — Wed, 17 Feb 2010 17:44:48 GMT

I have always made it a practice to increase this option from the default of 17520 to the recommended (per kb article and other documentation) to 64240. This can improve large write transfers. In any case, windows can "slide" to the appropriate value. If you leave it at default, it can never be larger than 17520. But at 64240, it can "slide" down. I've never heard or experienced any adverse effect from setting this option to 64240. And years ago, I had a copy of Network General Sniffer report that graphed the positive improvement of this setting at 64240 as compared to the default 17520.

This option change will requre a cifs terminate/restart or reboot in order to take effect immediately.

Rick

Re: cifs.tcp_window_size

jmckenna — Wed, 17 Feb 2010 18:28:40 GMT

Thank you. That helps.

Regards,

Jeff