Kernel pty limit

Christopher Cowart ccowart at
Thu Nov 15 12:02:15 PST 2007


I went to open up a new shell to our login server (recently rebuilt from
Debian to FreeBSD) and found problems allocating a new pty. With a
256-pty limit, I'm surprised more people haven't had this problem. With
team of 8 SysAdmins, each leaving about 30 windows open in screen
sessions, 256 starts feeling a bit claustrophobic. 

I found a questions thread from January 2006 and these PRs:
standards/90896: not enough PTYs in the FreeBSD
kern/25866: [patch] more than 256 ptys, up to 1302 ptys.

The latter appears to have been kicking around since FreeBSD 4.3 (still

What can I do to help get that limit raised? Does anyone have a patch
against 6.2? If not, would anyone be interested in writing one?

Thanks for any help,

Chris Cowart
Lead Systems Administrator
Network & Infrastructure Services, RSSP-IT
UC Berkeley
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 825 bytes
Desc: not available
Url :

More information about the freebsd-questions mailing list