Apps are increasingly using more than 1024 file descriptors. See discussion in several distro bug trackers, e.g. https://bugs.launchpad.net/bugs/663090 https://issues.rpath.com/browse/RPL-2054 You don't want to raise the default soft limit, since that might break apps that use select(), but it's safe to raise the default hard limit; that way, apps that know they need lots of file descriptors can raise their soft limit without needing root, and without user intervention. Ubuntu is doing this for 11.04 by changing include/asm-generic/resource.h: - [RLIMIT_NOFILE] = { INR_OPEN, INR_OPEN }, \ + [RLIMIT_NOFILE] = { INR_OPEN, INR_OPEN*4 }, \ They chose to do this with a kernel change because they have a policy of not changing kernel defaults in userland. While 4096 might not be enough for *all* apps, it seems to be plenty for the apps I've seen lately that are unhappy with 1024.
Send it to lkml, please. CC me and anyone else who might be interested.
Created attachment 52812 [details] Raise default hard ulimit on number of files to 4096 Submitted on lkml