Tuning FreeBSD

[Daniel Gerzo]

Hello Lisa,

Saturday, August 19, 2006, 10:35:29 PM, you wrote:

> Hi Folksm

> I'm getting these on a FreeBSD 5.3 box:

> Aug 19 15:46:32 radius sm-mta[12850]: k7JJk1rt012776: SYSERR(UID0): fill_fd:
> disconnect: cannot open /dev/null:
>  Too many open files in system
> Aug 19 15:46:40 radius kernel: kern.maxfiles limit exceeded by uid 0, please
> see tuning(7).
> Aug 19 15:46:40 radius kernel: kern.maxfiles limit exceeded by uid 0, please
> see tuning(7).
> Aug 19 15:46:35 radius sm-mta[12784]: k7JJk7F0012784: SYSERR(UID0): queueup:
> cannot create queue file ./qfk7JJk
> 7F0012784, euid=0, fd=-1, fp=0x0: Too many open files in system

> I checked, and the system shows:

> radius# sysctl kern.maxfiles
> kern.maxfiles: 1416
> radius# sysctl kern.maxusers
> kern.maxusers: 43

> I googled and read that kern.maxfiles is dependent upon kern.maxusers and
> that I shou;d raise maxusers which I tried to do via sysctl:

I don't think that this is really required. Just raise the
kern.maxfiles sysctl if you really need to do so.

I would rather search for the reason why I need to allow kernel to
open such many number of files. Allowing it to open too many files
can lead to a Denial of Service.

> radius# sysctl -w kern.maxusers=50
> sysctl: oid 'kern.maxusers' is a read only tunable
> sysctl: Tunable values are set in /boot/loader.conf

> My /boot/loader.conf is a zero byte length file.

That is not problem. There is no /boot/loader.conf by default (IIRC)
although there is /boot/defaults/loader.conf

> How can I fix this too many open files problem?

> Thanks,

> Lisa Casey

-- 
Best regards,
 Daniel                            mailto:danger at FreeBSD.org