nather@utastro.UUCP (Ed Nather) (08/04/85)
We have been running Unix 4.2bsd for a *long* time now, with very high
load averages every day. I guess it was inevitable, but strange effects
on many working programs have been traced to a common cause:
/dev/null is full, and is overflowing!
Anybody seen this problem before? Can anyone help?
--
Ed Nather
Astronomy Dept, U of Texas @ Austin
{allegra,ihnp4}!{noao,ut-sally}!utastro!nather
nather%utastro.UTEXAS@ut-sally.ARPAdsn@tove.UUCP (Dana S. Nau) (08/05/85)
In article <2586@ut-sally.UUCP> crandell@ut-sally.UUCP (Jim Crandell) writes: >> >> /dev/null is full, and is overflowing! >> >> Anybody seen this problem before? Can anyone help? > >The solution apparently is not straightforward, else someone surely would >have discovered it by now. Try emptying the bit bucket. -- Dana S. Nau, Computer Science Dept., U. of Maryland, College Park, MD 20742 ARPA: dsn@maryland CSNet: dsn@umcp-cs UUCP: {seismo,allegra,brl-bmd}!umcp-cs!dsn Phone: (301) 454-7932
israel@tove.UUCP (Bruce Israel) (08/05/85)
In article <489@utastro.UUCP> nather@utastro.UUCP (Ed Nather) writes: >We have been running Unix 4.2bsd for a *long* time now, with very high >load averages every day. I guess it was inevitable, but strange effects >on many working programs have been traced to a common cause: > > /dev/null is full, and is overflowing! > >Anybody seen this problem before? Can anyone help? Yeah, we had it and discovered the solution quite by accident. What happened was that one of our staff people tried to empty the bit bucket. And how do you empty the bit bucket? Obviously into /dev/null. So he did a 'cat /dev/null >>/dev/null'. After he cleaned up the mess (it went all over the floor), he found that it hadn't solved it yet, and the bit bucket was now twice as full. Being a pretty ignorant staff member, he kept on trying it. Eventually the weight of all the one bits was such that /dev/null collapsed onto itself and became a small black hole. We spoke to the physics dept. and found that it requires 2.73 x 10**42 one bits to reach critical mass (of course as everyone knows, zero bits don't weigh anything and so are absolutely worthless in this procedure). Anyway, now our /dev/null is a black hole and we never need to empty it. Currently, one of our hackers is building a device driver so that we can run mknod to make a black hole immediately without having to go thru the above, long, very messy procedure. Our first test of it will be to install it in place of /usr/spool/news/net/flame/. If anyone else is having this problem, I'd be glad to 'uucp' our /dev/null file to your system. -- Bruce Israel seismo!umcp-cs!israel (Usenet) israel@Maryland (Arpanet)