[Nut-upsuser] Runaway apcsmart process

[Bill Arlofski]

On several occasions I have seen the apcsmart process runaway using 100% CPU
while filling my syslog partition by logging the following syslog entries at
an incredible rate. I have seen up to 21,800 log entries PER SECOND of the
following nature:


--[snip]--
Jun 25 10:06:38 servername apcsmart[4012]: Communications with UPS lost:
Communications with UPS lost - check cabling
Jun 25 10:06:38 servername apcsmart[4012]: smartmode: ser_send_char failed:
Input/output error
Jun 25 10:06:38 servername apcsmart[4012]: smartmode: ser_send_char failed:
Input/output error
Jun 25 10:06:38 servername apcsmart[4012]: smartmode: ser_send_char failed:
Input/output error
Jun 25 10:06:38 servername apcsmart[4012]: smartmode: ser_send_char failed:
Input/output error
Jun 25 10:06:38 servername apcsmart[4012]: smartmode: ser_send_char failed:
Input/output error
Jun 25 10:06:38 servername apcsmart[4012]: smartmode: ser_send_char failed:
Input/output error
Jun 25 10:06:38 servername apcsmart[4012]: smartmode: ser_send_char failed:
Input/output error
Jun 25 10:06:38 servername apcsmart[4012]: smartmode: ser_send_char failed:
Input/output error
Jun 25 10:06:38 servername apcsmart[4012]: smartmode: ser_send_char failed:
Input/output error
Jun 25 10:06:38 servername apcsmart[4012]: smartmode: ser_send_char failed:
Input/output error
--[snip]--


There is nothing wrong with the cabling, and nut runs fine until this begins.
If I kill apcsmart and then restart the nut ups driver everything goes back to
normal for days or weeks or months at a time.

I am using nut v2.4.1-r1 on a Gentoo Linux system with a 2.6.27 kernel on an
AMD Athlon X2 64bit dual core system.

Any thoughts?  What other information can I provide to help diagnose and
hopefully solve this issue?

Thanks!

--
Bill Arlofski
Reverse Polarity, LLC
http://www.revpol.com/