Red Hat Bugzilla – Bug 40103
Slowly SCSI on a NCR53C876 cause high load
Last modified: 2005-10-31 17:00:50 EST
From Bugzilla Helper: User-Agent: Mozilla/4.0 (compatible; MSIE 5.0; Windows 95; DigExt) Description of problem: I got a RedHat Linux 7.0 running kernel 2.2.16, after upgrade to RedHat 7.1 kernel 2.4.2, the load average goes upper than normal, the System consumes all process power Running top, I can see: 12:41pm up 2:10, 2 users, load average: 17.62, 20.45, 17.06 51 processes: 45 sleeping, 6 running, 0 zombie, 0 stopped CPU0 states: 1.7% user, 98.10% system, 0.0% nice, 0.0% idle CPU1 states: 0.16% user, 99.0% system, 0.0% nice, 0.0% idle How reproducible: Always Steps to Reproduce: 1. Install RedHat 7.1 on a equivalent machine Actual Results: All the system resources are consummed. Expected Results: Normal system activity. Additional info: Dual Pentium III 600Mhz Intel N440BX Motherboard 512Mb RAM, SCSI On Board NCR53C876 3 HDs SCSI, 1 Quantum QM39100TD-SW 9Gb, 2 Fujitsu 18Gb (MAE3182LP & MAE3182MP) ethernet: EtherExpress 10/100Mbits, 3COM 905b 10/100Mbits If I run in single mode and copy lot of data from one disk to other, or to same disk, I can see some pauses, I hope that this cause the load average to go higher, may be the driver is broken, actually, I'm using ncr53c8xx The computer also is a "router", it's job is to filter and forward packages from one ether device to other, I run ipchains for package filtering, cbq to shape speed for some clients (I tried to stop cbq and load average still high) and some shaper interfaces configured, squid, sendmail, and other minor process, but no one allocate lot of resources. All this scenario runs okay in RedHat 7.0, but after upgrade, the system goes slow, I think that the network traffic don't make difference, since, in single mode I got some pauses managing data.
Can you paste a "top" screen to this bug? (eg so we can see which processes eat the CPU) Or even the output of "ps waux" so we can see which processes are causing the high load?
Alternatively, we are working on an upgraded kernel with a newer NCR scsi driver, a recent snapshot of the RPM for that kernel can be found in the rawhide part of our ftp site.
Some hours after, the system was consumming 100% of resources, and the computer was inacessible, I need to reset. After this, I made more tests: - tried to use the sym53c876 modules - reboot and got system consumming 80% of resources after 30 minutes - tried to remove cbq and shaper modules - reboot and got system consumming 80% of resources after 30 minutes - downgrade to 2.2.16smp kernel from RedHat 7.0 disk - 45 minutes of uptime now, system at average of 10% Now my system look stable. But the problem still exists. I can't take a screen now because it's a production server and I can't reboot to kernel 2.4 and wait crash, but I saw nothing anormal in top command, just normal process using very low CPU, the sum of all process was bellow 50%. If it's a tip, the top process is squid, running at 10%-20% of CPU, may be him make all data traffic to the system goes to crash. There are any previsible problem with kernel downgrade ?
If you don't have hostile local users, 2.2.16 should be fine for most stuff. (only not for usb, but it doesn't look like you are using that ;)
We have an upgraded driver in rawhide which should fix this -> closing as fixed in rawhide. Using 2.2.16 is an alternative.
hi again. I made a upgrade to kernel 2.4.3-12enterprise for i686 from RedHat Errata. The problem persist. here is the header of top. 8:39am up 48 min, 1 user, load average: 0.85, 0.83, 0.64 82 processes: 81 sleeping, 1 running, 0 zombie, 0 stopped CPU0 states: 6.3% user, 67.2% system, 0.0% nice, 25.3% idle CPU1 states: 5.3% user, 65.3% system, 0.0% nice, 28.3% idle Mem: 512868K av, 499144K used, 13724K free, 56K shrd, 242120K buff Swap: 556012K av, 292K used, 555720K free 153496K cached PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND 1041 squid 16 0 19852 19M 1404 S 45.0 3.8 9:01 squid 826 netsaint 9 0 1088 1088 792 S 4.9 0.2 0:26 netsaint 14092 root 9 0 2444 2444 1980 S 3.1 0.4 0:00 sendmail 14047 root 10 0 2444 2444 1980 S 1.9 0.4 0:00 sendmail 549 root 9 0 1956 1952 1760 S 1.7 0.3 0:02 sendmail 13860 root 16 0 1028 1028 768 R 1.5 0.2 0:00 top 14011 root 10 0 2440 2440 1980 S 1.1 0.4 0:00 sendmail 13188 root 9 0 2428 2428 1964 S 0.5 0.4 0:01 sendmail 13293 root 9 0 2428 2428 1968 S 0.5 0.4 0:01 sendmail 14109 root 9 0 2420 2420 1988 S 0.5 0.4 0:00 sendmail 13114 apache 8 0 4016 4004 3592 S 0.3 0.7 0:00 httpd 14065 root 9 0 2476 2476 1932 S 0.3 0.4 0:00 sendmail 14106 root 9 0 2300 2300 1960 S 0.3 0.4 0:00 sendmail 14107 root 9 0 2312 2312 2052 S 0.3 0.4 0:00 sendmail 14112 netsaint 9 0 540 540 476 S 0.3 0.1 0:00 check_ping 6 root 9 0 0 0 0 SW 0.1 0.0 0:01 kupdated