Hi, (2010/11/13 6:25), My LinuxHAList wrote: > I saw in the logs: > kernel: INFO: task sadc:23936 blocked for more than 120 seconds. > kernel: "echo 0> /proc/sys/kernel/hung_task_timeout_secs" disables > this message. This message is useless to solve problem without Linux developer. Every high load and small trouble machine represents this message. It seems hard disk trouble or memory error. If your disk has write-error happened, retry sequences will be run at, firmware(in HDD), physical driver(in Linux), Logical driver(in Linux scsi) and swapd (in application). Over of 120sec of total these retry sequences, the kernel prints this message in console. you have to change some hardware (hard-disk, memory, cpu, mother-board.) HDD errors and memory errors sometimes be fixed in automatically, You can't reproduce this errors again. > Reading later release of kernel did not mention this bug. Upstream/CentOS community will not release this software fix. :-) Tsuyoshi