Perche ricevo messaggi di errore del log di Red Hat Enterprise Linux come ad esempio "INFO: task <process>:<pid> blocked for more than 120 seconds"?

Issue

• Si ricevono messaggi di errore nel log di Red Hat Enterprise Linux 5 o 6 come i seguenti:

INFO: task syslogd:2643 blocked for more than 120 seconds.  
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.  
syslogd D ffff81000237eaa0 0 2643 1 2646 2634  
(NOTLB)  
ffff8101352c3d88 0000000000000086 ffff8101352c3d98 ffffffff80063ff8  
0000000000001000 0000000000000009 ffff81013d2c57e0 ffff810102ac1820  
0000340b30708992 0000000000000571 ffff81013d2c59c8 000000010000089f  
Call Trace:  
[<ffffffff80063ff8>] thread_return+0x62/0xfe  
[<ffffffff88036d8a>] :jbd:log_wait_commit+0xa3/0xf5  
[<ffffffff800a1ba4>] autoremove_wake_function+0x0/0x2e  
[<ffffffff8803178a>] :jbd:journal_stop+0x1cf/0x1ff  
[<ffffffff8002ff40>] __writeback_single_inode+0x1e9/0x328  
[<ffffffff800e1464>] do_readv_writev+0x26e/0x291  
[<ffffffff800f3d9d>] sync_inode+0x24/0x33  
[<ffffffff8804c36d>] :ext3:ext3_sync_file+0xc9/0xdc  
[<ffffffff8005073a>] do_fsync+0x52/0xa4  
[<ffffffff800e1ce9>] __do_fsync+0x23/0x36  
[<ffffffff8005e28d>] tracesys+0xd5/0xe0