This hangs on x64 centos linux 6.5 4gb ram, 2gb swap, 3ware raid card 9650se-4lpml
log from kernel messages
INFO: task sadc:1716 blocked for more than 120 seconds.
Not tainted 2.6.32-431.el6.x86_64 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
sadc D 0000000000000000 0 1716 1715 0x00000084
ffff8800379afdc8 0000000000000086 ffff8800379afd90 ffff8800379afd8c
ffff8800379afd88 ffff88011fc23280 ffff880028216840 0000000000000400
ffff880119c83058 ffff8800379affd8 000000000000fbc8 ffff880119c83058
Call Trace:
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INFO: task sadc:1716 blocked for more than 120 seconds.
Not tainted 2.6.32-431.el6.x86_64 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
sadc D 0000000000000000 0 1716 1715 0x00000084
ffff8800379afdc8 0000000000000086 ffff8800379afd90 ffff8800379afd8c
ffff8800379afd88 ffff88011fc23280 ffff880028216840 0000000000000400
ffff880119c83058 ffff8800379affd8 000000000000fbc8 ffff880119c83058
Call Trace:
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change the default value of vm.dirty_ratio and vm.dirty_background_ratio kernel parameters
vim /etc/sysctl.conf
vm.dirty_ratio = 5
vm.dirty_background_ratio = 5
sysctl -p