Schedulers in supercomputers

LoadLeveler

http://www.ccs.ornl.gov/eagle/LL.html
http://www.bu.edu/tech/research/training/scv-software-packages/loadleveler/
http://kb.iu.edu/data/azvs.html

Cluster status	llstatus
List jobs in the queues/classes	llq
List information of classes/queues	llclass
Reservation check	llqres	This may or may not work. Probably you should command showres

PBS

pbsnodes

Moab

http://www.clusterresources.com/products/mwm/docs/a.gcommandoverview.shtml
http://www.clusterresources.com/products/maui/docs/16.1simulationoverview.shtml

mshow -a  # show available resources

Mysql error "InnoDB: Unable to lock ./ibdata1, error: 11"

Recently, there was a power outage in the lab. I did not shut down my machines before the power outage. After I restarted my Ubuntu, I could not start up Mysql. The error was:

InnoDB: Unable to lock ./ibdata1, error: 11
InnoDB: Check that you do not already have another mysqld process
InnoDB: using the same InnoDB data or log files.
InnoDB: Error in opening ./ibdata1

But I am 100% sure that no another mysqld process was running. After I searched on line, I found that I was not the only one encountering this error. See this post.
This post has an insight into this problem. It seems to be caused by NFS. Mysql is not installed on a local file system. It is installed on a remote file system which is mounted to other file systems by using NFS.

Solution
make a copy of the original files (ibdata1, ib_logfile0, ib_logfile1...).

mv ibdata1 ibdata1.bak
cp -a ibdata1.bak ibdata1
......