What to do when I get “mysqld dead but subsys locked” in my amazon ec2 micro instance?
Fatal error: cannot allocate memory for the buffer pool


You have only 1GB of RAM?  What is the value of innodb_buffer_pool_size; it should not be more than, say, 50M.

What changes did you make to my.cnf?  There may be other things to decrease.  (Or you could get more RAM.)

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If you have more than just MySQL in that 1GB, it may really be impractical to have such a tiny VM.  Either split into to VMs, one for MySQL and one for app, or get get a bigger VM.