I created an AMI from my running EC2 Ubuntu instance. I then brought it up, and MySql is not running the same way on this copied instance.

1) Changes to my my.cnf file are not getting picked up.

2) I am unable to query my database as it gives me the following error:

ERROR 1286 (42000): Unknown table engine 'InnoDB'

I guess MySql is not configured correctly? I'm new to MySql, so can you tell me what I'm doing wrong please?

Thanks in advance.

  • Are you restarting mysql after each change in my.cnf? What's there in my.cnf? – rvs Jun 16 '11 at 18:20

Check /var/log/syslog for any errors that occurred during MySQL's startup. It may be that your /etc/mysql/my.cnf file includes a skip-innodb statement, which would disable InnoDB tables.

  • Unfortunately, it was not as straightforward as that. – cone Jun 16 '11 at 21:02

I learnt (after several hours of troubleshooting) that if something goes wrong in your setup, none of the settings are updated.

For eg. in my case,the replication was broken. However, Instead of

Slave_IO_Running: No
Slave_SQL_Running: No

Turning up as "NO", the name of the master host also didn't get updated, which I had changed in my .cnf file. Also, skip-innoDB was not set in my .cnf file, but innoDB was still not getting enabled. This led me to suspect that the problem was related to the .cnf file.

It turned out, however, to be two separate things.

InnoDB could not come up due to a shortage of memory. The memory I was allocating was more than the new EC2 instance offered. This is a lesson creating images : pay attention to the size of the instance you are creating.

The second problem was that replication was not coming up. This is because I had not:


And then appropriately modified:


I got the answer to this on another SF question:

Why is MySQL Replication so complicated?

Great guide posted as an answer there.

I got pointers to all this in my SQL log located in:


It had the following entries:

InnoDB: Error: cannot allocate 1048592384 bytes of

InnoDB: memory with malloc! Total allocated memory

InnoDB: by InnoDB 38079360 bytes. Operating system errno: 12

InnoDB: Check if you should increase the swap file or

InnoDB: ulimits of your operating system.

InnoDB: On FreeBSD check you have compiled the OS with

InnoDB: a big enough maximum process size.

InnoDB: Note that in most 32-bit computers the process

InnoDB: memory space is limited to 2 GB or 4 GB.

InnoDB: We keep retrying the allocation for 60 seconds...

InnoDB: Fatal error: cannot allocate the memory for the buffer pool

110616 18:41:58 [ERROR] Plugin 'InnoDB' init function returned error.

110616 18:41:58 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.

110616 18:41:58 [Warning] Neither --relay-log nor --relay-log-index were used; so replication may break when this MySQL server acts as a slave and has his hostname changed!! Please use '--relay- log=ip-xxxx-relay-bin' to avoid this problem.

110616 18:41:58 [ERROR] Failed to open the relay log 'xxxx' (relay_log_pos 251)

110616 18:41:58 [ERROR] Could not find target log during relay log initialization

110616 18:41:58 [ERROR] Failed to initialize the master info structure

I really hope this helps someone some day!

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.