MAMP PRO crashes; MySQL will not start on reboot

Question

Today at work my computer randomly froze/crashed. On reboot MAMP refuses to start mysql and I can't figure out why. There are definitely no other mysql processes running; I’ve checked several times. So, the `killall -9 mysqld` is not the solution. I’ve actually completely re-installed MAMP, also. This is what seems to be the important part of my MySQL log, but I’m not very seasoned in reading these things, so maybe the answer is right in front of me. ``` 140527 15:06:58 mysqld_safe Starting mysqld daemon with databases from /Library/Application Support/appsolute/MAMP PRO/db/mysql 140527 15:06:58 [Warning] Using unique option prefix key_buffer instead of key_buffer_size is deprecated and will be removed in a future release. Please use the full name instead. 140527 15:06:58 [Warning] Setting lower_case_table_names=2 because file system for /Library/Application Support/appsolute/MAMP PRO/db/mysql/ is case insensitive 140527 15:06:58 [Note] Plugin 'FEDERATED' is disabled. 140527 15:06:58…

Accepted Answer

PREFACE: This sounds bad, but please be sure to read everything in this answer before acting. You can’t break things worse by taking your time. Read each step & hopefully this will be clear enough for you to follow & get your MySQL database server in MAMP Pro up and running again.

So, it seems like your InnoDB databases crashed. Not the app itself. The key is here in the log:

```
140527 15:06:58 InnoDB: highest supported file format is Barracuda.
InnoDB: Log scan progressed past the checkpoint lsn 791075520
140527 15:06:58  InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
InnoDB: Doing recovery: scanned up to log sequence number 791076717
InnoDB: Database page corruption on disk or a failed
InnoDB: file read of page 8402.
InnoDB: You may have to recover from a backup.
```

And it looks like you are using MAMP PRO over here:

```
/Library/Application Support/appsolute/MAMP PRO/db/mysql
```

So the question is, do you have a backup of the MAMP Pro databases? Either via `mysqldump` or something else? Do you have other InnoDB databases in your MAMP install?

Also, you say you were able to run `mysqldump`, but it’s really not possible of the database crashed. So I am assuming when you ran `mysqldump` that was another, separate install of MySQL on your system. The MySQL binaries such as `mysqldump` in MAMP or MAMP Pro are not the same as the systemwide `mysqldump`. They are two 100% different installs. You can check which `mysqldump` is being used by typing in this command:

```
which mysqldump
```

To see the full path of what you believe you were using. The MAMP install of `mysqldump`—and other related binaries—is located here:

```
/Applications/MAMP/Library/bin/
```

And to run it directly without modifying your `$PATH` value (a whole other thing) is to run it like this:

```
/Applications/MAMP/Library/bin/mysqldump
```

PLEASE READ CAREFULLY: Please note the advice I am giving you below is me presenting every way I would deal with a situation like this. If the InnoDB database is not important, just do my first suggestion of trashing the InnoDB specific DB files. If you have a `mysqldump` backup, do the same thing but recover the `mysqldump` backup.

Also, InnoDB is not a default storage engine. You have to go out of your way to set that. The default is MyISAM. Any new DB created in MySQL will be MyISAM. So this will help you. You need to put on your thinking cap an figure out which databases have InnoDB storage engines set. If you say you have 25 but only 1 has InnoDB, easy solution. But also if you have 25 databases, you should get into the habit of making regular `mysqldump` backups. If you had backups, this would be a headache but a straight forward thing to solve.

ONE OPTION: Delete the corrupted InnoDB stuff & recover from a `mysqldump` backup.

The first thing I would do if I were you is backup the `mysql` directory in `/Library/Application Support/appsolute/MAMP PRO/db/` so you can at least have a backup of the corrupted files just in case.

Then I would delete the following files:

```
/Library/Application Support/appsolute/MAMP PRO/db/mysql/ib_logfile0
/Library/Application Support/appsolute/MAMP PRO/db/mysql/ib_logfile1
/Library/Application Support/appsolute/MAMP PRO/db/mysql/ibdata1
```

Those are InnoDB specific files. Delete them and then attempt to start MAMP again. It should come up. But any InnoDB database in MAMP will be in some “zombie” state. You should delete those databases & recreate from backup. Or from scratch if you can.

ANOTHER OPTION: Try to get the MySQL server up & running again with `innodb_force_recovery`.

Now on the offhand chance you need to recover that DB, you can run attempt to set a `innodb_force_recovery` as described here.

For MAMP Pro it seems you can edit your MySQL configuration file as per these instructions:

- Start MAMP Pro.

- Stop the MAMP Pro server if it is running.

- Select File -> Edit Template -> MySQL my.cnf

- An editor window appears.

- If a warning message appears confirm with OK.

- Find the section "[mysqld]"

- Beneath the last line of this section add this line: `innodb_force_recovery = 1`

And as the MySQL documentation explains, this is strictly to get the database up and running so you can make a backup via `mysqldump`:

In such cases, use the innodb_force_recovery option to force the InnoDB storage engine to start up while preventing background operations from running, so that you can dump your tables.

Now there are about 6 different values for `innodb_force_recovery` but you should really only attempt with `1` for now. If you want to attempt each of the 6, here is a breakdown:

1 (SRV_FORCE_IGNORE_CORRUPT)

Lets the server run even if it detects a corrupt page. Tries to make SELECT * FROM tbl_name jump over corrupt index records and pages, which helps in du…

MAMP PRO crashes; MySQL will not start on reboot

Solution

Problem