MySQL tables gone

diwljina · 07-27-2012, 11:46 AM

Hi!

I'm not sure if this is the right subforum, but here it is.

After automatic update of mysql, I lost all tables in a database. I can't see them from console or phpMyAdmin. But when I go to /var/lib/mysql there it is 300MB directory. What happend and how can I get this database back?

I tried repairing with mysqlcheck, but nothing happened.

Kustom42 · 07-27-2012, 11:48 AM

After upgrading MySQL you should ALWAYS do the following commands:

Code:

mysql_upgrade -uroot -p
mysqlcheck -Aro -uroot -p

That should update your mysql database so that it can read the other databases correctly

diwljina · 07-27-2012, 12:13 PM

Hi Kustom42 and thanks for your response!

Automatic update is performed by cPanel and I guess it executes that command after updates. Nevertheless, I just tried with those and still nothing. No tables. Perhaps it wasn't due to update, but I have no idea why this happened.

Any other suggestion?

Kustom42 · 07-27-2012, 12:17 PM

What is the output of

Code:

ls -al /var/lib/mysql/
mysql -uroot -p -Dmysql -e"SELECT * FROM information_schema.tables WHERE table_schema = 'YourDatabaseName';"

diwljina · 07-27-2012, 12:26 PM

Code:

 ls -al /var/lib/mysql/
total 30800
drwxr-x--x 26 mysql mysql     4096 Jul 27 11:53 ./
drwxr-xr-x 75 root  root      4096 Jul  3 05:19 ../
drwx------  2 mysql mysql     4096 Jul 27 11:54 cphulkd/
drwx------  2 mysql mysql     4096 Jul 27 11:54 eximstats/
drwx------  2 mysql mysql     4096 Jul 27 11:54 horde/
-rw-rw----  1 mysql mysql 18874368 Jul 27 10:57 ibdata1
-rw-rw----  1 mysql mysql  5242880 Jul 27 10:57 ib_logfile0
-rw-rw----  1 mysql mysql        0 Jul 27 10:57 ib_logfile1
drwx------  2 mysql mysql    12288 Jul 27 11:55 company_workpress/
drwx------  2 mysql mysql    12288 Jul 27 11:05 company_products/
drwx--x--x  2 mysql mysql     4096 Jul 27 11:55 mysql/
srwxrwxrwx  1 mysql mysql        0 Jul 27 11:08 mysql.sock=
-rw-r--r--  1 root  root         6 Jul 27 11:05 mysql_upgrade_info
drwx------  2 mysql mysql     4096 Jul  3 05:19 roundcube/

company_products is problematic database.

Second command gives nothing. Empty set.

Kustom42 · 07-27-2012, 12:37 PM

Quote:

Originally Posted by diwljina

company_products is problematic database.

Second command gives nothing. Empty set.

Did you replace the 'YourDatabaseName' with company_products?

What does

Code:

mysql -uroot -p -Dmysql -e"SELECT * FROM information_schema.tables;"

give you?

diwljina · 07-27-2012, 01:01 PM

I did replaced it. And that command gives me information about other working tables. It's just problematic database that gives me empty set.

diwljina · 07-27-2012, 04:37 PM

Since all .frm files were gone, I managed to find some old backup. I restored old backup and that way restored tables definition. Then I copied new .MYD and .MYI over this restored, while retaining .frm's. Last step was repairing database with mysqlcheck -r and everything was working like before.

Kustom42, thanks for your help, anyway.

Kustom42 · 07-27-2012, 04:41 PM

Yep, that was the next step. Restoring the actual .MYI and .MYD files is sketchy but it can work. The fact that you were getting no info when doing the query against your info schema table confirms that the issue is with your .frm files which tell the MySQL database your table info. Just wanted to add this follow up for anyone else that runs into the issue. This is the last step you can attempt before you are up the creek so to speak.

diwljina · 07-27-2012, 05:03 PM

So, without frms it would be impossible to restore database?

Kustom42 · 07-30-2012, 11:36 AM

Without any one of the files(.frm, .MYI, .MYD) it would be impossible to restore. It is good practice to setup a cron job to make a mysqldump of your databases for backup purposes.

TenTenths · 07-30-2012, 11:39 AM

Quote:

Originally Posted by Kustom42

Without any one of the files(.frm, .MYI, .MYD) it would be impossible to restore. It is good practice to setup a cron job to make a mysqldump of your databases for backup purposes.

It's even better practise to replicate them to a slave server and take backups from the slave