Tag Archives: mysql

report-storage.sh

In the grand tradition of my publishing little building-block shell scripts of interest, here goes another one. This is a simple cron job that I run daily on a number of hosts to generate storage usage growth. (This is in addition to Cacti and Nagios which poll some of this data already but for different reasons and with different granularity).

The FILES variable should be populated with a whitespace separated list of files, directories, and block devices to track.

The DB_ABCD variables should be populated with appropriate credentials to talk to a mysql server.

The actual script looks something like this:

I am putting my data into a table called “storage_usage” in a database called “metrics”:

Obviously, this could be tweaked in any different number of ways, based on your needs. One tweak you might want to consider if you’re running it in a daily cron is to remove the echo so you don’t get an email report of every run. Also, if you might want to record more than one snapshot per file per host per day – in the which case you probably need to change the type of the timestamp column to a datetime. Or there might be cases where you want to change the replace to an insert or… whatever 😉

xtrabackup innodb_file_per_table gotcha

Several months ago, I’d switched to using Percona’s xtrabackup & innobackupex for all of my mysql backup needs. I had successfully used these backups to restore and replicate databases across several systems. It is good stuff.

Last week, I needed to set up new replication of an 80gb database. This should have been routine by now, but when I attempted to prepare the backup this time, it whined and complained and failed. I was kind of frazzled by the time I gave up on the issue and declared it a fluke of one sort or another.

Last night, I tried again from Sunday’s full backup, and it happened again:

I gave up after poking a few things.

This morning’s fresh look turned up this bug report.

That’s right. There’s a bug in innodb restoration that interprets location of /tmp (configurable in my.cnf) to be relative in stead of absolute.

So, if you have problems while trying to restore from an xtrabackup/ibbackup snapshot (or if you’re trying to recover innodb after a crash), just creating the offending tmp directory appears to work.