Archives For restore

One-liners are always fun. Linux has pipes, streams and redirects which you can combine to do many things in just one line. Today I had to restore a MySQL backup that was gzipped. Instead of typing:

gunzip db-backup.sql.gz
mysql -p -h dbname < db-backup.sql

You can type this instead:

gunzip < db-backup.sql.gz | mysql -p -h dbname

The .sql.gz file is input to gunzip, the resulting (unzipped) data is piped to mysql and is used as input there.

It will preserve the .gz file and saves diskspace as the unzipped file is not saved to disk. When using big databases, this is also a time saver. When using two commands you have to wait for the file to unzip, before starting the actual import. No intervention is needed when using the one-liner.

Just a quick instruction on howto restore an OpenLDAP server using a ‘ldif’-backup-file:

1. Setup the server

2. Configure the ‘slapd’ package, be sure to use the right database name. It’s a bit confusing: you enter it as, but this will be used to create an empty database. Make sure it matches your backup ldif structure.

3. Make sure OpenLDAP is stopped

4. Read the backupdata into the OpenLDAP database using slapadd program

slapadd -c -l backup.ldif

The -c continues on errors, which might be necessary for example because the ‘root’ is already created. You can also run without it, and fix any errors by hand in the backup.ldif file. -l specifies the file to read from.

5. Fix permissions, make sure ‘openldap’ is both user/group owner

6. Start OpenLDAP and the server should be up & running again!