Archive for 'Sysadm'

Smart MySQL backup

I’m currently sysadmin for a bunch of dedicated servers, mainly running LAMP stacks. One the main issues with running a dedicated server is backups (the other being security). Remote filesystem backup can be easily performed with ribs (or any other rsync-based backup tool). ribs only copies changed files and creates hard-link snapshots to make each backup appear as a full backup. The main problem with rsync&hard-link based backup is MySQL.

It’s not wise to directly backup MySQL files; MyIsam files can be backed-up individually but their restore is not always guaranteed. Shared InnoDb tablespaces are very large and are modified each time you look at them. Single-table InnoDb tablespaces (with innodb_fle_per_table in my.cnf) are cumbersome to restore. On top of all that, data can be in a non-consistent state, so the copied file is corrupted (and useless).


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Mandrake Corporate to Centos

Triplo salto mortale carpiato senza rete (o quasi) perfettamente riuscito.

Problema: aggiornare un sistema da Mandrake Corporate 3 a Centos 5 riducendo al minimo l’impatto sugli utenti.

Visto che non era disponibile un hardware uguale o superiore a quello in produzione, non è stato possibile semplicemente installare una nuova macchina e migrare poco alla volta i servizi (cosa fatta alcuni mesi fa per un diverso cliente e riuscita senza grossi problemi). È stato quindi necessario ricorrere a un trucco da mago Silvan.

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