Toby Dickenson wrote:
On Monday 02 June 2003 10:18, Peter Sabaini wrote:
in the upcoming 2.6 edition of the zope book i (hopefully) covered this (http://www.zope.org/Documentation/Books/ZopeBook/2_6Edition/MaintainingZop e.stx).
That /etc/cron.daily/zbackup.cron script is dangerous in several ways. Think of backup as a database operation - this script has no ACID.
please explain -- why would i need transactions and concurrency with a backup script?
rsync doesnt even give any performance advantage here. rsync is good if you are doing backups remotely over ssh, but for local backups (like this script) it cant beat "cp".
not that i have any numbers to back this up but i think that just copying the difference of two similar Data.fs's can be advantageous with large files -- of course this will really only make a difference if the backup is to a network mount or something like that.
I strongly recommend DirectoryStorage if you want to keep daily backups like this. It has a standard tool for creating local incremental backups as tar files, or synchronising a remote replica of the storage. These tools are ACID, and efficient. Unlike all the home-brew FileStorage schemes I have seen.
DirectoryStorage sounds great if you have the requirements, but for simpler sites (or sites which host their data in an RDBMS anyway) FileStorage is just ok. - peter.