On 26 Jan, luke wrote: > I was talking about our backup strategy to my wife tonight (2 sets of > full backups, nightly incremental backups onto CDRW: again, 2 CDs that > we cycle between), and we started discussing what seems to be a huge > hole in this common strategy.
Summary of discussion: Terry Collins suggested just burning them to CDR. The cost is $100, plus all the handling and storage of 365 CDs through the year. Destroying the unwanted bult yearly would be a task I wouldn't volunteer for. So that solution doesn't appeal. I can imagine the pain of an error in the labelling system and the restore drama that would ensue! I guess I wasn't clear that the full backups take about 10 CDRWs these days. The pain of the full backups is not the cost, it's the hours it takes to do. So any strategy that requires regular full backups is out. (Unless I change over to using DVDRW and put off the pain for a few more years or new technology.) The incrementals run nightly (as Terry suggested), but a full backup takes hours and manual feeding of the burner. Grant seemed to miss the point that if the file is created after the full backup, and later damaged, it's lost after N days, where N is your incremental cycle period. DaZZa suggested appending incrementals I think. I guess a multi-session CD might equate to that, so you could fit 100MB of incremental changes before needing a full backup. But it only takes a few 50MB mail folders to exceed that. So this would suggest using more expensive technology than CD burners (and would force more frequent full backups, ugh. Instead, I'd slip in an extra level of backup.) It also only gives you a slightly longer grace period. Then Peter Hardy wrote that http://www.cdfreaks.com/news/7751 reckoned many CDRs go bad within 2 years. I don't know anyone personally who's had any problem. Sounds bizarre to me. Hmm, maybe my proposed solution of slipping in a monthly isn't so dumb. Or maybe going to 3 levels of backup would be more rigorous. At present we use 2 levels simply because that's convenient for the media sizes. Ah, that's it. I should go to 6 CDRWs for level 2 incrementals, and label them Mon - Sat to make it clear which one should be used when, to reduce chance of human error. Then have 4 CDs used for level 1 incrementals, labelled Week 1 through Week 4. Yes, I think that should work nicely. luke -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
