On 28/05/2014 11:58, Joost Roeleveld wrote: > On Tuesday 27 May 2014 23:35:26 Alan McKinnon wrote: >> On 27/05/2014 17:12, J. Roeleveld wrote: >>> I have a yearly (full), monthly, weekly and daily. Each incremental is >>> against the most recent one of itself or longer period. >>> That means having to keep multiple snapshots active, which I prefer to >>> avoid. >>> >>> But, it is a good idea for backing up desktops and laptops. >> >> I'm curious why you have yearly snapshots. I've yet to find any sane >> production system where a yearly backup had any worth at all. Even >> monthly is pushing it... >> >> Or do you do it to have a decent start point for incrementals? > > It's to have a decent start point for incrementals. > Below are the 2 biggest shares on the NAS: > > /dev/xvda17 7.1T 5.9T 1.2T 84% /data/unsorted > /dev/xvda16 3.0T 2.4T 517G 83% /data/software > > It is impossible to do a full backup on a daily or even weekly basis. > > Previously, I had 1 full backup and then a daily incremental. This appears > like a good idea, untill you need to restore the filesystem from backups when > the crash occured 2 years later. > That is 1 full backup and over 700 incrementals.... > > Currently, I do the following: > Every year, a full backup > Then, every month, I have an incremental based on either the yearly or > previous monthly. > Ditto for the weekly (but then based on monthly or weekly) > And again for the daily.
OK, that makes sense. It reminds me of an issue my wife had with the data warehouse when she worked at the bank. In a nutshell, they needed backups but backups were impossible to achieve because physics says so. They needed to get data off the disk 4 times faster than data comes off a disk - SCSI limits being rather hard limits :-) That opinion didn't go down well when I offered it The solution was to do it much like your plan above. With the benefit that the infrequent full backups would be done on a fixed schedule in a change window with X hours downtime that was known well in advance. -- Alan McKinnon alan.mckin...@gmail.com
