On Wednesday 28 May 2014 13:07:49 Alan McKinnon wrote: > 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
Haha :) I know the feeling. I'd love to know the final solution they came up with. > 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. Using snapshots, the downtime is the same couple of minutes each night. The problem is that during the backup, the performance of the server is impacted. For a full backup, that means weeks... -- Joost
