5 ms·

> A few minutes planned downtime now in much better than hours of unplanned downtime at some indeterminate future time. This reminds me of something that OpenS

> A few minutes planned downtime now in much better than hours of unplanned downtime at some indeterminate future time. This reminds me of something that OpenSolaris did that I really liked. When you updated packages, it would take a ZFS snapshot. It only took up space for the changed bits, and happened almost instantly. If things stopped working after the reboot, then you could select a GRUB menu option to boot into the old snapshot again and everything would work.

nodata 15y ago
So how does it work in practice? 1. You upgrade postgres, and the new on-disk format isn't compatible with the old one. 2. You upgrade mysql, and the new on-disk format IS compatible with the old one, but the new version has a bug that you keep hitting. You want to downgrade without losing all the transactions that you've accrued since the upgrade.
- jamespo 15y ago
  You use backups and do proper testing in a staging environment
  - nodata 15y ago
    Which kind of negates the benefits of this feature.
    - bensummers 15y ago
      ... for databases. But for other kernel level things, eg drivers, it's great.