On 3/4/20 3:49 PM, Lars Marowsky-Bree wrote:
On 2020-03-04T15:44:34, Wido den Hollander <wido@42on.com> wrote:
I understand what you are trying to do, but it's a trade-off. Endless snapshots are also a danger because bit-rot can sneak in somewhere which you might not notice.
A fresh export (full copy) every X period protects you against this.
Hrm. We have checksums on the actual OSD data, so it ought to be possible to add these to the export/import/diff bits so it can be verified faster.
(Well, barring bugs.)
I mainly meant bugs, I should have clarified that better. Do you trust the technology you want to backup to create the proper backup for you? With that I mean, what if librbd or librados contains a bug which corrupts all your backups? You think the backups all went fine because the snapshots seem consistent on both ends, but you are not sure until you actually test a restore. Those are the things I take into consideration when using such technologies. Wido