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I was always under the impression that a snapshot should be an short-lived thing. E.g. you take a snapshot, make a backup or copy from that, then delete the sna
by throwawayboise 5y ago
I was always under the impression that a snapshot should be an short-lived thing. E.g. you take a snapshot, make a backup or copy from that, then delete the snapshot. Where I work, the VM admins will only allow one snapshot at any point in time without special request and justification, and they encourage deleting the snapshot within 72 hours.
- lillecarl 5y agoDepends on the solution, but in many systems snapshots are cheap, like zfs or btrfs. I can imagine ceph snapshots being quite cheap too. Edit: people use snapshots to compliment backups too, you can do snapshots hourly and back a snapshot up daily. (They don't act as backups, more like "oops" revert solutions, humans are more likely to fail than machines) If you're using VMware or Hyper-V the backups rely on a dirty "bitmap" of which blocks has been written since last backup so it only has to pull those from the system, this doesn't work with more snapshots for some reason. Enterprise backup solutions will just pull the entire machine and compare what's changed anyways, but you usually get a warning about it. So grumpy admins
- throwawayboise 5y agoYes it's VMware.
- CodesInChaos 5y agoYou're using a rather narrow/implementation specific definition of snapshot. I believe EBS snapshots are equivalent to you temp-snapshot, incremental/deduplicated backup/delete temp snapshot combination. Logically it's still a snapshot, because it contains all data of the volume at a specific point in time, but the cloud provider abstracts away the details of how it achieves durability.