Mouting ZFS snapshot from S3 about z3 HOT 1 OPEN

Interested in this issue, I experimented with creating a ZFS filesystem based on a block device provided by s3backer. This allows me to store snapshots on S3, while also allowing me to consolidate the snapshots that are stored in s3 and delete them in any order. s3backer supports removing blocks where TRIM has been done to free up space in s3 and supports thin-provisiong of space (you can create a 1TB block device, and used space from s3 perspective is space used in zfs).

I see a risk in terms of the consistency of the data saved on the disk, which results from the very essence of s3backer. I notice that there is a local cache to reduce read-after-write consistency problems, but the backup system has clearly separated read and write sequences:

• writing are made when a new snapshot is stored,
• readings are taken as the snapshot is received back (usually several hours or weeks after writing).

I can imagine introducing a limit on how often different operations can be performed to ensure data security. In many cases, the restore operation is latency tolerant (may start 5-10 minutes later), especially when balancing its effectiveness.

from z3.