Thanks, I appreciate that. I understand and have been known to take UFS drives offline or at least go single user in order to backup in the past.
I guess what I am truly looking for is a use for PFS. They feel like a technology right on the cusp of something I could use to make a big improvement to my workflow, but I cannot figure out how! Sent with [ProtonMail](https://protonmail.com) Secure Email. ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ On August 8, 2018 11:08 AM, patric conant <[email protected]> wrote: > Bryan, > > Without snapshots filesystem operations are not atomic, when you Backup, > copy, sync, rsync, you are not getting a cohesive operation, but the various > states of individual files at the time they are accessed. So, no, you can't > back up UFS, with any sort of guaranteed consistency, yes each file can be > consistent, but for example, the logs for services, and the file states of > those services are out of sync, now when you restore you have logs that are > not for point of time that the files are for. Snapshotting is pretty much the > cornerstone of modern storage. Next checksumming, which I'm not aware of UFS > support in. Without checksumming the only source of validity of a file is the > file itself. There's no guarantee or even expectation of file consistency, in > traditional file systems, just that we trust the hardware because we have to. > RAID mitigates this, to the tune of reducing it 50-90%, but an 8TB live data > set simply is not exactly what was laid down on the storage medium, and > there's no expectation of such. That's some of the nitty gritty of the modern > storage layer, but as we all know and experience, systems run for years > without these problems enjoying any sort of remedy outside of best effort, > there's probably machines with massive data-sets, and decades of history, > whom have been subject to these problems, being restored from file-level > backups many times, and having the total of the writes be in the multiple > petabytes range, and the applications running on top seeming no worse for > wear. This speaks to the resiliency to some level of corruption of most > applications. > > On Tue, Aug 7, 2018 at 6:57 PM Bob Obrien <[email protected]> wrote: > >> Hello there, >> I am enjoying Dragon Fly BSD so far, nice and snappy, seems sensibly >> organized. >> >> I like the idea of HAMMER but for my relatively basic uses I am not seeing a >> great benefits. Most notably, PFS seem to be a huge part of the design and >> what makes it tick. OK, cool, I guess you can snapshot via PFS. But wait, >> now you can snapshot ANY directory? mount_null also seems core to a basic DF >> setup but that is not limited to hammer at all. Backups, copies, syncs, yes >> it seems a neat organizational tool but at the same time I copy, rsync, etc >> etc with all my UFS drives and it works great. Assuming small enough files >> and drives that limitations are not being reached, of course. >> >> Maybe if I was a more advanced sysadmin type I would have more specific >> demands or use cases that would take advantage? >> >> Or maybe I simply need someone to explain how these benefit me and I will >> see the light, and improve my workflows. Thanks! >> >> Sent with [ProtonMail](https://protonmail.com) Secure Email. > > -- > Patric Conant > Mirage Computing Lead Consultant > @[MirageComputing](https://twitter.com/MirageComputing)on twitter > https://m.facebook.com/MirageComputing/ > 316 409 2424
