In my case, the NAS is a Synology server. I don't know how to determine authoritatively where the fault lies, but I trust it more than I trust Time Machine. (Although I am using btrfs on that volume so maybe it's a wash.) I'm sure I've disconnected my Mac from my Thunderbolt dock (and thus the active NIC) and/or put my Mac to sleep mid-backup many times, though. This is something that I would like it to be robust to but may be "the problem".
Interesting idea to reset the state. I think I can take snapshots with Synology. I'm unsure how to manage the details though:
* I let Time Machine starts backups automatically whenever it pleases. Does it have a hook to run a command to take a snapshot?
* Does it do the verification every time, or (say) 1 in 10? If the latter, going back to the most recent snapshot isn't enough. And if you do say 3 backups then get rid of #3, can it take incremental #4 on top of #2, or will it complain that the #3 state it expects is absent?
I really should just set up a different backup system. I do at least have Google Drive sync on most everything important. It's not a "real" backup as another poster pointed out, but it's better than nothing.
> * Does it do the verification every time, or 1 in 10? If the latter, going back to the most recent snapshot isn't enough. And if you do say 3 backups then get rid of #3, can it take incremental #4 on top of #2, or will it complain that the #3 state it expects is absent?
I don't believe it does the verification every time. I can't remember what the criteria is (I assumed it was similar to fsck on boot for Linux). You can run verify manually (Option-click the menu bar) and I'm sure there's a command line--so maybe you want to schedule your backups explicitly and verify every time? I've always had a corrupt backup when I've manually mounted the disk image and mucked around, so it's easy to restore within two days. I thought I might have issues with the client/server state mismatch, but haven't in practice (I've only needed to two this a few times). I haven't kept close track to see if I lose any in between backups--but I restore so rarely I wouldn't miss them.
> I really should just set up a different backup system. I do at least have Google Drive sync on most everything important. It's not a "real" backup as another poster pointed out, but it's better than nothing.
I've kept to the 3-2-1 backup rule and kept bootable backups local and non-bootable ones remote.
Same here. I'm also using BTRFS (I've not had a problem and my understanding is Synology doesn't use the flakier features of BTRFS). I can't remember if I'm using AFP or SMB (SMB I think is the only one Apple supports), but my backup is encrypted and I have a specific user. I'm not sure BTRFS matters all that much because the backup is a disk image. When I've had them get corrupted I've run disk utility on the disk image to fix things--there's a lot of layers to unwind.
I hear stories of people having issues with similar setups, but I haven't (I know that's a sucky answer to hear). Years and years ago I felt like I would get a corrupt backup when I closed my lid during a network backup (I believe this was pre-APFS), but I haven't noticed an issue in years. I have it auto-backup and it usually does it at night when the lid is closed and it's charging.
In Snapshot Replication I have a daily snapshot created at midnight with a 2 snapshot retention. I tend not to run out of space, so I'm fine with any deletes taking a few days to roll off. "Recover" under "Recovery" can restore old snapshots easily. I do this for most all of my Shared Folders.
Interesting idea to reset the state. I think I can take snapshots with Synology. I'm unsure how to manage the details though:
* I let Time Machine starts backups automatically whenever it pleases. Does it have a hook to run a command to take a snapshot?
* Does it do the verification every time, or (say) 1 in 10? If the latter, going back to the most recent snapshot isn't enough. And if you do say 3 backups then get rid of #3, can it take incremental #4 on top of #2, or will it complain that the #3 state it expects is absent?
I really should just set up a different backup system. I do at least have Google Drive sync on most everything important. It's not a "real" backup as another poster pointed out, but it's better than nothing.