Why System Snapshots?

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kmph
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Why System Snapshots?

Post by kmph » Tue Oct 02, 2018 1:58 pm

Gave Lm19 a try... and it wants me very badly to set up system snapshots.

OK I get the reasoning... if an update breaks something etc... But I'm still in doubts about this feature..

1. You want me to enable daily snapshots and boot snapshots. Wow thats a lot of snapshots! With that many snapshots though, why not simply... make Mint a rolling distro? Stability is the reasoning behind allowing multiyear delays wrt shipping new versions of software to Mint. But that may snapshots...+ the recommendation to update everything seems to... as if the devs' current policy was that they're moving from the hard requirements of stability (that were not always being met in past tbh) and instead they say, "if anything breaks, just restore a snapshot". But with such a reasoning they could make Mint a rolling release as well. multiyear delays + lots of snapshot = something seems overkillish, something seems too much. Either strive to provide as much stability as possible to make snapshots unnecessary... or ship new software...?

2. Were to store the snapshots? Connected problem: Only snapshot system files or treat snapshots also as a backup facility to backup personal data?

2a) If only snapshot system files, then we can very well store snapshots on HDD... BUT then we have to have 2 backup facilities, one for system and one for personal data, which is too much again! Also: Windows has this annoying feature of randomly deciding it needs to use 100% of my HDD. The results are performance degradation and I wonder when will Windows finally kill my HDD? Is this coming to Mint as well?
2b) If personal files as well... Then we shouldn't store snapshots on HDD because one big reason to store backups of personal data is to protect them from dreaded HDD failures! So we should store them externally. Then again! - externally means where? My computer is a laptop. I refuse to have an USB disk connected to it all the time, thats just impractical. But then if I connect the USB disk manually then I wont set scheduled snapshots the system wants me to set! Also: I used to be using LuckyBackup to backup personal data onto external HDD. I dualboot windows; to make things easier (backup from one place) I was using lucky backup to backup personal files stored on windows as well. Can snapshots do this?

gm10
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Re: Why System Snapshots?

Post by gm10 » Tue Oct 02, 2018 2:12 pm

1. Up to you whether you need it. I have it enabled but I only run weekly snapshots. I've yet to need to restore one. Boot time snapshots sound like a terrible idea to me.

1b. Your rolling release argument is completely missing the point. LTS releases still receive bug fixes, that's the whole point ("long term support"). Nobody can help you if you don't want to install bug fixes, so I won't comment on that further.

2. Snapshots != backups. If you were to include personal data (your home folder is excluded by default) then restoring a snapshot to restore a previous system state would also restore that same previous state to your personal data. In almost all cases that's not what you'd want.

kmph
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Re: Why System Snapshots?

Post by kmph » Tue Oct 02, 2018 2:50 pm

gm10 wrote:
Tue Oct 02, 2018 2:12 pm
Your rolling release argument is completely missing the point.
How so?
gm10 wrote:
Tue Oct 02, 2018 2:12 pm
Nobody can help you if you don't want to install bug fixes, so I won't comment on that further.
I did not say I didn't want to install bugfixes!!

I only said that the (valid!) argument against rolling is that with rolling the updates are likely to introduce regressions and break stuff. But THAT many snapshots provides such shielding against this...that both snapshots AND freezing software versions to avoid regressions seems quite overkillish.
gm10 wrote:
Tue Oct 02, 2018 2:12 pm
2. Snapshots != backups. If you were to include personal data (your home folder is excluded by default) then restoring a snapshot to restore a previous system state would also restore that same previous state to your personal data. In almost all cases that's not what you'd want.
Solution: While restoring a snapshot, give an option whether i want to (a) restore system files (b) home dir (c) both. If in a very similar way i can be protected against regressions AND HDD failures, then why not?

gm10
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Re: Why System Snapshots?

Post by gm10 » Tue Oct 02, 2018 3:05 pm

kmph wrote:
Tue Oct 02, 2018 2:50 pm
I only said that the (valid!) argument against rolling is that with rolling the updates are likely to introduce regressions and break stuff. But THAT many snapshots provides such shielding against this...that both snapshots AND freezing software versions to avoid regressions seems quite overkillish.
Still completely besides the point. Regressions are not specific to feature updates. And why are we discussing regressions again?
gm10 wrote:
Tue Oct 02, 2018 2:12 pm
Solution: While restoring a snapshot, give an option whether i want to (a) restore system files (b) home dir (c) both. If in a very similar way i can be protected against regressions AND HDD failures, then why not?
You asked me a question, I gave you the answer. I'm not the author of that software so arguing what if's with me won't get you anywhere, suggest the feature to the author and see what he says. But as you nicely laid out yourself in your OP, you'd store user data in a different place than a system snapshot, so you already made the case against your own suggestion.

Hoser Rob
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Re: Why System Snapshots?

Post by Hoser Rob » Wed Oct 03, 2018 8:19 am

kmph wrote:
Tue Oct 02, 2018 2:50 pm
gm10 wrote:
Tue Oct 02, 2018 2:12 pm
Your rolling release argument is completely missing the point.
How so? ...
Because you need to learn ore about how rolling releases and Linux works. You want the new versions of software of rolling releases and LTS stability and you can't have both. Snaps etc have potential but aren't the answer.

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ud6
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Re: Why System Snapshots?

Post by ud6 » Wed Nov 14, 2018 4:50 pm

kmph wrote:
Tue Oct 02, 2018 1:58 pm
..something seems overkillish, something seems too much. Either strive to provide as much stability as possible to make snapshots unnecessary... or ship new software...?
Even if we use a 'stable' release, the system can crash. However, I agree that snapshots doesn't seem to be the answer. I and many others have had problems with timeshift (old snapshots not being removed and system thus filling disk and, ironically, crashing computer).

Snapshots best done on removable media (any problems and you can format the disk). But personally I just back up home (on large f2fs formatted SD card, so it is fast amd easy). I try not to tweak Mint too much, so if system crashes I can reinstall if necessary, without major changes. Part of the reason I use Mint is stability.

rambo919
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Re: Why System Snapshots?

Post by rambo919 » Thu Nov 15, 2018 3:02 am

Snapshots are not so much backups as insurance against system corruption of whatever kind, something especially needed for noobs or less technical users. Followed less intelligent cli advice with just the wrong command removing important system folders? Changed the permissions or ownership recursively from the wrong directory? Testing a possibly conflicting meta package? Use a snapshot and everything is exactly the way it was before you either accidentally or stupidly screwed up your system.

In my case (in a VM but still) I installed a handful of DE's to see the actual differences in feel and RAM usage... saw what I needed to see and reverted with timeshift. And the whole process was painless and fast without having to even lift the hood nvm go under it. I know timeshift is still not faultless but it's still a good step in the right direction for many and WAY better than M$ system restore in many ways.

Weekly snapshots should be fine for most. What effort is it to make one just before doing something risky the way a system restore point gets made as general rule in windows?

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