not understanding storage numbers

[iStorm]

Um, if my internal system disk goes south, I'm going to lose a lot more than an hours work, even if I'm backed up by Time Machine to an external disk. Unless I get a speedy repair person to dismantle the machine and replace the internal disk. That's why a bootable backup is the way to go. In that case, I'm back in action in a minute or less.

True, but that's not what their post meant. It means that any work you did in the last hour is lost. That document you were working on a half hour ago? Gone... That spreadsheet you were working on 2 hours ago? Should be in the backup...

 

[Doug Lass]

This is true. If I do a once-day bootable backup, work that I'd done in the day is lost in case of a system disk failure failure. That's why I like Time Machine. BUT. if I want to get back to work within minutes, using a slightly aged system, that's why I like bootable backup.

 

[clevins]

So, I don't use TM at all anymore. I do this instead:

1) Carbon Copy Cloner bootable backup on reconnect to an external SSD. I'm on a MacBook so in practice this means every weekday morning.
2) streaming (close to real time) backups to Backblaze.

If I lost my internal drive I, at worst, have a bootable backup that is missing work from Friday-Sunday (if it Fritzes right before I connect and backup Monday AM). All of those files will be on Backblaze. HOWEVER, the odds of this happening a incredibly low. My internal SSD would have to die and it would have to happen late Sunday night or very early Monday AM.

Next worst case would be losing the internal SSD at the end of a day, meaning I'd need to restore that day's work from Backblaze.

NOTE that the odds of your internal SSD failing are very very low. So you have to ask yourself how much effort you're willing to put in to deal with the occurrence of a rare event compounded by the occurrence of another rare event (the SSD dying at the end of a weekend or day vs some other time in the middle of the day)?

You do you, but my setup gives me redundancy that I'm happy with and effectively zero hassle. NOTE that Backblaze also does the local snapshot thing and then uploads. At some point it's just better to let the software deal with this stuff.

 

[clevins]

Um, if my internal system disk goes south, I'm going to lose a lot more than an hours work, even if I'm backed up by Time Machine to an external disk. Unless I get a speedy repair person to dismantle the machine and replace the internal disk. That's why a bootable backup is the way to go. In that case, I'm back in action in a minute or less.

No you're not. The work will be there. Sure you lose time dealing this this, but... :shrug. Unless you're on a time critical project, you probably shouldn't just boot off your backup and continue working anyway since you're then working without a backup. In that case, I'd get a backup machine and restore to that, then continue working.


And you are kind of obsessing. You're worrying about the local snapshots... why? If TM is backing up to an external drive and as part of that it's doing the local snap then copy thing... so what? Your primary purpose (a bootable backup) is being created, so why worry about how it's done unless those snapshots are impeding your ability to work, etc?

PS: I'm not using 'obsessing' pejoratively but I'm trying to get at why you care about the process TM uses if the results achieve your goals. Hence my questions about what you're really after.

 

[Doug Lass]

So, I don't use TM at all anymore. I do this instead:

1) Carbon Copy Cloner bootable backup on reconnect to an external SSD. I'm on a MacBook so in practice this means every weekday morning.
2) streaming (close to real time) backups to Backblaze.

If I lost my internal drive I, at worst, have a bootable backup that is missing work from Friday-Sunday (if it Fritzes right before I connect and backup Monday AM). All of those files will be on Backblaze. HOWEVER, the odds of this happening a incredibly low. My internal SSD would have to die and it would have to happen late Sunday night or very early Monday AM.

Next worst case would be losing the internal SSD at the end of a day, meaning I'd need to restore that day's work from Backblaze.

NOTE that the odds of your internal SSD failing are very very low. So you have to ask yourself how much effort you're willing to put in to deal with the occurrence of a rare event compounded by the occurrence of another rare event (the SSD dying at the end of a weekend or day vs some other time in the middle of the day)?

You do you, but my setup gives me redundancy that I'm happy with and effectively zero hassle. NOTE that Backblaze also does the local snapshot thing and then uploads. At some point it's just better to let the software deal with this stuff.

As I've written, I also do a daily bootable backup (SuperDuper) to a second external disk. Time Machine offers the extra advantage that I can recover stuff on an hourly basis. I don't need to pay for a cloud backup.