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Why I Don’t Rely on Time Machine

joeontech.net

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Re: Why I Don’t Rely on Time Machine

#21

Post by e40 »

cdumler wrote: post #3

This is a good time to remind people about proper backups: the 3-2-1 rule. 3 backups. 2 backups (or more) should be on different mediums. 1 (at least) should be offsite (ie. home copy at work or in the cloud) You need three backups. If we assume that every copy has a chance small but real chance of failure, the chance of all failing at once becomes exponentially less with each copy. You need at least two different sy…

Yep. For Macs, that means something like TM + Superduper (or CCC). I do a weekly backup with SD which I copy to another machine on my network and backup offsite.

Re: Why I Don’t Rely on Time Machine

#22

Post by h4waii »

raamdev wrote: post #18

I've never used Time Machine specifically because I heard early reports of it not saving someone who suffered a total disk failure. I haven't bothered trying it since then. (First impressions are powerful things.) I've used Carbon Copy Cloner (a glorified rsync + a great UI) for 5+ years and I've survived no less than two total disk failures. The best part is that CCC makes my full-disk backups bootable, so I can lit…

You replace an entire laptop when you have a tiny drive failure? A 256GB SSD is ~$200 depending on form factor.

Re: Why I Don’t Rely on Time Machine

#23

Post by rcthompson »

ioquatix wrote: post #14
wiredfool wrote: post #10

I'm convinced that time machine over a network is a bad idea. Seems convenient, but if there's network flakiness, TM will decide that the backup is bad and force you to create a new one. And the first step in that process is to delete the existing backup. I had that happen once, when the drive I was backing up was in the process of failing. It got about 5gb into the new backup before it was totally dead. Even a somew…

Deleting the old backup is no longer the first step AFAIK. Yes, I have seen that behaviour in the past. Now, it gets renamed and then deleted once the next backup is completed successfully.

Still, it sucks that the solution involves losing your entire backup history.

Re: Why I Don’t Rely on Time Machine

#24

Post by coldtea »

>Huh. The Time Machine preference pane suggested that I try again later, and I did, with the same result. Since there was an error creating a folder, I guessed that the disk might have some errors, so I ran Disk Utility. Sure enough, there were errors, but Disk Utility couldn’t fix them. Neither could DiskWarrior. Or TechTool Pro. So I was left with no choice but to reformat the disk and start over from scratch. I still don’t know what caused the problem, but neither Time Machine nor any disk utility I tried could fix it—and the hardware itself was, as far as I could tell, just fine.

The last sentence makes absolutely no sense. He said Disk Utility found errors, but couldn't fix it, and neither could DiskWarrior and TechTool Pro. So clearly the hardware itself was NOT "just fine".

>When my backups become suddenly inaccessible for unknown reasons and I’m offered no solution but starting over, that sort of diminishes my faith in the software.

In light of that, what should Time Machine have done? Magically fixed a disk 3 specialized disks couldn't fix and continue?

What would ANY other backup software do?

Re: Why I Don’t Rely on Time Machine

#25

Post by bboreham »

hga wrote: post #20
cdumler wrote: post #3

This is a good time to remind people about proper backups: the 3-2-1 rule. 3 backups. 2 backups (or more) should be on different mediums. 1 (at least) should be offsite (ie. home copy at work or in the cloud) You need three backups. If we assume that every copy has a chance small but real chance of failure, the chance of all failing at once becomes exponentially less with each copy. You need at least two different sy…

I like to say that if you have 1 copy, you have none. If 2, 1, if 3, you have 2 copies, the absolute minimum. And try to decrease single points of failure, e.g. I use rsync for rsync.net and BackupPC to local disk, and tar to LTO tape after giving up on the opaque and baroque Bacula. You need one offsite to prevent your house burns down and takes your machines and local backups. I'm a long term fan of tape, from the…

> Current LTO-4 and LTO-5 tapes [...] go for $22-23, uncompressed capacities are 800 and 1.5 GB respectively.

I think you meant 1.5TB.

However, why not just use hard disk drives at just over twice that price? You'd get quite a lot of them for the cost of the tape drive.

Re: Why I Don’t Rely on Time Machine

#26

Post by keithpeter »

facepalm wrote: post #7

I've had the same experience, TM backups were suddenly broken several times.

Did the backup drive perhaps become unplugged or fail to unmount cleanly?

I've managed to do that to an external hard drive under Linux and had the drive labelled as read-only subsequently.

Just wondering aloud...

Re: Why I Don’t Rely on Time Machine

#28

Post by rangibaby »

h4waii wrote: post #22
raamdev wrote: post #18

I've never used Time Machine specifically because I heard early reports of it not saving someone who suffered a total disk failure. I haven't bothered trying it since then. (First impressions are powerful things.) I've used Carbon Copy Cloner (a glorified rsync + a great UI) for 5+ years and I've survived no less than two total disk failures. The best part is that CCC makes my full-disk backups bootable, so I can lit…

You replace an entire laptop when you have a tiny drive failure? A 256GB SSD is ~$200 depending on form factor.

I'm a Mac user and buy their extended warranty, which covers HW failures for 3 years. There are really no replaceable parts in their new laptops (soldered SSD and RAM!), which is a shame but an OK (not great) compromise considering their weight and other advantages.

Re: Why I Don’t Rely on Time Machine

#29

Post by joesmo »

I experience failures like this with Time Machine every couple of months. The only thing to do is wipe the previous backup and start anew. This happens on all my Macs so it's not device specific nor is it related to the underlying backup medium which is working perfectly. If you absolutely cannot take even the smallest chance of losing your data, TM is not a good choice. If you need something that runs for years on end reliably, TM is a terrible choice. It won't do that. If you can deal with the regular FUBAR'd backup and redoing it from scratch (so you have about a 24 hour period with either no backups or two separate backups) it's not a bad system. Sure is better than whatever Windows 7 offers which will never remove old data and will inevitably lead to full disks.

Re: Why I Don’t Rely on Time Machine

#30

Post by hga »

bboreham wrote: post #25
hga wrote: post #20

Earlier quoted context omitted.

I like to say that if you have 1 copy, you have none. If 2, 1, if 3, you have 2 copies, the absolute minimum. And try to decrease single points of failure, e.g. I use rsync for rsync.net and BackupPC to local disk, and tar to LTO tape after giving up on the opaque and baroque Bacula. You need one offsite to prevent your house burns down and takes your machines and local backups. I'm a long term fan of tape, from the…

> Current LTO-4 and LTO-5 tapes [...] go for $22-23, uncompressed capacities are 800 and 1.5 GB respectively. I think you meant 1.5TB. However, why not just use hard disk drives at just over twice that price? You'd get quite a lot of them for the cost of the tape drive.

Because tapes are much less fragile than hard disks, and I can stash a bunch of tapes in my safe deposit box and other places. As well as have many copies of my data as I keep monthly full backups for at least a year. And, hmmm, my tapes as I use them are more reliable than my Seagate enterprise disks, and that's with the latter not moving around (i.e. in all my post-mid-2011 tornado hardware, I've had two disk failures and no tape failures).

For the level of data security I want, and the tiny AT&T DSL straw I'm currently forced to use, even with things like Amazon Snowball and ever lower prices on "nearline" cloud storage, if a tape drive lasts long enough, the numbers work better for tape. And compared to the usual enterprise, I don't beat up on tape drives, they're over-engineered for my duty cycle. I also have a desire to be able to make due without monthly charges, which a cloud solution doesn't allow.

And, yeah, TB not GB. The DAT tapes I used previously were in the GB range as I vaguely recall.

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