[Macworld]

Post your comments for How to create redundant Time Machine backups here

[TheBum]

Nice! I don't know how many times I've had a Time Machine backup from my MacBook Pro to my Mac mini go bad. There is a method for repairing a remote backup if the filesystem is accessible and has errors, but the last time one went bad, the sparse image wouldn't mount at all. I had to start over.

Do the files from all the alternate backups get synced to each other? For example, if one of the alternating backups go bad, can a new one be "seeded" with the entire backup history of the remaining good backup?

This post has been edited by TheBum: 28 January 2013 - 08:30 AM

[Chris Breen]

TheBum, on 28 January 2013 - 08:28 AM, said:

Nice! I don't know how many times I've had a Time Machine backup from my MacBook Pro to my Mac mini go bad. There is a method for repairing a remote backup if the filesystem is accessible and has errors, but the last time one went bad, the sparse image wouldn't mount at all. I had to start over.

Do the files from all the alternate backups get synced to each other? For example, if one of the alternating backups go bad, can a new one be "seeded" with the entire backup history of the remaining good backup?

The files don't get synced to each other. Basically, when one comes on line (Time Machine chooses it) it looks for any changes since the last time it was backed up and incorporates those changes, much as a single Time Machine backup would.

If one goes bad, you'll have to manually make a copy of the good one. Apple explains how.

[markbarron]

Wish List.

Hourly backups based on the time the computer was on.
So on Monday you would see Friday's hourly backups.

Or better yet.. select how many hourly backups to store all based on hour of operation of the computer.

[ganbustein]

I back up to multiple drives, but I do it by plugging the one I want to back up to into a VoyagerQ dock. This thoroughly confuses Time Machine, apparently because they all wind up with the same Unix device name (/dev/disk2s3, for example). Only one of them is actually mounted at any one time, and they have different names and different GUIDs, but TM still gets them mixed up. (I get messages about this being a foreign backup that someone may be trying to trick me into backing up to, and if I tell it to proceed anyway it tries to back up everything all over again.)

To switch backup volumes, I have to manually tell it to stop backing up to one and then tell it to start backing up to the other. Even then, TM sometimes forgets that it's supposed to be doing hourly backups, and I have to turn automatic backups off and on again to get it going again. All of that makes maintaining multiple backups harder on MtLion than it was on Snow Leopard, at least with my setup.

What would be nice would be if I could tell it about my regular backup volume and both of my offsite volumes, and have it automatically use whichever of the three is in the VoyagerQ dock at the moment, but sadly it doesn't work. I was really excited when I first saw this new feature of MtLion, but it's not quite ready yet.

[twocybers]

When I added a second external HDD for TM backups, I found one of the External drives shown an icon (either on Desktop or in TM) as an external drive i.e. orange and the other was expected Green/Teal TM icon. If you work hard you can change the icon colors, but always one or each. Very unexpected on my part.

Gordon

[pwwwayne]

I have 2 Time Capsules, using only 1.

When I try this process, all I get is "Set-up" the 2nd TC, which then opens Airport Utility, does not show me a way to setup the 2nd TC

and therefore I don't get the TM option of "Use Both"

Huh, how to Setup the 2nd TC; it is shown in Airport Utility but nothing about setup.

[brianfrick]

Quote

I have 2 Time Capsules, using only 1. When I try this process, all I get is "Set-up" the 2nd TC, which then opens Airport Utility, does not show me a way to setup the 2nd TC and therefore I don't get the TM option of "Use Both" Huh, how to Setup the 2nd TC; it is shown in Airport Utility but nothing about setup.

Right, because your Time Capsules exist as two different networks, and therefore two different network drives. You would need to switch networks to backup to either Time Capsule, and most likely, you'd have to do it manually.

[DocNo]

Quote

I back up to multiple drives, but I do it by plugging the one I want to back up to into a VoyagerQ dock. This thoroughly confuses Time Machine, apparently because they all wind up with the same Unix device name (/dev/disk2s3, for example). Only one of them is actually mounted at any one time

I suspect if you take one of your secondary backups and recreate it while you have your main time machine backup also mounted using the add a disk feature as outlined in the article you won't have that issue any more. Should be a one time thing.

I agree you shouldn't have to, but I'll bet that solves it.

[bjmac]

Thanks for this helpful article. What I'm wondering, however, is if there is a way to have a different exclusion list for each of the TM backups.

Consider this senario: The user has 40 gigs of photos & music that they would like their home TM to backup. That same user also backs up to their office TM (In our case a dedicated Mac Mini Server) - where they do not want those 40 gigs of photos & music stored (for obvious reasons). Is there a way to have each TM backup have its own exclusion list?

If not with TM, with some other automatic backup program?

[DBSteve]

Quote

Thanks for this helpful article. What I'm wondering, however, is if there is a way to have a different exclusion list for each of the TM backups. Consider this senario: The user has 40 gigs of photos & music that they would like their home TM to backup. That same user also backs up to their office TM (In our case a dedicated Mac Mini Server) - where they do not want those 40 gigs of photos & music stored (for obvious reasons). Is there a way to have each TM backup have its own exclusion list? If not with TM, with some other automatic backup program?

[DBSteve]

Based on the questions and scenarios I see people posting here, I think that many are forgetting that Time Machine is meant to be an elegant but simple way for the average Mac user to backup their data. Very few users will need to do any more than have one or two backup volumes. If you need a more complicated scheme get a dedicated backup utility such as Retrospect. You could let Time machine take care of your hourly backups for immediate security and another utility to back up on different schedules to different volumes with different backup parameters. It's not fair to expect Apple to provide a free utility to do some of these complicated backup scenarios.

[MartinJo]

I use 2 separate drives for Time Machine. One is attached to the Mac, and the other is off site. Every few days I swap them over. Both have the name name, so TM doesn't get confused.

[eedrac]

I have two backups set up in TM. I keep one off-site and every week or so, I switch the two. I don't keep the drives plugged in to my laptop – I plug in the TM drive when I want to back up. However, when I do that, it always tells me that it can't find the missing TM backup. In Lion, I was able to set up two drives and just switch them in TM preferences when I physically swapped the drives. Is there a way I can do that or do I just have to dismiss the warning every time TM tells me that the other drive is missing? Thanks!