TM backup: can I use two drives to back up data on two other drives?

For backing up the externals, in whatever way you want copies of one drive on another, I would do it manually. Time Machine is better suited for backing up you complete system, IE internal drive, in case of OS, software or hardware problems that cause your system to not boot properly and or to restore your system in case of a problem with any of those 3 things above.

It really isn't meant to be used to backup an external drive to another external drive. One reasons for this is the TM backup can basically only be restore using TM, although you can copy things out of it IF you haven't encrypted it.

You are asking a lot of TM and your Mac. As most all only have 2 USB ports and copying from one USB drive to another is un-godly Slow and even slower using TM.

Sounds like a Plan. Seems fine.

Just one thing, Redundance is the only key to NOT Losing all your data.

I personally have backup of all my important files on multiple computers and backups of all those computers on external drives.

Sorry I didn't get that far in your chart to see or read you were considering a Mirrored RAID system. But in the end that type of system IMHO, RAID, is better done with a NAS system where the RAID is done on multiple drives in the NAS and not between external drives connected directly to a system.

For it to be done on external drive it would be best to have 2 exact drives of the exact same size connect to the same ports, IE TB FW or USB, on the computer.

Again this, the NAS, adds another layer of Redundancy further protecting your data from total lose.

Instead of a RAID system connected to the computer directly all you need is a program to Mirror data from any Folder or Drive to another drive whether it is physically attached to the system or a NAS box that can do, or it doesn't have to do, RAID.

IMHO= In My Honest Opinion

NAS= Network Attached Storage

Thanks for the Great Day wishes.

Best of Luck to you and Best Wishes.

somanna wrote:

. . .

1] Use the 3 TB Seagate EHD wholly for TM based backing up data on my Mac's internal HD [500GB] and the data on my Thunderbolt in which I would be editing videos.

You can do that, of course, but it may not be your best bet. There's a bit of a trade-off:

• If you want hourly backups of all the changes to the videos, it will make those. If you do that, you'll probably want to use a fast drive for those backups. FireWire will be much faster than USB 2, of course.

• The downside is, all those changes will take up a lot of space on the backup drive, reducing the number of backups TM can keep. TM will "thin" them after 24 hours, keeping only the first of the day, but that will still probably take up a lot of space pretty quickly. That may be ok, but keep it in mind.

2] Make 2 partitions of 'e': a 500 GB partition onto which I intend to copy the present data on my Mac's internal HD, and a 1.5 TB partition in which I can store personal data.

I'm a bit confused -- if TM is going to back up your internal HD, do you mean the 500 GB partition will be a different backup of your internal, such as with CarbonCopyCloner or SuperDuper? If so, yes, keeping "secondary" backups in case there's a problem with the main backups is always prudent.

Then the question is, how are you going to back up the other 1.5 TB partition? (I may have missed that.)

As I think you know, Time Machine can have only one set of volumes to be backed-up, and whatever it backs up must go to a single volume.

What I would suggest is, keep it as simple as possible:

• Have Time Machine back up your internal HD. You might want to have it also back up an external if you want hourly backups of it, if you can do so without taking up too much space, as above.

• Then back up the other drives/partitions with CCC or SD, to separate drives/partitions. Unlike Time Machine, those apps can have separate backups (CCC calls them "tasks"), so you can have task #1 back up one drive, task #2 backup another, etc. It's probably best for them not to run at the same time, but they can. Each task can have a separate schedule, too -- you might want one to run daily, another to run weekly, etc. If you want to back up the video drive more than once a day, you can set up separate tasks to run daily at different times, but do the same thing. Just don't let them overlap.

• You may want "secondary" backups of some or all of your volumes. Those can also be done with CCC or SD. Consider doing at least some of them to one or more portable external HDs, so you can take them to a secure off-site location.

Also, as Shootist says, RAID is a very handy thing for operations that need to be online all the time, but not so much for backups. That's usually true whether they're on a NAS or a directly-connected enclosure.

I'd advise against much, if any, manual copying as a regular backup procedure. If you're anything like me, it's much too easy to forget (or think you did it when you didn't).

As we discussed earlier, this is not a "one-size-fits-all" sort of thing, especially with your complex setup and requirements. Pick whatever seems optimum, then adjust as you see how it works.

somanna wrote:

. . .

If you can analyse this plan and give your insight upon this matter, I will be immensely happy.

See below.

Further, if this proposed use of the 3 TB Seagate is okay with you, I need to know how to remove the Thunderbolt from doing it's temporary role of TM backup and how to coronate the 3TB Seagate as its successor.

• To start using another drive for Time Machine backups, be sure it has the GUID partition map scheme, and the Mac OS Extended (journaled) format, and is empty. Then all you have to do is click Select Disk on the TM Preferences window and choose it. That will turn Time Machine ON, and it will start a backup in 120 seconds, or immediately if you quit System Preferences.

• To start using the Thunderbolt drive for something else, just erase or repartition it via Disk Utility.

FYI, I would be switching off TM from functioning whenever I am editing video; I would be switching it on only after a full editing session.

You can do that, but I wouldn't recommend it. First, if you're like me, it's too easy to forget. Second, if your editing sessions are much longer than an hour, you'll be losing the hourly backups of your OSX drive -- even if you aren't doing much else while editing, you may have e-mails coming in, and/or if you're using an Internet browser or have anything running in the background, you won't have the hourly backups of those changes. And it's too easy to forget to turn it back on.

What you might want to do instead is, partition the 3 TB drive (d). Use one partition (perhaps 3 times the size of your internal HD) and use it for Time Machine backups of your internal HD only. Leave Time Machine ON. Since there won't be many changes to your OSX drive during your editing sessions, the hourly backups won't be large or take much time. As an example, I rarely notice mine unless I happen to see the icon spinning; they're almost always under a minute, anyway.

Use a different app, such as CarbonCopyCloner or SuperDuper, to back up the Thunderbolt drive to the other partition on (d). If you use CCC, you can set up a predefined "task" to do that, and run it by just clicking on it. I don't use SuperDuper, but understand it's also easy to set up such a task.

That way, the above backups are all on drive (d), but on two separate partitions.

Another question on my mind is this: do I need to partition the drive 'e' at all?

For best results, yes. I'm not sure how you're going to keep the "secondary" copy of your internal HD up to date, but I'd recommend CCC or SD for that as well. That partition can be the same size as your internal HD, and it will be best to keep it separate from the other data on that drive.

But again, only you can tell what's going to be best for your workflow and circumstances. Start with something, see how it goes, and adjust if it seems prudent.

Also consider some off-site backups, to protect you against fire, flood, theft, direct lightning strike on your power lines, etc.

EDIT: I should add, there are other backup apps besides Time Machine, CarbonCopyCloner, and Super Duper. But those are the most popular and easiest to use. If you're interested, a few others are listed in the green box in Time Machine - Frequently Asked Question #27.

Message was edited by: Pondini