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ldrhawke
06-28-2006, 11:40 AM
can you back up to a partioned hard drive and have more than one bootable startup drive on it?

dnanian
06-28-2006, 11:50 AM
Yes, as long as the partitioning scheme is native to the Mac. In general, you should partition using "APM", unless your use is exclusively Intel-Mac, in which case you can use GUID.

Brad
06-28-2006, 01:22 PM
Yes, as long as the partitioning scheme is native to the Mac. In general, you should partition using "APM", unless your use is exclusively Intel-Mac, in which case you can use GUID.
Hi Dave,

I have a question for you regarding this (and a bit more!)... Here's what I'd like to do: Use an external drive to backup both a G4 iBook (using firewire) and a Dell laptop (also using firewire, or USB 2).

My thinking is that "something like this" will work: I partition (using GUID--is this part of OS X's utils?--I'm an OS X newbie) to make say, 90 GB of my 250GB firewire/usb drive formatted with HSB+(?) or whatever the Mac's native format is, then make the other 160GB (I have a bigger drive on the Dell laptop) either FAT32, or preferably (I think) NTFS. Then I use SD! to backup to the 90 GB partition and whatever software (probably the Retrospect that came with the drive) on Windows to backup the Dell to the 160GB partition.

So far so good or am I already in fantasy land? Can I make the other partition NTFS or is it better to stick with FAT32? Then...

Can I set it up so that the weekly or monthly is a Read/Write Sparse image that goes to the 90 GB partition (which I would perform), then the usual user of the Mac G4 iBook (my girlfriend) can just press the 'backup button' on the drive to do her daily to the same 90 GB partition? Or do I need to create a 30 GB partition and a 60 GB (her iBook has a 30 GB drive) and can I set it up so the backup button goes to the 30 GB partition for her dailies and then I just store the weekly and/or monthly sparse image to the 60GB? Also, how large do the SmartUpdate's grow? She's pretty close to the max on her 30 GB drive already, so maybe I should just have one "periodic" every couple weeks or so, and just make two 45 GB partitions? (Because her dailies will be done using Smart Update and the button.)

Or can I not even do the multi-partitioning for two OSes like I want (OS X and Windows)?

And also--you must think I'm in la-la land at this point--we will be able to boot off the daily backup done by the button (that is, SmartUpdate-d)?

Sorry for such a long and detailed question, but I'm guessing that others may want to do a similar thing and might benefit from your answers...

Btw, I when I was in Fry's buying my firewire drive last night, the guy standing next to me said, "Oh yeah, that drive works great on the Mac, boots from the firewire and everything, and by the way, have you ever heard of Super Duper!? That's the *best* software!" I laughed and said, Yes, that's why I'm here--and the guy who wrote it is an old friend of mine.

Anyway, thought you'd appreciate the story!

Cheers,
Brad (C.)

dnanian
06-28-2006, 01:32 PM
Hey, Brad -- good to see you here!

Your story wouldn't be fantasy if you were on an Intel Mac: Intel Macs can boot from GUID, and so you'd be able to format and store a partition on it that both machines could recognize.

But, PPC Macs can't really do that. While they can recognize and back up to GUID volumes, you can't boot from them.

If the bootability isn't a big deal (to me, it is, since it means I can test my backups and get up much faster), then you can partition as GUID, format the PC one with NTFS (which can't be written to by the Mac, but that shouldn't be a problem), the Mac side with HFS+, and be all set.

You can't really use the same partition, because there's no "high-function" format that works with both. You could purchase additional software to have Windows be able to read/write HFS+, but it's not an inexpensive outlay, and I'm not sure I would trust it with a backup.

Of course, there's another option. You could keep the drive attached to the Mac, format as HFS+, and share it with the PC using SMB/Windows Sharing. The Windows drive would see it as compatible, and the Mac could write directly. No boot for either, of course.

(Remember -- you can boot from a full image backup once restored, just not directly.)

Hopefully that gets us part way to understanding... let me know if you need additional follow-ups.

Brad
06-28-2006, 02:32 PM
PPC Macs [...] can recognize and back up to GUID volumes, but you can't boot from them.

If the bootability isn't a big deal (to me, it is, since it means I can test my backups and get up much faster), then you can partition as GUID, format the PC one with NTFS (which can't be written to by the Mac, but that shouldn't be a problem), the Mac side with HFS+, and be all set.
Ah. Yeah, bootability is a big deal to me too. And I assume by your reply that I can't "partition as APM" and then format the 'other' partition as NTFS (or alternatively, from the PC, do an FDISK, or whatever the equivalent is now on Windows XP, and then format the 'other' partition as APM or HFS+ from the Mac)?

You could keep the drive attached to the Mac, format as HFS+, and share it with the PC using SMB/Windows Sharing.
This doesn't work for us because her laptop is gone most of the day with her when I would be around and (potentially) needing the external drive. Plus, I'd really like for her daily to be bootable. Sounds like we need to spend more money and get her her own 120 GB drive or somesuch.

(Remember -- you can boot from a full image backup once restored, just not directly.)
Yes, this is why I was going to do her weeklies / monthlies (running them all from her machine using SD! of course) as images (or sparses?), myself. Then, she just does the simple thing (push the button) on a daily basis. But I really wanted her to be able to boot from this if disaster strikes. As it is (with your first, non-bootable, solution), we would have to boot from her OS X DVD/CD, then try to copy the image back over from the firewire drive--and if her internal G4 laptop drive is fried, we're stuck at that point. At least, until we get her another drive (I say this because I'm assuming that there's no way to 'convert'--even if I don't need any of my PC data on it at that point and would be willing to throw it away to get her up and running again--that there's no way to 'convert' the external firewire drive to a bootable drive with the image(s) that are on the drive already, right?). (I suppose that maybe I could copy the image file onto my PC's internal hard drive (from the firewire drive), then we re-format the whole firewire drive as HFS+ using the Mac's DVD/CD drive and then could I copy back the image to the firewire drive, thereby making it bootable for her until the new drive shows up for her laptop? But even if theoretically possible, this isn't giving me a warm fuzzy feeling...)

If you have any other ideas (to save us from the 2nd hard drive or buying her an Intel Mac!), but still get me my fantasy, I'm all ears. :D

Thanks, and great 'seeing you' here too! ~ Brad

dnanian
06-28-2006, 03:06 PM
The PC doesn't recognize APM, so that won't work as far as I know. It won't recognize the disk.

It really sounds like you should get another drive, though, Brad... it'll make it easier for both of you to back up, too, since you'll be able to do it at will, even if the other person is mid-backup.

iGreg
07-16-2006, 11:55 PM
Yes, as long as the partitioning scheme is native to the Mac. In general, you should partition using "APM", unless your use is exclusively Intel-Mac, in which case you can use GUID.

What does "APM" mean?

dnanian
07-17-2006, 12:06 AM
Apple Partition Map.

waynewhitlow
07-25-2006, 04:15 PM
I have a similar question on backing up from two macs. I have a iMac (Intel Duo) and a G4 (PPC). How do I partion the backup drive (IOmega) for the different drives? Can they both be bootable?

waynewhitlow
07-25-2006, 04:17 PM
The iMac (Intel Duo) is running 10.4.7 while the G4 (PPC) is running 10.3.9.

dnanian
07-25-2006, 04:27 PM
Use Disk Utility to partition, using "Apple Partition Map" as the partition type (click Options in the partition tab). That will allow both the Intel and the PPC Mac to boot from their own respective partition.

Should work fine!

Ozir
07-27-2006, 09:29 AM
Use Disk Utility to partition, using "Apple Partition Map" as the partition type (click Options in the partition tab). That will allow both the Intel and the PPC Mac to boot from their own respective partition.

Should work fine!

Hi Dave,

Just for clarification...

An Intel iMac will be able to boot off a GUID or APM. A PPC Mac cannot boot from a GUID... only from a APM.

Please confirm.

Thanks.

dnanian
07-27-2006, 09:56 AM
That's correct. An internal drive for an Intel Mac should be formatted as GUID. But, external drives can be GUID or APM.

robaledal
07-30-2006, 01:13 PM
Am I correct in drawing the following (pessimistic) conclusion from this discussion? :(

It is NOT possible to partition a drive in such a manner that
Some partions are in Mac format and can be used to boot the Mac.
Other partitions are in a format that can be recognized and used on a PC.

(Slightly more optimistic :o ) It may be posssible to share the drive between a PC and Mac if bootability on the Mac is not needed.

dnanian
07-30-2006, 01:40 PM
If you don't need things to be bootable, and you don't care whether or the Mac data can be read by the PC, you can -- as of a recent Tiger revision -- use the PC's partition table scheme (MPT) and format an HFS+ partition on it.

You cannot boot from this partition, but the data's all there, so you can restore via alternate means.

bernphys
04-11-2012, 12:10 PM
I have two partitions on my external disk.

I have used one partition to make the bootable disk for my system.

My question is: Can I backup one folder to the other partition without it being bootable by using SuperDuper...otherwise it seems to me that I would have to use Silverkeeper or something else.

Thanks

Bernard Murphy

dnanian
04-11-2012, 12:19 PM
You can. Send me some support email and I'll provide some instruction.

bernphys
04-11-2012, 03:48 PM
Thanks D...I don't understand what you want me to send you.

Bernard

dnanian
04-11-2012, 04:43 PM
An email with the same question. :)