I have an unRAID box with 6 SATA drives. I want to install a couple more drives and install another OS (Windows Home Server) for testing purposes.

 

If I have the USB key set as the primary boot device and the HD as 2nd, can I pull this off...ie, if the key is present it boots to unRAID and ignores the 2 WHS drives and if the key is not present it'll boot to WHS on the HD and ignore the unRAID formatted drives?

 

Anyone try anything like this? Any Gotchas?

I thought about this quite awhile ago, as I too wanted dual use of my limited resources.  I would love to have a 3 personality machine: good working girl during the day (running WinXP as an ordinary workstation), party girl during the evening (running unRAID as a media server), and backup geek in the early morning (unRAID again, as a backup server).  I never got around to trying it though.

 

I came up with 3 issues that I would have to deal with, none insurmountable.  There may be others.

  1. Managing the dual booting: this is probably the easiest, as sooner or later one of our very knowledgeable users will work out a method and share it with us.  It could be based on your 'existence of flash drive', or it could use one of the boot menu/director programs out there, or it could be an enhancement of the current unRAID startup menu.  I haven't had time to play with these ideas yet.

  2. Protecting the drives:  On the Windows side, WinXP at least will ignore the ReiserFS unRAID drives.  On the unRAID side, I would like to request a feature from Tom, a way to mark specified drives as untouchable, a way to put them in a 'no spin zone'.  The absolute only access to them would be to send them a spindown command, and then never access them again under any circumstances.  Alternatively and better for some users, create a special 'transfer zone', where the drives are not allowed to be assigned by unRAID, but they can be accessed for file transfer/import purposes.

  3. CMOS Date and time:  It's my understanding (I could be wrong) that unRAID assumes that the saved-in-CMOS timestamp is UTC based, and that that is fairly normal in the 'nix world.  UnRAID then uses the timezone info we configure to properly display the current time.  Unfortunately, we in the Windows world save the current time into CMOS, and Windows uses the timezone info to convert it for internal use.  So dual booting means that one or the other operating system will display a time that is hours off.  I have wanted to ask Tom if he could add an option to consider the CMOS time as local, and use the configured timezone info to convert it to UTC for his internal use.  That should make the times consistent for dual booters.  The local CMOS option should default to preserve backward compatibility of current unRAID systems.

 

Thanks for those observations Rob

 

1 - for my purposes, I'm thinking that the decsion on which OS to boot would merely be based on the existence of the USB key. If it's not there, it moves on to a HD boot. I see no reason why this wouldn't work, but then who knows? I'd be curious to know if anyone has tried this.

 

2 - Yeah, I assumed that booting into a Windows environment would be relatively safe and the ResierFS disks would be ignored (though in WHS one would need to be careful to not let the OS claim them and format them for its own storage) but I wasn't (and I'm still not) sure how the NTFS volumes will be treated by unRAID. I'd have to assume that unRAID would just ignore those disks too, unless they were imported and added to the array. Wouldnt they? or will unRAID pitch a fit at the existence of foreign drives?

 

3 - Interesting, and I never would have thought of that. I'm not sure that this would be a deal-breaker for me, as the dual-boot situation would be for testing/comparison. One would eventually win out and I'd not be dual-booting anymore.

 

Mostly I'm concerned about protecting the integrity of the current unRAID data. Anything on the WHS side would be expendable, unless I ultimately decided to move that way.

You might also read this thread, for an alternative direction and ideas:  http://lime-technology.com/forum/index.php?topic=1215.0.

 

1 - for my purposes, I'm thinking that the decsion on which OS to boot would merely be based on the existence of the USB key. If it's not there, it moves on to a HD boot. I see no reason why this wouldn't work, but then who knows? I'd be curious to know if anyone has tried this.

 

And it's probably just that simple.  I have a sneaking suspicion I am forgetting something, though.  In the past, some BIOS's would adjust the boot order under some circumstances.  BIOS: "Hmmm...  it says boot from USB device first, but I don't see one, and here's a perfectly good bootable active primary partition, so I'll just 'correct' the boot order for this user".  And there you'd have the machine suddenly thinking it was smarter than its human, and who knows where that might end!

 

2 - Yeah, I assumed that booting into a Windows environment would be relatively safe and the ResierFS disks would be ignored (though in WHS one would need to be careful to not let the OS claim them and format them for its own storage) but I wasn't (and I'm still not) sure how the NTFS volumes will be treated by unRAID. I'd have to assume that unRAID would just ignore those disks too, unless they were imported and added to the array. Wouldnt they? or will unRAID pitch a fit at the existence of foreign drives?

 

I probably over-complicated this part too.  I was concerned more about avoiding any risk of wrong assignment.  As far as I know, unRAID won't touch a drive that is not assigned, so if you are a very careful person, then there should be no problem.  I would personally prefer some guard rails here, so that months from now, in a forgetful moment, when I might be adding drives, or someone else mis-interpreting my notes, would assign my Windows drive to unRAID and it would quickly and unrecoverably be cleared.