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Some doubts about Fusion Drive
- Thread starter iRock1
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The article is about how to configure a 3TB disk to be compatible with the Windows 2.2TB restriction, however the 4 partition issue is present with any disk size.
From the link above:
http://www.twocanoes.com/support/wi...-tb-or-larger)-drive-in-lion-(10.7)-and-later
In order to boot Windows on a Mac, the Windows partition has to be created in a very specific place, and has a few more limitations than on a standard PC. The Boot Camp partition must be the last used partition among the first four partitions. Any partition beyond the first four partitions will not be recognized by Windows. In Lion (10.7) and Mountain Lion (10.8), there are two hidden partitions that take up the first and third slots. The first slot is taken up by the EFI partition, which is required by the standard partition scheme (GUID) that Mac OS X uses. The second slot is used by Mac OS X. The third slot is taken up by the Recovery partition. Note in the below diagram that Windows is the last in the first four partitions. Also note that Disk Utility on OS X will hide the EFI and Recovery partitions.
That article is EXACTLY what you want to do ... but for a different reason.
They are creating a 3-OS partitioning scheme (just as you want to do) because they are forced to do so by the Windows 2.2TB issue on their 3TB drive. So they put Windows on the middle partition (just as you need to do) so as to only have 4-partitions to reach the Windows installation (including the hidden partitions). This leaves the last partition (remaining disk space) free for whatever the user wants (in your case ... for Linux).
They are using a hard disk ... you want to use a SSD ... same procedure. If you want to then create a Fusion drive, simply use the common procedures but use the SSD-PartitionID (first partition of the three you created) joined with the HD-DiskID ... and you are done.
I guess you would want the biggest and fastest SSD that you can afford, given that you want 3 operating systems on it. I would probably get at least 500GB ... and the newer EVO and M500 drives are reasonably fast and much less expensive than equivalent top end 840 Pro drives, and they are available in 980GB and 1TB models for around $500 (US ... don't know where you are located). A 500GB would allow each os 150GB or so, and you would want at least 128GB for Fusion (preferably more IMHO). A lot depends on how you intend to store programs/data for each OS and if it is to be on the SSD or additional partitions on the 1TB HD.
If you are running this external via. Thunderbolt to your iMac, you need to get an enclosure that is "Windows bootable" (or a complete Thunderbolt SSD). If you are going to put it internal to your iMac, you need to determine the proper form factor (2.5" SATA or blade type) for your generation iMac (you should have no Windows bootable issues internal).
EDIT: I see you have a 2009 iMac with SATA-II interfaces.
You can use a SATA-II 2.5" SSD drive in the optical bay to save a bit of money (or a SATA-III will work too). You can get optical bay mounting hardware (optibay), or simply velcro the lightweight SSD in there.
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Well, it's not THAT much for a 1 TB SSD, but still... I'll probably go with something around 500 GB. If I organize my partitions well, it shouldn't be a problem (at least until Windows runs out of space, in which case I understand there's nothing to do but to create a new and bigger partition with Boot Camp).
Yes, as I stated before the plan here is to replace the optical drive and put a caddy instead. Since it's not a particularly user-friendly mod, I wanted to be extra sure about the right SSD.
Anyway, huge thanks for all the support.
I was on the fence before I finally went with an Evo. I decided that (for the money) it was more important to have more flash, even if it wasn't quite as fast. My choice was between a 120GB Pro and 250GB Evo. I went with the latter and am very happy.