Can I install safely Ubuntu on my Mac?

Question

I have some questions related with Ubuntu. I have an iMac, with OS X Lion and Windows 7 installed. So, can I install Ubuntu alongside Mac and Windows without any problems? Can I resize my Mac's partition later?

Also, my keyboard doesn't seems to work... :/

My iMac is a Late 2009 with 4 GB of RAM.

Solution

This sonuds like a good reason to take caution when installing on a Mac.

From https://help.ubuntu.com/community/UEFIBooting

Caution for Mac owners

From Ubuntu 11.04 onwards (x86_64 only), the ISO CD supports UEFI booting and the Ubuntu installer will try to set up the bootloader for (U)EFI boot. But the installer formats the EFI System Partition to FAT16 (even if the filesystem is non-empty) and also uses efibootmgr, therefore Intel Macs may fail to boot due to corrupted firmware. This feature is not recommended on Mac models because it can corrupt the firmware. You will need to reflash the firmware to repair it.

On Macs use only the Mac alternate ISO CD

Mactel support pages, list what works and what dosen't and version used for mac type, https://wiki.ubuntu.com/MactelSupportTeam/CommunityHelpPages

Mac triple boot how-to https://help.ubuntu.com/community/MacBook/TripleBoot

Comments

[harisibrahimkv]

I'm not a MAC user, but as for resizing your partition, do try downloading Gparted.

[Xerz]

Resizing is no problem, I know how to do it. What I want to say is what can happen if I resize after installing Ubuntu.

[czifro]

depending on big you hard drive is and how much space you have I would just give it 50-60 gb which is more than enough seeing how it needs less than 20 gb, that's with live cd, with wubi, even less.

[Xerz]

The problem related with installing now Ubuntu, is that Mac use EFI instead of BIOS.

[Xerz]

I have a question: as there are no custom ISOs for Ubuntu 12.04, can I avoid the formatting of the UEFI partition, for example, booting with BIOS?

[Mateo]

Hmm, looks like they aren't listed on the main site, and the link on the cdimage site is down, so here is a mirror link mirror.iawnet.sandia.gov/ubuntu-iso/DVDs/ubuntu/12.04/releas‌​e

[Xerz]

OK, this ISO works. This is what I most like about Ubuntu: its community. Thanks! :)

[Eliah Kagan]

Update: This critical bug was fixed. (A while ago, actually. No version of Ubuntu after 11.04 was affected; the UEFIBooting page has been updated to reflect this.) Related: This question about whether or not this bug is still an issue. We probably should dupe one to the other. On the other hand, this question, and this answer, are a bit broader, pertaining to compatibility also.