Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

I'm trying to install Ubuntu 10.04 server edition on a computer with a RAID5 array. The array seems functional from the BIOS standpoint.

The problem arises in the installation when it comes to partitioning the drives. The Ubuntu installer only offers me to "Configure iSCSI volumes". There are no options offered.

It then offers to "Log into iSCSI targets" and asks for an IP and port #. I've tried entering the loopback IP, but it says that no iSCSI targets exist there.

Dont know where to go from here. I havent found any documentation on the subject anywhere on the Ubuntu.com and ubuntuforums.org sites...

Any ideas?

Update 1: I'm running a real hardware RAID using Nvidia CK804 controllers ( 2 of them, 2 HDDs each )

share|improve this question

closed as too localized by Luis Alvarado Mar 14 '13 at 17:16

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

    
What kind of RAID5 array is it?. More clear is it a real hardware RAID or a fakeraid one?. –  Javier Rivera Sep 14 '10 at 13:43
    
I believe that hardware controller is what's called Fakeraid -- the controller presents to the operating system one "special" hard disk, and the operating system has some special drivers for interacting with it. This is useful for Microsoft Windows, which would have problems installing to RAID otherwise (last time I checked). Ubuntu doesn't require this, and can unify the hard disk on their own. However, whether you use softraid or fakeraid, the processing is still being done on the CPU, rather than on dedicated hardware. If you dont dual boot, I'd use softraid in case you swap out the mobo. –  MighMoS Sep 16 '10 at 20:03
add comment

2 Answers 2

The Nvidia CK804 chipset isn't "real" hardware RAID, I'm afraid. It's largely software driven, "fakeRAID". In Ubuntu you'd use the dmraid driver to utilise it.

There is a strong argument for using software RAID instead (performance is very similar and it's much more portable - with caveats). The only reason I'd use fakeRAID over softRAID is if I needed to dual-boot to Windows and needed a shared RAID5 NTFS partition. SoftRAID has better tools, monitoring and support IMO.

Anyway, if you're still interested in dmraid, read through the Ubuntu Help page on FakeRAID. It's not the clearest of pages but it should get you sorted. You also now know the phrases you'll need to search.

On another note, I would also suggest that perhaps the operating system install doesn't need to be on any sort of RAID. I personally leave all the OS data on an SSD and only put parts of user profiles on RAID. There's also a cron job to backup /etc/ to the RAID volume once a day (things don't change that much) and reinstalling is fairly trivial.

share|improve this answer
    
Thanks for the infos. There arent any SATA ports left on the MOBO so i'll resort to using an old IDE disk for the OS. –  Guillaume Sep 16 '10 at 18:29
    
Also, does software raid support hot-swaping disks? –  Guillaume Sep 16 '10 at 18:29
add comment

I found out that Ubuntu installer is confused by some real raid controllers and even thought I can see the partitions in fdisc or gparted, they are not listed by the installer.

To solve this problem I have started the Live CD in 'Try Ubuntu` mode and removed the dmraid package. After that I have started the installer and the partitions were there. You can also press Esc or Shift while the CD boots and from 'F6 - Other options' enable the no dmraid options.

I found uninstalling the dmraid package a better solutions since I don't have to wait for all the boot stepts and detect when the CD is booted.

Here is the related bug report : https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/459054

share|improve this answer
    
Thanks for this info. I'll try this over the weekend and report back on the results. –  Guillaume Nov 10 '10 at 4:27
add comment

Not the answer you're looking for? Browse other questions tagged or ask your own question.