On Monday 28 February 2005 02:06 am, Richard Bos wrote:
I'm looking into RAID, and as such I started to read the suse manual and the raid howto on the web. I still have some questions that someone on this list can answer.
1) Is it possible to add a soft raid after installation? The system I want to extend with raid (raid 1) is already up and running on single disk system (it has 2 disks).
Yes. But... I would recommend you avoid putting your boot device on a software raid for your first go-around. It can be done, but it requires more learning. Most raids I setup are software raids, and the root drive (with boot partition and linux software) are all non-raided, as is swap. All mission data files, is on the raid. I have a batch job copy certain files from /etc to a backup location on the raid nightly. That way, I can upgrade the OS, without having to involve the raid. Yes, my OS drive is not protected, but it is fairly easy to rebuild, and I keep copies of critical files. Converting a single partition to raid after the fact is fairly easy, sort of like what happens should one raid drive fail. Put both partitions in the raid (man mdadm ) but put the empty drive in as a spare. As soon as the raid fires up it will replicate the data from the live drive to the empty.
2) How does one enable hardware raid. The motherboard has an onboard hardware raid controller. The controller does not really seem to be supported by linux (Promise 378). Anyway, I ask this out of interest ;) In case of hardware should it be done via the bios or completely different?
If drivers are not present in your distro, I would consider software raid instead. Hardware raid always has to fight the driver wars, and it never gets any better than the day it was first installed. Software raid benefits from every processor/memory upgrade along the way, and gets better. Some raid controllers can be jumper-ed to be regular dual channel ide controllers. That's the way I've been using mine. -- _____________________________________ John Andersen