Fedora Core 5 and RAID

[dzongos]

I am new to this RAID stuff, but I bought this server, http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1504243&Tab=2&NoMapp=0

I want to install Fedora Core 5 but it only came with instructions and a floppy with windows information and drivers. I know the way its suppose to work is it writes to both drives at the same time and if one goes out the other starts working. Or something like this. So when one goes out, I replace it and it copies everything back over to the other.

I am not 100% sure of how this all works, but I really want it to work with fedora. If there is a howto or some links someone could give me with more information, I would really appreciate this. Thanks in advance.

[pparks1]

RAID 1 is a mirror. It writes the same data to both of the drives simultaneously, that way if 1 drive fails you still have another drive with the data. Then you can replace the drive and it will copy all of the data from the 1st disk (the one still working) to the new drive that you put back in.

There are two types of RAID, hardware and software based. Hardware RAID is done by the hardware and is the fastest and highest performance RAID that you can get. Software RAID puts a load on the system, but can be done without any special hardware and can work with just about any type of harddrive.

According to the specs of that server, it comes by default in a RAID 1 config and is hot swap. Therefore, when you load FC5, it's really going to see 1 hard drive. The hardware will take care of the RAID, so there is nothing special that you have to do...aside from watching a drive failure light come on and replace the drive. It should work with Fedora no problem.

My company uses HP Proliant servers and we have hundreds configured with RAID1 for the OS. RHEL and CentOS have always worked fine with the hardware RAID that these servers come with.

[dzongos]

Hey, thanks for that reply. I read quite a bit last night about this topic. I decided to just try to install it normally. I installed it and got logged into fedora and I did a df -h and it showed my mount to be 450 GB. I have two 250 gig drives, so I am assuming it switched up on me and didnt do raid 1. Is this really a bad thing? I will back things up constantly off site. How safe is raid 1? Should I work on getting raid 1 working? Thanks for the reply.

[pparks1]

You will want to check and see if you are set up to use RAID 0 (stripe).

With RAID0, it writes part of the file to the first disk and part of the file to the second disk. The advantage of RAID0 is that you get all of the disk space available (200GB+ x 2), and it's very fast since it has 2 drives to read and write from.

The MAJOR DISADVANTAGE of RAID0 is that if EITHER of the 2 drives fail, you will lose ALL of the data. RAID0 is NOT FAULT TOLERANT.


With RAID1, a disadvantage is that you lose 50% of the disk space. So, you would only have about 200GB of space available total with RAID1 since the second disk is a mirror copy of the first. However, RAID1 is truly FAULT TOLERANT so you can handle the loss of a disk.

So, it's up to you. How important is the data? Can you afford to lose everything if 1 drive fails? Do you have time to rebuilt/reload the OS?