Software Raid 5 in Fedora 9 How To?

[Twowolves2000]

Hello,

I'm a linux noob, messed w/mandrake and Knoppix in the past, but have forgotten what I'd learned, and returning now. My interest now is the home server setup, and Amahi is a beautiful answer for linux, sounds like it preconfigs samba and other services that have been command line guru only previously..awesome! Let me state that I'm primarily after the security of raid 5 for storage. I've been in IT for a number of years and learned the beauty of raid 5 and data being safe for all but the most extreme cases, watched raids that were limping rebuild 1 drive, then a 2nd drive w/no loss at all! So, I've always wanted to setup the homeserver w/raid 5 that could grow and follow me through time, expansions/additions as desired, but especially upon drive failure. I want to keep all music, alot of movies, and 3-4 network pc's worth of weekly backup. Will linux software raid still do this? My thinking was I don't need absolute performance, just enough to stream music and HD movies from it w/the safety. Now, first question to all the linuxheads out there(and that's not derogatory just a techie label for what ya do) that know it's capabilities, will linux's software raid uphold the same redundancy and failure recovery w/ it's raid 5 support and then will fedora 9?

I have an htpc box I am using to grow this, it includes: a gigabyte 9400 chipset mobo, 4Gb 1066 ram, Intel Q6600 cpu, 3x 1Tb Seagate 7200rpm sata drive's. I was wishing I could just make a 2Tb raid 5 out of that and install OS and media on that, so there won't be any unrecoverable crashes or moves. Is this plausible and doable w/linux and Amahi? I am expecting there to be some commands to build the raid then install on it, and need those commands too >.< Thanks in advance for any advice and insight!

-Old Wolf

[nemolomen]

Hi Twowolves2000,

I haven't ever set up a RAID, but I have looked into it in the past. Here is some information that I've found.

http://wiki.amahi.org/index.php/Software_RAID

http://linux-raid.osdl.org/index.php/Linux_Raid will give you all the information you could possibly want on Linux RAID.

Good luck,

nemolomen

[Twowolves2000]

Thank you very much for the links, absorbing now

[Twowolves2000]

aarg! ok, I've tried the onboard sata controller set to raid 5 and ahci and it won't boot after completing the install either way, and that's w/o doing any software raid setup. I was thinking the controller might actually work, as once you set it to raid5 you hear all the drives chattering like it's equalizing any data already, but I guess not. So being that you don't load a linux driver for the controller..or do you?, or do I just do the software raid setup anyway? I tried the mdadm from a shell from the dvd when it didn't boot, and it won't let me do the mdadm --create... w/partition exists on sda1 and both sdb and sdc are busy/can't access them when I was in raid 5. I guess I'll try it in ahci and see what happens. bleh, I guess I've gotten too familiar w/microshaft's ways Any ideas?.. help please!?

Thanks,
Old Wolf

[nemolomen]

Hi Twowolves2000,

Sorry to hear you're having so much trouble. Although, from what I've read, the general idea is that you don't use RAID hardware in RAID mode UNLESS the hardware vendor provides drivers for your specific distro. So, you use your RAID hardware simply as a drive controller and use software RAID to take care of the details. Yes, the software RAID will be slower, but it will work.

Like I said before, I've never done the whole RAID thing, but I did sleep in a Holiday Inn Express las....sorry. I meant to say I have read about it quite a bit. My point is that I'm not an expert, but hopefully I can help you.

If I read what you wrote correctly, it sounds like you tried the hardware way but it didn't work, and then without undoing the hardware way , you tried the software way and it didn't work either.

At this point, I have two suggestions. First, I suggest you get everything back to where it was before you started and only try the software way.

My other suggestion is to keep a journal of what you do and the results, it is great for figuring out what you did wrong. I have a journal for my Amahi server and whenever I install new software or hardware, I write write down the steps I take so that 6 months later I can repeat what I did before with much less trial and error. I also write the url's of where I found information and, in some cases, I staple the contents of a tutorial I followed right into the notebook.

Oh, and 'man' is your friend. And so is "Fedora Linux Toolbox" from Wiley Publishing.

Let me know how it goes,

nemolomen

[Twowolves2000]

nemolomen, thanks for your help, but I got it working and what you suggested is what worked. I'm writing this on the box in question. However, I have no idea if what is working is what I want or will work past a day heh. This does give me access to IRC though, so I've broached the subject out there as well. That said, I essentially took the defaults it offered w/LVM and made software raid 5 on sda/b/c out of all open space, and created md0 after that /shrug..it got me here hehe. Not sure if these will help at all, I'm thinking you'll need a config file of some sort, but here's the first two screenies that might verify my thoughts:





At this point I'm not sure what would be of more use. After giving up on hdware support, I set it to AHCI in the bios so they're treated as individuals and the setup at least saw them right off. I think I've messed my amahi install up in a couple of places and trying to correct that now. More in a bit.

Thanks,
Wolf