Setting 2 HDD's as one?

[JesterDev]

I think I just hosed my suse box.. I was just trying to format a second HDD, and it seems I screwed up somewhere.. So anyway I heard that is is possible to have 2 HDD's act as one. What exactly do I need to do for this to work? Or am I just dreaming...

I'm thinking I could just install on one, and use the other has my /home ?

Both are 120gb drives so it seems like a waste to just to do it like that. Can this even be done from the installation?

Just copying files over to a backup partition now before I re-install so I thought I'd ask while waiting.

I had this window open while formatting but this is all that works. Everything else 'cannot be found..' I can't even extract k3b in order to burn a knoppix cd. :rolleyes:

[psi42]

Originally posted by JesterDev
I think I just hosed my suse box.. I was just trying to format a second HDD, and it seems I screwed up somewhere.. So anyway I heard that is is possible to have 2 HDD's act as one. What exactly do I need to do for this to work? Or am I just dreaming...

What you're looking for is RAID. I haven't set up a RAID array before, so I can't really help you there.


I'm thinking I could just install on one, and use the other has my /home ?

Sure. Or you could put /usr on one drive and everything else on the other.

:)

~psi42

[JesterDev]

Well perhaps a RAID array is bit to complicated for me at the moment. I'm ready to reboot anyway so maybe I'll try it another day. Thanks for the help though.

[knute]

Psi,
I'm not sure that he's asking about RAID. I think that it's more of a filesystem question.

Jester,

I'm not sure of your expertise, so I'm clarifying here. Raid will set up your box with redundancy so that it will be just an array rather than hda1 or hdb1. I'm not sure what the RAID syntax is because I haven't used it before.

Now, to what I think you are asking. Linux doesn't really care where your partitions are, just so long as it knows where to look for a particular partition.
In windows you have a C: drive, and a D: drive, and an A: drive, etc...

In linux, you only have the filesystem which starts at "/" and everything else is hung off of that.
/etc is where most if not all of your global config files are located.
/usr is where most of your software and commands are stored.
/bin and /sbin are where the commands necessary to boot the system are stored.
/var is for information that changes on a regular basis.
/home is where user specific configs/files are located.

Ok. now most extra mount points are stored in /mnt, but I have my dvd drive in /dvd

The main file to see this is /etc/fstab. It is where linux looks for the mount points as they are called.
Mount points can be used for more than just partitions on the computer, they can be used for network shares as well (something like a shared network drive that is connected on boot in windows).

Does that answer your question?

[Alex Cavnar, aka alc6379]

It's called LVM-- logical volume manager.

What you're looking for is spanning-- spreading one filesystem across multiple disks. It has also been equated to RAID 0, but you could use disks of unequal sizes and interfaces. (eg, a 4.3GB SCSI and a 120GB IDE drive could form a single volume)

The company that puts it out for Linux is Sistina (http://www.sistina.com/products_lvm.htm). The HOWTO can be found at tldp.org:
http://tldp.org/HOWTO/LVM-HOWTO/

I can tell you, I've run LVMs before-- they're pretty neat! They virtualize your storage space into units, which you can chunk up as you please. In fact, you can even dynamically resize partitions to more effectively utilize disk space, even after the logical volumes have been created. There's only one caveat, though-- there is absolutely NO fault tolerance-- if one drive out of the entire VG (volume group) goes bad, then you've lost all of your data on all of your logical volumes in the VG. If you want to run one of these setups, make DARN sure that you have a good backup strategy in case of failure.

RAID would work, but it would kind of be shoehorning it. RAID's best when either speed or redundancy is a concern. LVM is great when either disk space usage or increased total disk capacity takes precedence in your application.

[JesterDev]

Thanks everyone for the help. I guess I have allot more to learn then I thought. I tried to setup a RAID array during install but could not quite figure out how to do it and still have a / partition..

Thanks for the info knute. I have a better understanding of how it all comes together now.

And thanks Alex, that is more what I am looking for. I'll have to look into that soon. Right now I am just happy to have everything installed again. Just have to set everything back up again..

In case anyones interested in what happened I formatted the second drive and set it as /usr. :rolleyes: I swear I didn't intend to do that, but eitherway, you live and you learn. I suppose I could have just fixed that without re-installing.
Right now I have hda as / and hdb as /usr.. I don't suppose it's the best setup but it should work for now.