JBOD question
 

HI all,

I've been given a couple HDDs (80 and 120GB) which I'd like to combine with my original HDD (320GB) in wich I already have and installed Gentoo box.

I've been searching around and the option I found I want is to set up a RAID configuration in JBOD setup (LVM setup) to make the 3 HDDs appear as a single unit.

My question is: if I setup the JBOD config with the 3 HDDs, will I lose all the data stored on those hard drives?

I think you are confusing your acronyms. JBOD is "Just a Bunch of Disks", RAID is a redundant array, and LVM is a Logical Volume Managed device.

If you have data on the three disks you're wanting to use, you need to mount them singly, under three different mount points. If you want them to be in a logical volume group, you'll have to define the group, and then add the volumes. When you do this, you'll have to format them, so the free space can be added to the LVM. The partition types will have to change to be LVM. After you build the LV, you can format it and mount it as a single drive.

There may be another way to do it, though, but I think that changing the file system type will nuke the data.

What I'd like to have is a single mount point with all the 3 hard drives so I don't have to be looking through 3 hard drives for something I need. And this without having to lose all the data.

I agree maybe I have misunderstood the acronyms...Sorry for that, but I'm completely noob at those things.

No problem, but I didn't want to mis-understand the question either. :)

I am fairly certain that you'll have to blow them away to make one big LVM out of them. Use caution, though...if you lose one volume of that LVM, the whole thing will be un-readable.

Well, that's definitely not an option for me. Is there any other config that might "concatenate" the harddrives without compromising the whole data if one disks goes bad?

If you want something that's fairly bulletproof, you'll want to go with a RAID configuration, using a hardware controller. I tend to lean towards RAID5, with an online spare. You need at least 4 drives to make that work, but if one drive dies, things go right on working, and you can replace the spare later. You CAN do it through software, but it's kinda slow...SATA RAID5 controllers aren't much, and drives are cheap these days.

You can do mirroring, but I've had several instances where one drive will croak, and corrupt the mirror, leaving me with a dead system, but your mileage may vary. You also need drives that are all the same size, to make things work best.

Thanks for the help and suggestions. I'm on 1770GB right now:

- Internal HDD 320GB
- Internal HDD 120GB (USB box)
- Internal HDD 80GB (USB box)
- External HDD 250GB
- External HDD 1TB

What I'd like is to take both 120 and 80GB disks and make them work together with the interal 320GB. If I setup a RAID5, (if I'm coorect) I'll shrink the RAID to 80GB only... and making a RAID0 is way too dangerous for me to try. I guess I'll have to live with my desk full of HDD boxes :P

Thanks a lot for your information.