Just a general question about Hardware RAID. I guess I was under the impression that I could keep the existing data on my hardrive, create a RAID 1 mirror with a 3ware (with another drive of course), and go on my merry way. But then I read that creating a new array will destroy all the data on the disc! This isn't good at all! In fact it sucks! This true?? If I create a RAID 1 array by putting in my second disk and then hooking both hard drives up to the 3Ware controller and then create a new array, this will wipe out both drives??

Uck... No good!! If so, why isn't it possible to simple begin data construction (mirroring) on the new drive?

With hardware RAID, that is generally true. The idea is you build the hardware RAID before you start using it. You're going about it in a non-standard order, putting the RAID in after it has been in use. The best you could do is copy all of the data off to another drive, create the RAID, then put it back on. That of course assumes the drive just holds data, not the full OS. The 3ware I have (9500 series) supports migrating data from one type of RAID to another, like RAID 5 to RAID 10, but I don't think it supports going from no RAID to some RAID without erasing everything on the disks.

Peace,
JimBass

Crap. If I would have known this I wouldn't have gone to all the trouble of copying a 20GB disk to my 80GB disk in anticipation of installing the array. Now the 80GB may as well just be empty. I guess I could install the other 80GB disk and then create the empty array. Then copy the 20GB disk over to the array. I suppose *that* would work...

Just curious, how is your 3ware array mounted? Just wondering what to expect when I install it in the system and the kernel finds it. I purchased a 7000 series card so the driver is already built into the kernel (2.6.x) I believe, at least that is what I gather from the reading I have done. Did your distro. Just wondering what will happen when I install it. A new mount point created for the array or something??

Is it not possible to build a hardware RAID1 with a missing disk, bring up the software raid with a failed disk under Knoppix, and copy the software RAID to the hardware RAID? I'm assuming he's going from RAID1 to RAID1, of course.

That would work just fine, as long as the data currently on the 80 Gb disk is still the same as on the 20.

My 9500 is supported by all kernels newer than 2.6.14 I believe. The 7000 series is older, and will be supported by all current installs, but as you found, don't assume anything. Check the specifics, you exact model number, and check what kernels support it, then make sure your install disk has at least that kernel or a newer one.

That depends on your distro, which you should have in your profile. If it is Fedora or something like that, it might auto mount, or at least ask you about auto mounting it. That is more of a windows behavior. If you have something like Slackware or Debian, it won't do anything automatically. You'll have to configure the mountpoint. If you install onto the hardware RAID, that would be best of all, but it depends on what you want it to do. Does it hold your OS, or just data? That's a hugely important difference.

In my case, I built a RAID 5 array with the hardware controller before I even installed Debian, then I installed onto the array.

No, it isn't possible to build hardware raid with a missing disk. That is a software raid behavior. If I'm reading his post correctly, he has no RAID on the disk, and wants to add hardware raid after the fact.

Peace,
JimBass

Hey!

Distro I'm running is SuSe 10.2. I really do need to create a profile here... The 80GB disk does currently hold the OS. What I can do is copy it over to my 20GB (there is less than 20GB on the 80GB). Then setup the hardware RAID 1 (get the card installed and setup the array via the 3ware Bios), partition and format the array the EXACT same way the original 80GB drive was, copy the 20GB back to the array, and then finally reinstall GRUB and it *should* boot...

*phew*... But it should be waaaay easier to do this than have to reinstall e-v-e-r-y-t-h-i-n-g.



You are correct in that I have NO raid and I am wanting to add it after everything is installed. Something that, I am learning, is problematic...

Copying everything can be tricky. There was a huge post on the tool "dd". Searching for that may help you. I don't remember who wrote it, but I think it was in the newbie forum, and had over 100 replies.

To be honest, I would reinstall in this case, but it can be done either way. Debian has the ability to list every installed package, so rebuilding a copy of that is trivially easy. I suspect Suse has the same ability, but I don't know for certain. If Suse has that ability, then just make a perfect copy of your home, and have at it. Completely reinstalling will create a new home, and simply trying to dump one version onto another can cause problems.

Peace,
JimBass

Actually I just went through this exact same thing to get everything from the 20GB to the 80GB. Had to use a live distro to copy one drive to the other. Like I said, had I known I would lose the data on my 80GB, I would have waited to do this until I got the card in... Augh... Oh well. Good practice I suppose...

Could use the live partimage CD to copy a partition at a time, it might be a bit faster than using dd..

http://www.partimage.org/Main_Page
http://www.sysresccd.org/