Topic: Adding Mirrored IDE Drives after SME7 Install

[robertmcgill]

I'm pretty new to the whole Linux server world, so please try and go easy on me.....

In a nutshell, I have SME7 RC2 installed and running.  The install was done onto two 300 GB SATA drives hooked into the two SATA plugs on the motherboard.  I guess the default install is for RAID 1 when two similarly or identically sized disks are detected during the install.  That's all good and well and I don't have any issue with the SATA RAID 1 set.

I have two 400 GB IDE drives that I added after the original install and preliminary setup.  I can get them to work fine as single drives generally following a howto that was written for SME6.  However, I want to set them up as RAID 1 as well.  I know they need to be in the same position on separate IDE channels.   But from that point forward, I haven't seen any  instructions that I can follow.  I've read through the various postings in the contribs.org forums and some of the bugtrackers as well, but can't quite make sense out of the process.

Any pointers or suggestions would be greatly appreciated.

[pfloor]

What you are asking as far as I have seen has not been tried before.  It should be possible but very few people here understand lvm.

Go to the bug tracker and see if Shad will help you with this.  Raise a "New Feature Request".  He may or may not have the time but he seems to understand it.  Charlie and Gordon also have a fair amount of knowlege about this.

Good Luck

[jester]

I don't exactly know what it does and i can't test it for you but there is an option: 'manage disk redundancy' (or something similar) in the server console. Maybe that does what you want.

jester.

[pfloor]

I don't exactly know what it does and i can't test it for you but there is an option: 'manage disk redundancy' (or something similar) in the server console. Maybe that does what you want.

jester.

That won't help him.  It is designed to replace failed disks or add disks to an existing array.  He wants to creat a new array and will have to do that by hand as it is not a supported configuration.

Robert, I have a production server with 4 drives that were installed from the beginning.  In this configuration it creates a raid 5 and the performance is superb.  You may want to consider this approach but you should use identical or very similar drives and I just noticed that the old drives are 300MB and the new ones are 400MB.

[robertmcgill]

Thanks for the suggestions, guys!  It may be a while until I have a bit more time to study how to do this.  In the meantime, I'll probably just look into picking up one or two additional 400 GB IDE drives and doing a fresh install with the drives automatically setup as a RAID 5 array as suggested by pfloor.

[icpix]

Robert----
Here my hardware RAID card was installed with all the drive cables unhooked.
Two motherboard SATA drives (RAID1) fitted and the SME7 OS then installed.
Five SATA drives (RAID5) then hooked up to the hardware RAID card.
I fitted six drives but the h/w card has a 2TB limit of which I was unaware!
My Adaptec 2810SA supports the addition/use of drives with differing capacity.
----best wishes, Robert

[tandum]

Robert,
It's dead easy so long as your bios lets you pick the boot disk.

I'll assume the disks are /dev/hda and /dev/hdc.

fdisk /dev/hda and make a primary partition 1 the full size of the disk. Change type to linux auto raid (type fd).  Do the same for /dev/hdc

Then as root do a: mdadm Create /dev/md(x) --create -l raid1 -n 2 /dev/hda1 /dev/hdc1

Make a file system on the array. mkfs -t ext3 /dev/md(x)  

Of course md(x) is an unused md identifier like /dev/md3 and -n 2 means 2 disks total.

man mdadm for more options.

Then add /dev/md(x) to /etc/fstab to mount it on boot like this:

/dev/md3  /home/e-smith/files/ibays/video/files ext3    defaults        1 1

reboot and do a cat /proc/mdstat to seee the status

my /dev/md3 is 3 250gig drives in raid 5.

done..........

[robertmcgill]

tandum--

Thanks for the details.  I'll give this a try as soon as I can and report back how it goes.  

Robert

[tandum]

Should be ok. One thing though, if you mount the array via fstab directly to the samba share as I have done at home and in this example, you won't be able to umount it if you have too without stopping samba as it will always be in use.

Best practice is to mount it elsewhere, /mnt/video_raid for example and create a link from /home/e-smith/files/ibays/video/files to /mnt/video_raid. Might make it easier to manage in a panic situation