LinuxQuestions.org - Some advise on RAID 1 pls

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Some advise on RAID 1 pls

Hi,

I'm building an Ubuntu Server 12.04 minimal based machine and have ordered the machine with 2 identical HDD (SATA) of 500GB each.

My aim is to have RAID1 for redundancy, but it's going to be entirely software RAID (no RAID controller).

Firstly, am I to install the RAID during Ubuntu installation or would the RAID be installed after Ubuntu is setup?

Secondly, does RAID 1 mirror a drive or a partition?

Quote:

Originally Posted by eantoranz (Post 4861272)

This should help: http://linuxconfig.org/Linux_Software_Raid_1_Setup

Thanks, eantoranz.
I really needed such a guide,

Quote:

Originally Posted by eantoranz (Post 4861272)

This should help: http://linuxconfig.org/Linux_Software_Raid_1_Setup

I'm trying to follow instructions on the above guide to setup RAID1 (my PC has one 80GB and the other is a 320GB. I've installed Ubuntu Server 12.04 on the 80GB which should RAID1 (mirror) to the 320GB. Both are SATA).

However, I've reached a stage where we're setting modules to load at boot time and I seem to be getting totally different results from what's expected in the guide.
At stage 4.2 in the guide,

Quote:

lsmod | grep raid1

results to

Code:

raid1          21056 0

md_mod          70388 1 raid1

However, on my machine I get the following

Code:

raid10          35489 0

raid1          35572 0

If I do

Code:

modprobe md

I get

Code:

FATAL: Module md not found.

Yet, the contents of /etc/modules has the following

Code:

loop

lp

rtc

raid1

md

As per the guide,

Quote:

cat /proc/mdstat

results to

Code:

Personalities : [raid1]

unused devices : <none>

Yet on my PC,

Quote:

cat /proc/mdstat

shows

Code:

Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]

unused devices : <none>

Where could I be going wrong?

Perhaps md is not the name of the module that should be loaded? I don't have any md module in my host (kubuntu 12.10). WHat I do have is an md directory and some raid mods inside. Does it ring any bell?

Code:

/lib/modules/2.6.32-38-generic-pae/kernel/drivers/md/raid0.ko

/lib/modules/2.6.32-38-generic-pae/kernel/drivers/md/raid1.ko

/lib/modules/2.6.32-38-generic-pae/kernel/drivers/md/raid10.ko

/lib/modules/2.6.32-38-generic-pae/kernel/drivers/md/raid456.ko

/lib/modules/2.6.32-38-generic-pae/kernel/drivers/md/raid6_pq.ko

Quote:

Originally Posted by eantoranz (Post 4864548)

Hmm. You're right. They're actually all there and that's where the "Personalities" are being loaded from? So I'm a bit confused now. Are you saying that instead of

Quote:

echo raid1 >> /etc/modules
echo md >> /etc/modules

I need /etc/modules/
to load

Code:

/lib/modules/3.2.0-35-generic/kernel/drivers/md/raid1.ko

I think you should only have raid1 in /etc/modules given that md does not exist (anymore).

Ah, OK.
So it's like md is taken care of in the /lib/modules/3.2.0-35-generic/kernel/drivers/ ?

and I'm proceeding onto the next level - Prepare sdb for RAID.

Well, I was getting difficulty going through, as many of my instances were different from what was shown in the guide, so I decided to do things from scratch (LITERALLY SCRATCH) and this time followed the official Ubuntu Server documentation on RAID1 (https://help.ubuntu.com/12/04/server...tallation.html) and managed to complete the job.

Now the question arises, is RAID actually working, and if so, is it working OK?
I've been looking at the RAID results from Webmin installed on the machine in question and I've attached some snapshots from Webmin giving the status of RAID (just a reminder, my machine has nonidentical drives: one is an 80GB and the other is a 320GB. I've just used 4GB on each drive for SWAP and 76GB on each drive for the actual stuff. The 360GB has an unused partition of 240GB).
http://i50.tinypic.com/291knkw.jpg
http://i49.tinypic.com/3177fy0.png
http://i46.tinypic.com/123mmbr.png
http://i46.tinypic.com/2ecqbew.png
http://i50.tinypic.com/2llkgid.png
http://i49.tinypic.com/2qk08ao.png

Some advise on this, pls.

cat /proc/mdstat would do, I think