Re: [gentoo-user] Re: RAID on new install

[Mark Knecht]

On Mon, Apr 4, 2011 at 7:14 AM, James <wireless@×××××××××××.com> wrote:
> Mark Knecht <markknecht <at> gmail.com> writes:
>
>
>>    Depending on what you are putting onto your RAID watch carefully
>> what choices you make for SuperBlock type as well as being aware of
>> possible md name changes between the install environment and your
>> first real boot.
>
> Nice to know.
>
>
> (I think I'm going to stick with ext4 for now).
> (BTRFS later...) I have 2 identical 2T seagate drives.
> The main purpose is to run an php and apache
> server  and use kde (kiosk) to display network status
> using jffnms (graphical) and postgresql-9.
>
> Raid 1 Mirroring for most if not all partitions.
> Think of it as a station where everyone can view
> the network conditions, as users, but I remote
> admin the system. No logins except via the limited
> kiosk  to just view/query the network, or a remote
> connection to the server.
>
>
> These Docs I listed are dated?
> Gentoo.wiki.com is finally back up.  These
> 2 docs reference each other....
>
> http://en.gentoo-wiki.com/wiki/Software_RAID_Install
> and
> http://en.gentoo-wiki.com/wiki/RAID/Software
>
> Which one is more accurate or the best one
> to mostly follow? (that's what I'm trying to
> figure out now.)
>
> I do appreciate any and all feedback.
>
>
> James
>
>
>
>
> Which guide do you think is better, for my needs?

I suspect that a 2-drive RAID1 is a good solution for you. I
personally doubt that ext4 vs ext3 will make any difference. I use
both myself. I wouldn't personally touch any new file system type when
trying to learn to do RAID. Save that for some future date.

Unfortunately neither link is responding as I write this, but my
recent (last 6 months) experience with the Gentoo RAID documents is
that none of them result in a completely working system first time
through. (Again, I cannot look at these links right now so please
excuse my not knowing about any recent changes.)

1) They are all based on the oldest SuperBlock 0.9 format which, if I
remember correctly, is not the default SuperBlock format that mdadm
creates these days.

2) I was able to build a SB-0.9 system using the same docs. I was only
able to build a working SB-1.2 by also including an initramfs:

http://en.gentoo-wiki.com/wiki/Initramfs

Pay special attention to note about building certain things static or
the initramfs won't work for you. Also, include all the tools you can
that will help with debugging why you cannot mount the root file
system. My experience is that you won't be able to for the first day
and you'll find the tools invaluable in getting it worked out.

3) It might be frustrating, but I'd suggest some testing of the RAID
before the actual install. Boot the install disk, build the RAID, then
learn to use mdadm examine & detail commands to understand then names
your RAIDs have. Pay attention to what the name of the machine will
eventually be. Consider renaming the RAIDs before the real Gentoo
install so that when you boot the real install it can find them.

I run RAID these days on almost all my machines. I just got a laptop
with 2 500GB hard drives which will become a 2-drive RAID1 system when
I get around to doing the work.

I hope this response is at least somewhat helpful.

Good luck,
Mark