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Re: 2 issues Raid, Netatalk

Hi all, 
Gary Sardine has been most helpful with the RAID
issue. When I replied to him after his first post, I
forgot to say reply all and the subsequent
conversation has been between him and me. I thought I
would post the information he has shared for
everyone's benefit. I may not get to attempting to set
it up for a couple of weeks. Here are his helpful
>On Sun, 2002-12-15 at 05:46, David Tisdell wrote:
> Thanks Gary.

No problem.

> Two points of clarification:
> 1) I would go ahead and install and create mount
> points etc on a single drive (or multiple drives if
> wanted /home on a separate drive) and then add raid
> support after the fact yes?

Since you are interested in RAID1, this might work,
I have never tried it.  I do want to mention before I
forget that you really should try to have each drive
its own IDE channel for software RAID.  With RAID1
not as big a deal as with R0 or R5, though.

I expect it might work to install in a single drive,
duplicate the partition scheme in a second (mirror)
drive, then create /etc/raidtab and use mkraid to make
the RAID1 devices.  I don't know.

What I do with Debian is kind of cheating (becaused I
work at a GNU/Linux PC shop, and we have lots of
at our disposal), but it might give you ideas.

We have an IDE drive that holds a good Debian
It boots a kernel that will drive any piece of
we offer.  We boot a new system (getting Debian) off
this hard drive, hanging the hard drive off of a
PCI IDE card, so it is out of the way of the real
drives.  We then partition and format the real system
drives.  In the case of a system entirely on RAID1:

o make partition schemes for each of two hard drives
  identical (software RAID mirrors partitions, not
o create entries in /etc/raidtab (using an example
  we keep around for reference, changing only things
  raid-level and device)
o use mkraid to make the /dev/mdN software RAID
o formate the software RAID devices /dev/mdN:

  + use mkreiserfs /dev/mdN for ReiserFS.
  + use mke2fs /dev/mdN for ext2
  + use mke2fs -j /dev/mdN for ext3
  + use mkfs.xfs /dev/mdN for SGI's XFS file system.

o Mount the new system inside of /mnt.  e.g., If / is
  RAID1 using /dev/md0 and /home is separate, RAID1
  /dev/md1, do:

# mount /dev/md0 /mnt
# mkdir /mnt/home
# mount /dev/hd1 /mnt/home

  The purpose is to _copy_ the running file system
(off of
  our stock Debian drive) into the new devices.  We
drop to
  run level 1 and use cp with certain flags to do this
  Next, we create directories in /mnt that we will not

# cd /mnt ; mkdir cdrom floppy proc mnt

o Finally, be sure to be in run level 1 (we do all of
the above
  in run level 1), and do:

# cd / ; cp -a dir1 dir2 ... mnt

  dir1 dir2 ... ranges over every top level directory
(e.g. usr
  home lib ...) except for cdrom floppy proc and mnt,
which we
  do _not_ want to cp).

If I did not have a stock Debian hard drive and a PCI
IDE card
available for this, I would switch to a shell early in
a Debian
installation and create software RAID devices by hand,
them (mke2fs -j or whatever), and mount them.

Don't forget, you will need software RAID support
available in
the kernel.  If you will be booting off of a RAID1
array, it's
easiest to compile RAID1 support in rather than using
a module
(else you'll need to use initrd, which Red Hat sets up
the scenes, and Debian does not).

My Debian PPC system has mac-fdisk and not pfdisk;
mac-fdisk is
a lot like fdisk for i386.


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