From:	Gregory Leblanc <GLeblanc@cu-portland.edu>
To:	"Linux Raid list (E-mail)" <linux-raid@vger.rutgers.edu>
Subject: FAQ update
Date:	Fri, 4 Aug 2000 13:47:23 -0700 

Here's a new version, with a couple of changes.  What other questions get
asked all the time?
	Greg

Linux-RAID FAQ

Gregory Leblanc

              gleblanc (at) cu-portland.edu
   
   Revision History
   Revision v0.02 4 August 2000 Revised by: gml
   Revised a the How do I patch? and the What does /proc/mdstat look
   like? questions.
   Revision v0.01 31 July 2000  Revised by: gml
   Initial draft of this FAQ.
   
   This is a FAQ for the Linux-RAID mailing list, hosted on
   vger.rutgers.edu. It's intended as a supplement to the existing
   Linux-RAID HOWTO, to cover questions that keep occurring on the
   mailing list. PLEASE read this document before your post to the list.
     _________________________________________________________________
   
   1. General
          
        1.1. Where can I find archives for the linux-raid mailing list?
                
   2. Kernel
          
        2.1. I'm running the DooDad Linux Distribution. Do I need to
                patch my kernel to make RAID work?
                
        2.2. How can I tell if I need to patch my kernel?
        2.3. Where can I get the latest RAID patches for my kernel?
        2.4. How do I apply the patch to a kernel that I just downloaded
                from ftp.kernel.org?
                
1. General

   1.1. Where can I find archives for the linux-raid mailing list?
   
   My favorite archives are at Geocrawler.
   
   Other archives are available at
   http://marc.theaimsgroup.com/?l=linux-raid&r=1&w=2
   
   Another archive site is
   http://www.mail-archive.com/linux-raid@vger.rutgers.edu/.
   
2. Kernel

   2.1. I'm running the DooDad Linux Distribution. Do I need to patch my
   kernel to make RAID work?
   
   Well, the short answer is, it depends. Distributions that are keeping
   up to date have the RAID patches included in their kernels. The kernel
   that RedHat distributes, as do some others. If you download a 2.2.x
   kernel from ftp.kernel.org, then you will need to patch your kernel.
   
   2.2. How can I tell if I need to patch my kernel?
   
   The easiest way is to check what's in /proc/mdstat. Here's a sample
   from a 2.2.x kernel, with the RAID patches applied.

[gleblanc@grego1 gleblanc]$ cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid5] [translucent]
read_ahead not set
unused devices: <none>
[gleblanc@grego1 gleblanc]$

   If the contents of /proc/mdstat looks like the above, then you don't
   need to patch your kernel.
   
   Here's a sample from a 2.2.x kernel, without the RAID patches applied.

[root@finch root]$ cat /proc/mdstat
Personalities : [1 linear] [2 raid0] [3 raid1] [4 raid5]
read_ahead not set
md0 : inactive
md1 : inactive
md2 : inactive
md3 : inactive

   If your /proc/mdstat looks like this one, then you need to patch your
   kernel.
   
   2.3. Where can I get the latest RAID patches for my kernel?
   
   The patches for the 2.2.x kernels up to, and including, 2.2.13 are
   available from ftp.kernel.org. Use the kernel patch that most closely
   matches your kernel revision. For example, the 2.2.11 patch can also
   be used on 2.2.12 and 2.2.13.
   
   The patches for 2.2.14 and later kernels are at
   http://people.redhat.com/mingo/raid-patches/. Use the right patch for
   your kernel, these patches haven't worked on other kernel revisions
   yet.
   
   2.4. How do I apply the patch to a kernel that I just downloaded from
   ftp.kernel.org?
   
   First, unpack the kernel into some directory, generally people use
   /usr/src/linux. Change to this directory, and type patch -p1 <
   /path/to/raid-version.patch.
   
   On my RedHat 6.2 system, I decompressed the 2.2.16 kernel into
   /usr/src/linux-2.2.16. From /usr/src/linux-2.2.16, I type in patch -p1
   < /home/gleblanc/raid-2.2.16-A0. Then I rebuild the kernel using make
   menuconfig and related builds.