144 lines
5.6 KiB
HTML
144 lines
5.6 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
|
|
<HTML>
|
|
<HEAD>
|
|
<META NAME="GENERATOR" CONTENT="SGML-Tools 1.0.9">
|
|
<TITLE>Root RAID HOWTO cookbook: Configuring the Production RAID system.</TITLE>
|
|
<LINK HREF="Root-RAID-HOWTO-6.html" REL=next>
|
|
<LINK HREF="Root-RAID-HOWTO-4.html" REL=previous>
|
|
<LINK HREF="Root-RAID-HOWTO.html#toc5" REL=contents>
|
|
</HEAD>
|
|
<BODY>
|
|
<A HREF="Root-RAID-HOWTO-6.html">Next</A>
|
|
<A HREF="Root-RAID-HOWTO-4.html">Previous</A>
|
|
<A HREF="Root-RAID-HOWTO.html#toc5">Contents</A>
|
|
<HR>
|
|
<H2><A NAME="s5">5. Configuring the Production RAID system.</A></H2>
|
|
|
|
<P>
|
|
<H2><A NAME="ss5.1">5.1 System specs.</A>
|
|
Two systems with identical motherboards were configured.</H2>
|
|
|
|
<P>
|
|
<PRE>
|
|
Raid-1 Raid-5
|
|
Motherboard: Iwill P55TU dual ide adaptec scsi
|
|
Processor: Intel P200
|
|
Disks: 2ea 7 gig 4 ea Segate 4.2 gig
|
|
Maxtors wide scsii
|
|
</PRE>
|
|
|
|
The disk drives are designated by linux as 'sda' through 'sdd' on the raid5
|
|
system and 'hda' and 'hdc' on the raid1 system.
|
|
<P>
|
|
<H2><A NAME="ss5.2">5.2 Partitioning the hard drives.</A>
|
|
</H2>
|
|
|
|
<P>Since testing a large root mountable RAID array is difficult because
|
|
of the ckraid re-boot problem, I re-partitioned my swap space to include a
|
|
smaller RAID partition for testing purposes, sda6,sdb6,sdc6,sdd6, and
|
|
a small root and /usr/src partition pair for developing and testing
|
|
the raid kernel and tools.
|
|
You may find this helpful.
|
|
<PRE>
|
|
<bf/DEVELOPMENT SYSTEM - RAID5/
|
|
Device System Size Purpose
|
|
|
|
/dev/sda1 dos boot 16 meg boot partition
|
|
* /dev/sda2 extended 130 meg (see below)
|
|
/dev/sda3 linux native 4 gig primary raid5-1
|
|
----------------------sda2------------------------------
|
|
* /dev/sda5 linux swap 113 meg SWAP space
|
|
* /dev/sda6 linux native 16 meg test raid5-1
|
|
========================================================
|
|
/dev/sdb1 dos boot 16 meg boot partition duplicate
|
|
* /dev/sdb2 extended 130 meg (see below)
|
|
/dev/sdb3 linux native 4 gig primary raid5-2
|
|
----------------------sdb2------------------------------
|
|
* /dev/sdb5 linux swap 113 meg SWAP space
|
|
* /dev/sdb6 linux native 16 meg test raid5-2
|
|
========================================================
|
|
* /dev/sdc2 extended 146 meg (see below)
|
|
/dev/sdc3 linux native 4 gig primary raid5-3
|
|
----------------------sdc2------------------------------
|
|
* /dev/sdc5 linux swap 130 meg development root partition
|
|
* /dev/sdc6 linux native 16 meg test raid5-3
|
|
========================================================
|
|
* /dev/sdd2 extended 146 meg (see below)
|
|
/dev/sdd3 linux native 4 gig primary raid5-4
|
|
----------------------sdd2------------------------------
|
|
* /dev/sdd5 linux swap 130 meg development /usr/src
|
|
* /dev/sdd6 linux native 16 meg test raid5-4
|
|
|
|
|
|
<bf/DEVELOPMENT SYSTEM - RAID1/
|
|
Device System Size Purpose
|
|
|
|
/dev/hda1 dos 16meg boot partition
|
|
* /dev/hda2 extended 126m (see below)
|
|
/dev/hda3 linux 126m development root partition
|
|
/dev/hda4 linux 6+gig raid1-1
|
|
----------------------hda2------------------------------
|
|
* /dev/hda5 linux 26m test raid1-1
|
|
* /dev/hda6 linux swap 100m
|
|
========================================================
|
|
|
|
/dev/hdc1 is simply an exact copy of hda1 so the
|
|
partion can be made active if hda fails
|
|
* /dev/hdc2 extended 126m (see below)
|
|
/dev/hdc3 linux 126m development /usr/src
|
|
/dev/hdc4 linux 6+gig raid1-2
|
|
----------------------hdc2------------------------------
|
|
* /dev/hdc5 linux 26m test raid1-2
|
|
* /dev/hdc6 linux swap 100m
|
|
</PRE>
|
|
|
|
The sdx2 and hdx3 partitions were switched to 'swap' after developing
|
|
this utility. I could have done it on another machine, however,
|
|
the libraries and kernels are all about a year or more out of date
|
|
on my other linux boxes and I preferred to build it on the target machine.
|
|
<P>The partitioning scheme was chosen so that in the event that
|
|
any one of the drives fails catastrophically, the system will
|
|
continue to run and be bootable with minimum effort and NO data loss.
|
|
<UL>
|
|
<LI> If any single hard drive fails, the boot will abort, and
|
|
the rescue system will run. Examination of the screen
|
|
message or /dos<I>x</I>/raidboot/raidstat.ro will tell the operator
|
|
the status of the failed array.</LI>
|
|
<LI> If sda1 (raid5) or hda1 (raid1) fails, the dos backup boot partition
|
|
must be made 'active' and the bios must recognize the new partition
|
|
as the boot device or it must be physically be moved to the <I>x</I>da position.
|
|
Alternatively, the system could be booted from a floppy disk using
|
|
the initrd image on the remaining backup boot drive.
|
|
The raid system can then be made active again by issuing:
|
|
<PRE>
|
|
"/sbin/mkraid /etc/raid<it/x/.conf -f --only-superblock"
|
|
</PRE>
|
|
|
|
to rebuild the remaining superblock(s).
|
|
</LI>
|
|
<LI> Once this is done, then
|
|
|
|
<PRE>
|
|
mdadd -ar
|
|
</PRE>
|
|
|
|
</LI>
|
|
<LI> Examine the status of the array to verify that everything is OK
|
|
then replace the good array reference with the current status
|
|
until the failed disk can be repaired or replaced.
|
|
|
|
<PRE>
|
|
cat /proc/mdstat | grep md0 > /dosx/raidboot/raidgood.ref
|
|
|
|
shutdown -r now
|
|
</PRE>
|
|
|
|
to do a clean reboot, and the system is up again.</LI>
|
|
</UL>
|
|
<HR>
|
|
<A HREF="Root-RAID-HOWTO-6.html">Next</A>
|
|
<A HREF="Root-RAID-HOWTO-4.html">Previous</A>
|
|
<A HREF="Root-RAID-HOWTO.html#toc5">Contents</A>
|
|
</BODY>
|
|
</HTML>
|