High performance and reliable storage tends to be expensive.
High performance and cheap tends to require a lot of maintenance.
Reliable and cheap tends to be really really slow.
as stated by Gonzo.

Can’t find documentation on how to setup RHEL 5.5 GFS cluster. Woof!
August 3rd, 2010, the good guys from DELL: how to install and configure Red Hat Cluster Suite and Global File System on your Dell|Red Hat HA Cluster system using Conga and CLI Tools on a M1000e:
http://linux.dell.com/wiki/index.php/Products/HA/DellRedHatHALinuxCluster/Cluster
August 20th, 2010, the “Samba Cluster with GFS 2, Centos 5, iSCSI and Openfiler” (aka “Samba Cluster with GFS, RHEL 5, iSCSI and Openfiler”) by Roggy, a perfect live training session published on vimeo:
http://roggyblog.blogspot.com/2010/03/samba-cluster-with-gfs-2-centos-5-iscsi.html

Hard drive failure (HD0) simulation under Fedora 13 with RAID1 software mirror (on a Michael Dell GX260, 2x20G system disks, RAID1 software mirror):

Power off GX260, remove HD0, swap HD1 instead HD0, mount your new hard disk as HD1 (another WD200, 20G, manufacture date: July 4th, 2002, 8 years old ~ almost like a bottle of wine), power up system:

[root@~]# fdisk -l /dev/sda
Disk /dev/sda: 20.0 GB, 20000000000 bytes
255 heads, 63 sectors/track, 2431 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0006aa5b
Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 204800 fd Linux raid autodetect
/dev/sda2 26 537 4106240 fd Linux raid autodetect
/dev/sda3 537 666 1034240 fd Linux raid autodetect
/dev/sda4 666 2432 14184448 5 Extended
/dev/sda5 666 1177 4106240 fd Linux raid autodetect
/dev/sda6 1178 1689 4106240 fd Linux raid autodetect
/dev/sda7 1689 1753 512000 fd Linux raid autodetect
/dev/sda8 1753 2432 5455872 fd Linux raid autodetect

[root@~]# fdisk -l /dev/sdb
Disk /dev/sdb: 20.0 GB, 20000000000 bytes
255 heads, 63 sectors/track, 2431 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x2b2b2b2b
Disk /dev/sdb doesn’t contain a valid partition table

[root@~]# sfdisk -d /dev/sda | sfdisk -f /dev/sdb
Warning: extended partition does not start at a cylinder boundary.
DOS and Linux will interpret the contents differently.
Checking that no-one is using this disk right now …
OK
Disk /dev/sdb: 2431 cylinders, 255 heads, 63 sectors/track
sfdisk: ERROR: sector 0 does not have an msdos signature
/dev/sdb: unrecognized partition table type
Old situation:
No partitions found
New situation:
Units = sectors of 512 bytes, counting from 0
Device Boot Start End #sectors Id System
/dev/sdb1 * 2048 411647 409600 fd Linux raid autodetect
/dev/sdb2 411648 8624127 8212480 fd Linux raid autodetect
/dev/sdb3 8624128 10692607 2068480 fd Linux raid autodetect
/dev/sdb4 10692608 39061503 28368896 5 Extended
/dev/sdb5 10694656 18907135 8212480 fd Linux raid autodetect
/dev/sdb6 18909184 27121663 8212480 fd Linux raid autodetect
/dev/sdb7 27123712 28147711 1024000 fd Linux raid autodetect
/dev/sdb8 28149760 39061503 10911744 fd Linux raid autodetect
Warning: partition 1 does not end at a cylinder boundary
Successfully wrote the new partition table
Re-reading the partition table …
If you created or changed a DOS partition, /dev/foo7, say, then use dd(1)
to zero the first 512 bytes: dd if=/dev/zero of=/dev/foo7 bs=512 count=1
(See fdisk(8).)

[root@~]# tail -100 /var/log/messages
Jul 25 13:27:30 kernel: sdb: unknown partition table
Jul 25 13:27:31 kernel: sdb: sdb1 sdb2 sdb3 sdb4 < sdb5 sdb6 sdb7 sdb8 >

[root@~]# fdisk -l /dev/sdb
Disk /dev/sdb: 20.0 GB, 20000000000 bytes
255 heads, 63 sectors/track, 2431 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x2b2b2b2b
Device Boot Start End Blocks Id System
/dev/sdb1 * 1 26 204800 fd Linux raid autodetect
/dev/sdb2 26 537 4106240 fd Linux raid autodetect
/dev/sdb3 537 666 1034240 fd Linux raid autodetect
/dev/sdb4 666 2432 14184448 5 Extended
/dev/sdb5 666 1177 4106240 fd Linux raid autodetect
/dev/sdb6 1178 1689 4106240 fd Linux raid autodetect
/dev/sdb7 1689 1753 512000 fd Linux raid autodetect
/dev/sdb8 1753 2432 5455872 fd Linux raid autodetect

[root@~]# cat /proc/mdstat
Personalities : [raid1]
md6 : active raid1 sda8[1]
5454840 blocks super 1.1 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk
md5 : active raid1 sda7[2]
511992 blocks super 1.1 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk
md4 : active raid1 sda6[1]
4105208 blocks super 1.1 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk
md3 : active raid1 sda5[1]
4105208 blocks super 1.1 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk
md2 : active raid1 sda3[1]
1034232 blocks super 1.1 [2/1] [_U]
md1 : active raid1 sda2[1]
4105208 blocks super 1.1 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk
md0 : active raid1 sda1[1]
204788 blocks super 1.0 [2/1] [_U]

[root@~]# mdadm –detail /dev/md0
/dev/md0:
Version : 1.0
Creation Time : Tue Jul 20 17:23:15 2010
Raid Level : raid1
Array Size : 204788 (200.02 MiB 209.70 MB)
Used Dev Size : 204788 (200.02 MiB 209.70 MB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Sun Jul 25 13:24:49 2010
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : localhost.localdomain:0
UUID : 287d4602:92e45868:b43b0181:dc86d27a
Events : 164
Number Major Minor RaidDevice State
0 0 0 0 removed
1 8 1 1 active sync /dev/sda1

[root@~]# mdadm –add /dev/md0 /dev/sdb1
mdadm: added /dev/sdb1

[root@~]# mdadm –detail /dev/md0
/dev/md0:
Version : 1.0
Creation Time : Tue Jul 20 17:23:15 2010
Raid Level : raid1
Array Size : 204788 (200.02 MiB 209.70 MB)
Used Dev Size : 204788 (200.02 MiB 209.70 MB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Sun Jul 25 13:31:07 2010
State : clean, degraded, recovering
Active Devices : 1
Working Devices : 2
Failed Devices : 0
Spare Devices : 1
Rebuild Status : 30% complete
Name : localhost.localdomain:0
UUID : 287d4602:92e45868:b43b0181:dc86d27a
Events : 180
Number Major Minor RaidDevice State
2 8 17 0 spare rebuilding /dev/sdb1
1 8 1 1 active sync /dev/sda1

[root@~]# mdadm –detail /dev/md0
/dev/md0:
Version : 1.0
Creation Time : Tue Jul 20 17:23:15 2010
Raid Level : raid1
Array Size : 204788 (200.02 MiB 209.70 MB)
Used Dev Size : 204788 (200.02 MiB 209.70 MB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Sun Jul 25 13:31:14 2010
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Name : localhost.localdomain:0
UUID : 287d4602:92e45868:b43b0181:dc86d27a
Events : 208
Number   Major   Minor   RaidDevice State
2       8       17        0      active sync   /dev/sdb1
1       8        1        1      active sync   /dev/sda1

[root@~]# mdadm –detail /dev/md6
/dev/md6:
Version : 1.1
Creation Time : Tue Jul 20 17:23:53 2010
Raid Level : raid1
Array Size : 5454840 (5.20 GiB 5.59 GB)
Used Dev Size : 5454840 (5.20 GiB 5.59 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Sun Jul 25 13:24:49 2010
State : active, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : localhost.localdomain:6
UUID : ce89732a:5e6407fd:871f6954:8b61ecc6
Events : 206
Number Major Minor RaidDevice State
0 0 0 0 removed
1 8 8 1 active sync /dev/sda8

[root@~]# mdadm –add /dev/md6 /dev/sdb8
mdadm: added /dev/sdb8

[root@~]# mdadm –detail /dev/md6
/dev/md6:
Version : 1.1
Creation Time : Tue Jul 20 17:23:53 2010
Raid Level : raid1
Array Size : 5454840 (5.20 GiB 5.59 GB)
Used Dev Size : 5454840 (5.20 GiB 5.59 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Sun Jul 25 13:56:42 2010
State : active, degraded, recovering
Active Devices : 1
Working Devices : 2
Failed Devices : 0
Spare Devices : 1
Rebuild Status : 1% complete
Name : localhost.localdomain:6
UUID : ce89732a:5e6407fd:871f6954:8b61ecc6
Events : 212
Number Major Minor RaidDevice State
2 8 24 0 spare rebuilding /dev/sdb8
1 8 8 1 active sync /dev/sda8

[root@~]# mdadm –detail /dev/md6
/dev/md6:
Version : 1.1
Creation Time : Tue Jul 20 17:23:53 2010
Raid Level : raid1
Array Size : 5454840 (5.20 GiB 5.59 GB)
Used Dev Size : 5454840 (5.20 GiB 5.59 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Sun Jul 25 13:56:47 2010
State : active, degraded, recovering
Active Devices : 1
Working Devices : 2
Failed Devices : 0
Spare Devices : 1
Rebuild Status : 4% complete
Name : localhost.localdomain:6
UUID : ce89732a:5e6407fd:871f6954:8b61ecc6
Events : 216
Number Major Minor RaidDevice State
2 8 24 0 spare rebuilding /dev/sdb8
1 8 8 1 active sync /dev/sda8

[root@~]# cat /proc/mdstat
Personalities : [raid1]
md6 : active raid1 sdb8[2] sda8[1]
5454840 blocks super 1.1 [2/1] [_U]
[=====>...............] recovery = 25.7% (1405440/5454840) finish=2.2min speed=30092K/sec
bitmap: 1/1 pages [4KB], 65536KB chunk
md5 : active raid1 sdb7[3] sda7[2]
511992 blocks super 1.1 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md4 : active raid1 sda6[1]
4105208 blocks super 1.1 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk
md3 : active raid1 sda5[1]
4105208 blocks super 1.1 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk
md2 : active raid1 sda3[1]
1034232 blocks super 1.1 [2/1] [_U]
md1 : active raid1 sda2[1]
4105208 blocks super 1.1 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk
md0 : active raid1 sdb1[2] sda1[1]
204788 blocks super 1.0 [2/2] [UU]
unused devices:

[root@~]# cat /proc/mdstat
Personalities : [raid1]
md6 : active raid1 sdb8[2] sda8[1]
5454840 blocks super 1.1 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md5 : active raid1 sdb7[3] sda7[2]
511992 blocks super 1.1 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md4 : active raid1 sda6[1]
4105208 blocks super 1.1 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk
md3 : active raid1 sda5[1]
4105208 blocks super 1.1 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk
md2 : active raid1 sda3[1]
1034232 blocks super 1.1 [2/1] [_U]
md1 : active raid1 sda2[1]
4105208 blocks super 1.1 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk
md0 : active raid1 sdb1[2] sda1[1]
204788 blocks super 1.0 [2/2] [UU]
unused devices:

[root@~]# mdadm –add /dev/md2 /dev/sdb3
mdadm: added /dev/sdb3

[root@~]# mdadm –detail /dev/md2
/dev/md2:
Version : 1.1
Creation Time : Tue Jul 20 17:23:27 2010
Raid Level : raid1
Array Size : 1034232 (1010.16 MiB 1059.05 MB)
Used Dev Size : 1034232 (1010.16 MiB 1059.05 MB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Sun Jul 25 14:08:38 2010
State : clean, degraded
Active Devices : 1
Working Devices : 2
Failed Devices : 0
Spare Devices : 1
Name : localhost.localdomain:2
UUID : 8775b7b9:8a08626c:15abe820:0723e0a5
Events : 198
Number Major Minor RaidDevice State
2 8 19 0 spare rebuilding /dev/sdb3
1 8 3 1 active sync /dev/sda3

[root@~]# cat /proc/mdstat
Personalities : [raid1]
md6 : active raid1 sdb8[2] sda8[1]
5454840 blocks super 1.1 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md5 : active raid1 sdb7[3] sda7[2]
511992 blocks super 1.1 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md4 : active raid1 sdb6[2] sda6[1]
4105208 blocks super 1.1 [2/1] [_U]
[============>........] recovery = 61.4% (2524672/4105208) finish=1.2min speed=20999K/sec
bitmap: 1/1 pages [4KB], 65536KB chunk
md3 : active raid1 sdb5[2] sda5[1]
4105208 blocks super 1.1 [2/1] [_U]
resync=DELAYED
bitmap: 1/1 pages [4KB], 65536KB chunk
md2 : active raid1 sdb3[2] sda3[1]
1034232 blocks super 1.1 [2/1] [_U]
resync=DELAYED
md1 : active raid1 sdb2[2] sda2[1]
4105208 blocks super 1.1 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md0 : active raid1 sdb1[2] sda1[1]
204788 blocks super 1.0 [2/2] [UU]
unused devices:

[root@~]#