ocfs2

install ocfs2 and latest version of ocfs2-tools
identify the right ocfs2 version, echo ocfs2-`uname -r`
mkdir /etc/ocfs2
cat /etc/ocfs2/cluster.conf

[root@camkh1ddevdb001 ~]# cat /etc/ocfs2/cluster.conf
cluster:
        node_count = 2
        name = bkpcvrd

node:
        ip_port = 7777
        ip_address = 10.32.37.68
        number = 0
        name = camkh1ddevdb001
        cluster = bkpcvrd

node:
        ip_port = 7777
        ip_address = 10.32.37.69
        number = 1
        name = camkh1ddevdb002
        cluster = bkpcvrd
# service o2cb configure
# mkfs.ocfs2 -L anylabel /dev/mapper/blabla
mount like normal

multipath

# stmsboot -e | -d
# mpathadm test lu
# ls /kernel/drv/s*.conf
# ls /kernel/drv/scsi*conf

scan disks

# devfsadm
# cfgadm -al
# luxadm -e port
# luxadm -forcelip port
# luxadm -e dump_map port  

Xen: Connecting and Disconnecting Device

# xm block-list domain
Vdev  BE handle state evt-ch ring-ref BE-path
768    0    0     1      -1     -1    /local/domain/0/backend/vbd/20/768
5632   0    0     1      -1     -1    /local/domain/0/backend/vbd/20/5632
# xenstore-read /local/domain/0/backend/vbd/20/5632/params
/mnt/w7.iso
# xm block-detach domain 5632 -f
# xm block-attach domain file:/path/to/device /dev/hdc r

Get WWN Redhat 6

# systool -v -c fc_host | grep port_name

requires sysfsutils pkg


update:
# /lib/udev/scsi_id --page=0x83 --whitelisted --device=/dev/sdw

modprobe: FATAL: Error inserting bonding

modprobe: FATAL: Error inserting bonding  (/lib/modules/2.6.18-194.17.1.el5/kernel/drivers/net/bonding/bonding.ko):  Unknown symbol in module, or unknown parameter 
Resolution
Within the modprobe configuration file : /etc/modprobe.conf
Change the line:
install ipv6 /bin/false
to
options ipv6 disable=1
to load the bonding module with success.

One Whole VG for an LV

#!/pathtoshell
VG=$1
LV=$2
MOUNTPOINT=$3
MPATH=0
for i in `ls /sys/class/scsi_host/host*/scan`
  do echo "- - -" > $i; done
sleep 5
multipath -ll
echo -n "enter mpath:"
read MPATH
pvcreate /dev/mapper/${MPATH}
vgcreate -s 32 $VG /dev/mapper/${MPATH}
lvcreate -l 100%VG -n $LV $VG
mkfs.ext4 /dev/mapper/${VG}-${LV}
if [ ! -d $MOUNTPOINT ]
  then mkdir $MOUNTPOINT; fi
mount /dev/mapper/${VG}-${LV} $MOUNTPOINT
echo -e \
  "/dev/mapper/${VG}-${LV}" "\t" \
  "${MOUNTPOINT}" "\t" \
  "ext4" "\t" "defaults" "\t" "1 2" \
  >> /etc/fstab

CleanUp Multipath, Remove Failed Faulty Device

# for i in /sys/class/scsi_host/host*/scan
> do echo "- - -" > $i
> done
# DEV=`multipath -ll | grep failed | awk '{print $3}'`
# for i in $DEV
> do echo 1 > /sys/block/${i}/device/delete
done

Rebuild Yum Database

# rm -f /var/lib/rpm/__db*
# rpm --rebuilddb
# yum clean all
# yum update

Create Empty Disk Image

# dd bs=8192 count=10000 if=/dev/zero of=/tmp/disk.iso
# mkfs.msdos /tmp/disk.iso

Redhat enable multipath

# yum install sysfsutils
# yum install device-mapper-multipath
# mpathconf --enable --with_multipathd y

System log filled by snmpd messages

[root@myxen ~]# tail -5 /var/log/messages
Aug 15 03:19:30 myxen snmpd[10298]: Received SNMP packet(s) from UDP: [127.0.0.1]:42695
Aug 15 03:19:45 myxen snmpd[10298]: Received SNMP packet(s) from UDP: [127.0.0.1]:40647
Aug 15 03:19:47 myxen snmpd[10298]: Received SNMP packet(s) from UDP: [127.0.0.1]:56802
Aug 15 03:20:02 myxen snmpd[10298]: Received SNMP packet(s) from UDP: [127.0.0.1]:55952
Aug 15 03:20:02 myxen snmpd[10298]: Received SNMP packet(s) from UDP: [127.0.0.1]:33076

Solution:
[root@myxen ~]# cat /etc/sysconfig/snmpd.options
# snmpd command line options
# OPTIONS="-Lsd -Lf /dev/null -p /var/run/snmpd.pid -a"
OPTIONS="-LS 4 d -p /var/run/snmpd.pid -a"


Logging Options:

For -LF and -LS the priority specification comes before the file or facility token. The priorities recognised are:

0 or ! for LOG_EMERG, 
1 or a for LOG_ALERT, 
2 or c for LOG_CRIT, 
3 or e for LOG_ERR, 
4 or w for LOG_WARNING, 
5 or n for LOG_NOTICE, 
6 or i for LOG_INFO, and 
7 or d for LOG_DEBUG.

-p FILE
Save the process ID of the daemon in FILE.

-a
Log the source addresses of incoming requests.

Enable SSH to HP ILO

# grep ilo /etc/inittab
ilo:2345:respawn:/sbin/agetty ttyS1 115200 vt100
# grep ttyS1 /etc/securetty
ttyS1
# kill -HUP 1