service ntpd stop

 cp /usr/share/zoneinfo/Asia/Singapore /etc/localtime

 ntpdate

 service ntpd start 

more info: http://www.redhat.com/advice/tips/timezone.html

 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.

One solution is to remove the offending host key

ssh-keygen -f "/home/chris/.ssh/known_hosts" -R ip-address-of-the-host

..check that your my.cnf matches the ibdata files..

one solution was to move all ib* data and restart mysqld

 mkdir /srv/mysql/old
mv /srv/mysql/ib* /srv/mysql/old
service mysqld restart

virt-install --prompt

List virtual machine

virsh list

Stop virtual machine

virsh destroy <vm name>

Configure VM autostart

virsh autostart <vm name>

Unconfigure VM autostart

virsh autostart --disable <vm name>

To install using kickstart

virt-install --name=rhel03.localdomain -r 768 --disk path=/var/lib/libvirt/images/rhel03.localdomain.img,size=8 -l http://192.168.122.1/pub/inst -x "ks=http://192.168.122.1/pub/ks/rhel03.cfg"

To create VM snapshot

virsh save centos01 centos01.snap.$(date +%y%m%d)

To restore VM snapshot

virsh shutdown centos01
virsh restore centos01.snap

Clone vm

virt-clone --original centos01 --name centos02 --file /home/penoycentral/images/centos02.img

Troubleshooting KVM

Error when starting the VM snapshot

error restoring domain unable to read from monitor

To fix

virsh managedsave-remove domain-name

mysqladmin -u root password 'new-password'

Show databases

mysql> show databases;
mysql> use databasename;

Show tables

mysql> show tables;

Show columns

mysql> select column from tables;

Backup database

$mysqldump -u <username> -p <databasename> > backupdatabase.sql

Restore database

mysql -u <username> -p <database> < databasebackup.sql

http://www.amazon.com/RHCSA-Certification-Practice-Virtual-Machines/dp/007180160X/ref=sr_1_4?s=books&ie=UTF8&qid=1335154380&sr=1-4

It is found under:

/usr/lib/vmware/bin/vmware-netcfg

Will post some reviews next week (if again i have the time )

Initialize:

snapmirror initialize -S <source-qtree> <destination-qtree>
filer2> snapmirror initialize -S filer1:/vol/vol2/qtree-name filer2:/vol/vol0/qtree-name

Snapmirror status

> snapmirror status

Pause Snapmirror

>snapmirror quiesce <qtree>
filer2> snapmirror quiesce /vol/vol0/qtree-name

Resume Snapmirror

>snapmirror resume <destination-path>
filer2> snapmirror resume /vol/vol0/qtree-name

To break Snapmirror (for destination to be rw)

filer2> snapmirror quiesce /vol/vol0/qtree-name
filer2> snapmirror break /vol/vol0/qtree-name

Check qtree status

>qtree status

Remirror

filer2> snapmirror resync -S filer1:/vol/vol2/qtree-name filer2:/vol/vol0/qtree-name

http://www.sysadmintutorials.com/tutorials/netapp/netapp-snapmirror-setup/

tmpfs /dev/shm tmpfs size=4096m 0 0</blockquote>

After reboot, size still on 2G

[root@OEL1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_oel1-lv_root
16G 3.8G 11G 27% /
tmpfs 2.0G 0 2.0G 0% /dev/shm
/dev/sda1 485M 51M 409M 12% /boot

Looks like a bug on RHEL6

https://www.redhat.com/archives/rhelv6-list/2011-February/msg00081.html

[root@OEL1 ~]# mount -o remount /dev/shm
[root@OEL1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_oel1-lv_root
16G 3.8G 11G 27% /
tmpfs 4.0G 0 4.0G 0% /dev/shm
/dev/sda1 485M 51M 409M 12% /boot
[root@OEL1 ~]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 6.2 (Santiago)