Month: July 2012

3TB partition support in Linux

Make a GPT partition:

parted /dev/sda
mklabel gpt
unit TB
mkpart primary 0 -0

Format with 1% root reservation:

mkfs.ext4 -m1 /dev/sda1

Note: HP Array controller may require firmware update for 3TB disk support.

How to increase VM disk size without re-deploy the machine


[root@demo ~]# fdisk /dev/sda

-Create a primary partition-

[root@demo ~]# fdisk -l

Device Boot Start End Blocks Id System
/dev/sda1 * 1 64 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 64 1306 9972736 8e Linux LVM
/dev/sda3 1306 6527 41942367+ 83 Linux

[root@demo ~]# pvcreate /dev/sda3
[root@demo ~]# vgextend vg_demo /dev/sda3

[root@demo ~]# vgdisplay vg_demo | grep Free
Free PE / Size 10239 / 40.00 GiB

[root@demo ~]# lvextend -L+40.00G /dev/vg_demo/lv_root

[root@demo ~]# resize2fs /dev/vg_demo/lv_root

Note: I wouldn’t do this for any production system as it looks pretty inefficient way to extend volume size.

L2L VPN with ASA – Connection established but no packet coming from one side


1. Connection established.

2. 0 en/decapsulated packet from one side.


Seems like ASA pickup Dynamic VPN profile if it has higher priority than L2L.

Resolved after change dynamic profile priority.


Fix Hadoop leap second bug without rebooting


Applied our hadoop node having CPU usage issue. (CentOS)

service ntpd stop
date `date +”%m%d%H%M%C%y.%S”`
service ntpd start

Works like a charm!