June 2015
M T W T F S S
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891011121314
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Categories

June 2015
M T W T F S S
1234567
891011121314
15161718192021
22232425262728
2930  

Boot Into Single User Mode (Reset Root Password)

To reset the root password of your server, you will need to boot into single user mode.

Access the Manage section of your server in the customer portal and follow these steps. The option depends on the bootloader version on the machine:

CentOS 6 Click [View Console] to access the console and click the send […]

The WebLogic Admin Server 11g just hangs upon startup

Problem:

Due to our disk space having filled up, I shutdown the Oracle WebLogic AdminServer 11g (11.1.1.3), cleared some logs, and restarted it.

However, when I start it up, it just stops at the entry below. No movement in the log whatsoever, and nothing is happening on the server.

oracle@oradev:/u01/app/oracle/middleware/user_projects/domains/soa_domain/bin> ./startWebLogic.sh ***************************************************** ** Setting up […]

Add date to bash history

Need to add date to bash history, knowing when some commands were fired.

Before the change:

root@host# history 1 ifconfig 2 ifup eth0 3 ifconfig 4 shutdown -r now

root@host# history 1 ifconfig 2 ifup eth0 3 ifconfig 4 shutdown -r now

Now, make appripriate changes in your bash profile:

echo ‘export HISTTIMEFORMAT=”%d/%m/%y %T “‘ […]

Changing default IO scheduler linux

Change default Linux IO scheduler to optimize IOs (very important if server is VM)

Check existing (active) io scheduler (elevator):

[root@server ~]# cat /sys/block/sda/queue/scheduler noop anticipatory deadline [cfq] # cfq active

[root@server ~]# cat /sys/block/sda/queue/scheduler noop anticipatory deadline [cfq] # cfq active

Change it on the fly

[root@server ~]# echo noop > /sys/block/sda/queue/scheduler

[root@server ~]# […]

VSPHERE 6 and VSAN

[gview file=”http://rmohan.com/wp-content/uploads/2015/06/vSphere-6.pptx”]

 

[gview file=”http://rmohan.com/wp-content/uploads/2015/06/Deck_VSAN_Hee-Teck.pdf”]

Tweak EXT4 mount options for performance

Need to change default EXT4 mount options to tweek performance

DEFAULT EXT4 mount options (Centos 6.3):

Shell [root@server ~]# cat /etc/fstab<br /> dev/sda1 / ext4 defaults 0 1 1 2 [root@server ~]# cat /etc/fstab dev/sda1 / ext4 defaults 0 1

… meaning …

Shell [root@server ~]# cat /proc/mounts | grep ext4<br /> /dev/sda1 / […]

Converting Your Keypair File

Purpose

The keypair you create will be in the .pem format. If you plan on using PuTTy to SSH to a Linux instance from a Windows computer you will need to convert that keypair file to the .ppk format. This article will show you those steps.

Notes

Your original private key pair file (.pem) is […]