Scanning for SCSI new devices dynamically on CentOS

sg3_utils is a package of utilities for sending SCSI commands. For this particular blog entry, we will focus on the scanning for new SCSI new scsi dynamically without booting. Do

# yum install sg3_utils

==============================================================================
 Package                          Arch                     Version                       Repository              Size
==============================================================================
Installing:
 sg3_utils                        x86_64                   1.25-5.el5                    base                   501 k
Installing for dependencies:
 sg3_utils-libs                   x86_64                   1.25-5.el5                    base                    51 k

Transaction Summary
==============================================================================
Install      2 Package(s)
Update       0 Package(s)
Remove       0 Package(s)

Total download size: 553 k
Is this ok [y/N]:

To scan the SCSI-Bus. use the command

# rescan-scsi-bus.sh

Host adapter 0 (aacraid) found.
Host adapter 1 (ata_piix) found.
Host adapter 2 (ata_piix) found.
Host adapter 3 (qla2xxx) found.
Host adapter 4 (qla2xxx) found.
Scanning SCSI subsystem for new devices
Scanning host 0 for  SCSI target IDs  0 1 2 3 4 5 6 7, all LUNs
Scanning for device 0 0 0 0 ...
OLD: Host: scsi0 Channel: 00 Id: 00 Lun: 00
      Vendor: ServeRA  Model: A                Rev: V1.0 
      Type:   Direct-Access                    ANSI SCSI revision: 02
Scanning for device 0 1 0 0 ...
OLD: Host: scsi0 Channel: 01 Id: 00 Lun: 00
      Vendor: IBM-ESXS Model: VPA146C3-ETS10 N Rev: A650
      Type:   Direct-Access                    ANSI SCSI revision: 05
.....
.....
.....
0 new device(s) found.
0 device(s) removed.

Green Revolution cooling announces full factory warranty from supermicro

According to the website announcement,  

Super Micro Computer, Inc. (Supermicro®) is now providing full warranty coverage for servers installed in the CarnotJet™ submersion cooling system. The assurance is a momentous step forward for Green Revolution Cooling and confirms the long-term reliability of servers installed in the CarnotJet™ system.

The warranty will cover motherboards, backplanes, add-on cards, power supplies, and processors for parts and labor. DIMM modules and SSDs are also covered in the warranty, as are all other manufacturer defects discovered during server operation in the CarnotJet™ system.

Lastly, Supermicro® is also offering a line of products available submersion-ready direct from the factory. With Supermicro® servers turn-key and fully guaranteed, it has never been easier to outfit your data center with submersion cooling from Green Revolution Cooling.

For more information of the announcement, do read Green Revolution Cooling Announces Full Factory Warranty from Supermicro®

Restoring a snapshot from Netapp from a newbie

I am a newbie to NetApp Storage solution. Creation and restoring Snapshot in Netapp could not be easier.

Basically, NetApp provides a very easy-to-recognise snapshot features. The Snapshot schedules are

1.  Weekly Snapshot copies are taken at 24:00 on Sunday, creating Snapshot copies called weekly.n, where n is an integer (weekly.0, weekly.1, weekly.2, and so on).
2. Nightly Snapshot copies are taken at 24:00 Monday through Saturday, creating Snapshot copies called nightly.n, where n is an integer (nightly.0, nightly.1, and so on).
3. Four hourly Snapshot copies are taken at 8 a.m., noon, 4 p.m., and 8 p.m., unless specified otherwise using the hourly Snapshot copy schedule in this window, creating Snapshot copies called hourly.n, where n is an integer (hourly.0, hourly.1, hourly.2, and so on).

You can easily select your snapshot schedule with some simple select and click.

If you make your snapshot directory visible, The snapshot content can be easily be seen from .shapshot directory of the NetApp volume.Restoration is very easy then. Assuming the NetApp volume is mounted as /home and you wish to recover nightly.0

# cp -avp /home/.snapshot/nightly.0/home/mysite/recover_my_folder /home/mysite/

that's it! I was quite amazed at the ease of the restoration of the lost folder.

Java Zero Day Flaw Under Attack

Taken from  Experts Suggest Disabling Java after Zero-Day Flaw Discovery

Security firm FireEye released information yesterday on a Java flaw that has been seen in targeted attacks in the wild, and has been tested to work on most major Web browsers for both Mac and PC.

According to researchers, all versions of Java (including the Java 7 Update 6) are susceptible to attack, and can lead to the installation of malware on a system.

The hole is due to an issue in how the "setSecurityManager()" function in Java is called. Attackers can exploit this issue and set its own privileges on a targeted system, allowing the downloading and execution of malicious software. 

Read on for more information.........

Proposed workaround:

1. Read US-CERT Vulnerability Note VU#636312

Other Information:

1.  Warning: Java Zero Day Flaw Under Attack

Persistent VNC Session for users for CentOS

If you are intending to setup a persistent VNC Session for selected users, you can edit the global settings at /etc/sysconfig/vncservers.

# vim /etc/sysconfig/vncservers 

# The VNCSERVERS variable is a list of display:user pairs.
#
# Uncomment the lines below to start a VNC server on display :2
# as my 'myusername' (adjust this to your own).  You will also
# need to set a VNC password; run 'man vncpasswd' to see how
# to do that.
#
# DO NOT RUN THIS SERVICE if your local area network is
# untrusted!  For a secure way of using VNC, see this URL:
# http://kbase.redhat.com/faq/docs/DOC-7028

# Use "-nolisten tcp" to prevent X connections to your VNC server via TCP.

# Use "-localhost" to prevent remote VNC clients connecting except when
# doing so through a secure tunnel.  See the "-via" option in the
# `man vncviewer' manual page.

# VNCSERVERS="2:myusername"
# VNCSERVERARGS[2]="-geometry 800x600 -nolisten tcp -localhost"

VNCSERVERS="2:user1"
VNCSERVERS="3:user2"
VNCSERVERARGS[2]="-geometry 1280x800 -depth 16"
VNCSERVERARGS[3]="-geometry 1024x768"

Once done, you just restart the vncserver services

# service vncserver restart