Thursday, July 02, 2009

A “Multivendor Post” to help our mutual iSCSI customers using VMware

Very nice article explaining iSCSI in ESX environment
http://virtualgeek.typepad.com/virtual_geek/2009/01/a-multivendor-post-to-help-our-mutual-iscsi-customers-using-vmware.html

Platespin Recon 3.6 - bugs and issues

Platespin Recon 3.6 have big issues with hardware inventory of some servers. It can hang your server during CPU model checking!!! Platespin released hotfix for that. But that's not all. When you use database PostgreSQL 8.3 which is bundled with Recon it has significant performance issues. I was waiting for some reports several hours!!! I have troubleshooted and realized that there is some problem with SQL communication between Plaspin Recon application server and PostgreSQL. You can find error messages in PostgreSQL log file. It says something about abnormal client termination. If you use MS SQL Server it works like a sharm.

MS Windows Virtual Memory Management on consolidated virtual workloads

When you virtualize lot of MS Window workloads you can observe lot of "Memory Pages/s" from virtual machines to physical disk subsystem (system swaping inactive memory pages to hard drive) . If you haven't enough IO performance in your storage your virtual machines becomes slow. For virtualization is normaly used SAN environment. Don't forget design capacity and performance on your storage for page files. If you want to tune your MS Windows and optimize page file IOs to your storage try disable (if you have enough RAM) or optimize Windows Page File.

Articles about this topic:
http://www.techarp.com/showarticle.aspx?artno=143
http://www.petri.co.il/pagefile_optimization.htm
http://www.instantfundas.com/2008/07/disable-windows-page-file-save-your.html
http://www.windowsdevcenter.com/pub/a/windows/2004/04/27/pagefile.html
http://smallvoid.com/article/windows-page-file.html

Tuesday, June 23, 2009

PERL Getopt and GetOptions

When you code unix program first of all you need to get user options. Two Perl modules (Getopt and Getoptions::Long) work to extract program flags and arguments much like Getopt and Getopts do for shell programming. The Perl modules, especially GetOptions::Long, are much more powerful and flexible.

See full article at http://aplawrence.com/Unix/perlgetopts.html

Ultimate Deployment Appliance

Unattended OS installations (Windows, Linux, ESX, Solaris) over the network set-up in minutes! Look at http://www.ultimatedeployment.org/

Thursday, May 14, 2009

How to shutdown windows from linux

If you have samba you can use "net rpc SHUTDOWN -C "some comment here" -f -I x.x.x.x -U user_name%password"

Saturday, May 09, 2009

How to copy (backup) files from ESX3i?

You can use RCLI and vifs command. More info at
http://www.vm-help.com/esx/esx3i/esx_3i_rcli/vifs.php

Examples:
List files in datastore directory:
vifs --server 192.168.4.4 --username root --password ***** --dir "[Datastore1]/win2k3"

Download file from ESX3i Datastore:
vifs --server 192.168.4.4 --username root --dc ha-datacenter --password ***** --get "[Datastore1] /win2k3/win2k3-flat.vmdk" my-clone.vmdk

Notes:
File write speed around 1MBps only

Saturday, March 14, 2009

On demand VNC server with GDM

Each user can login (via ssh) to *nix server and start vncserver. Then he can login to X11 desktop via VNC viewer with defined vnc password. But it's far far away from nice solution. Much better solution is to setup vncserver as xinetd service.

First of all you have to define new service in particular port. Add line bellow into /etc/services
vnc1024         5901/tcp                        # VNC & GDM
now create service description for xinetd. Go to directory /etc/xinetd.d
cd /etc/xinetd.d
and create file vnc1024
service vnc1024
{
disable = no
socket_type = stream
protocol = tcp
wait = no
user = nobody
server = /usr/bin/Xvnc
server_args = -inetd -query localhost -geometry 1024x800 -depth 16 -once -fp unix/:7100 -securitytypes=none
}
Move to runlevel 3
init 3
Restart xinetd
/etc/init.d/xinetd
Move back to runlevel 5
init 5
And that's it. Now try connect via VNCviewer to port 6901

Wednesday, February 18, 2009

DR & BC of virtualized datacenters

Virtualization significantly helps to implement Disaster Recovery and Business Continuity scenarios. But some one can think that he can install VMware SRM software and DR&BC solution is ready. It's common mistake. VMware SRM is just arround 5% of DR&BC solution. You have to concider right technology and proper proceses with respect of your particular environment. Right technology means storage replications, network high availabaility across datacenters, automation, etc.

Nice article about VMware implementation conciderations is at http://searchvmware.techtarget.com/tip/0,289483,sid179_gci1347066_mem1,00.html?track=NL-915&ad=689280&asrc=EM_NLN_5870851

Tuesday, February 17, 2009

Configuration Point-to-Point OpenVPN link

I like OpenVPN because it's simple and it does what you need - VPN.

Let's assume that we have two un*x like servers with OpenVPN software and regular OS user openvpn in group openvpn. One server has IP address 192.168.4.10 and second 192.168.4.100.

In server 192.168.4.10 use following configuration file (openvpn.conf):
remote 192.168.4.100
ifconfig 10.0.0.1 10.0.0.2
dev tun0
port 5001
proto udp
secret /usr/local/etc/openvpn/secret.key
ping 10
comp-lzo
verb 5
mute 10
user openvpn
group openvpn

In server 192.168.4.100 use following configuration file (openvpn.conf):
remote 192.168.4.10
ifconfig 10.0.0.2 10.0.0.1
dev tun0
port 5001
proto udp
secret /usr/local/etc/openvpn/secret.key
ping 10
comp-lzo
verb 5
mute 10
user openvpn
group openvpn

In one of this two servers create secret.key by issuing following command:
openvpn --genkey --secret /usr/local/etc/openvpn/secret.key

Finaly:
Somehow (for example scp) copy secret key to second server into correct location and run openvpn daemons on both servers. On servers new network interface appears (tap) with IP addresses (10.0.0.1 and 10.0.0.2) and you can ping these 10.0.0.1-2 IP addresses over secure VPN link.

Here we go.