Saturday, March 7, 2009

Fork Bomb for isolation measurement with virtualization

I am determining if fork bomb is a good way to determine the isolation provided by a virtualization mechanism. I am planning to evaluate the impact of fork bombing an OS level virtualization mechanism like OpenVZ and a para-level mechanism like Xen. Some tests by random users have shown that Xen can withstand such an attack. The question here is ... can OpenVZ do the same?

More on fork bombing here.
Baseline fork bomb in shell:
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Friday, March 6, 2009

Difference between SNAT and Masquerade On NAT

MASQUERADE is most often used in the same settings as SNAT. Using the MASQUERADE target results in determining the IP dynamically instead of using the static IP as provided with SNAT. Though the computation in this process increases MASQUERADE provides correct operation in real world situations where public IPs are often assigned by service providers using DHCP and can change over time.

Thursday, March 5, 2009

The 301 redirect

Looking to redirect to your new web address from your old without hurting search engine ratings? 301 redirect is your friend. This can be easily established by creating a .htaccess file and placing it in the web directory (E.g. public_html)
on that machine.

The .htaccess file should have some content like:
redirect 301 /~old_login/old_page.html http://www.new-site.com/new_page.html


Just did this for my old page and works like a charm!
Good luck.

Do not forget to chmod the .htaccess file to 755 before you try this out :)