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Archive for October, 2011

why BST/DST(British Summer Time, Daylight Saving Time) achives the goal of saving energy

October 31st, 2011 No comments

Greenwich Mean Time

Tonight(30th October 2011), we’ll welcome the GMT(Greenwich Mean Time) and hug away BST(British Summer Time, Daylight Saving Time) at 01:59:59 30th October 2011.

Why BST/DST(British Summer Time, Daylight Saving Time) achives the goal of saving energy? As you may think I still am going to work 8 hours a day and 365 days a year(may be too much? :D). OK, here’s what I think.

As we all can experience, the sun arise earlier in Summer than in Autumn. So when you wake up in the morning, you’ll do not need turn on the light, that does save the energy. And another extreme example, one man sleeps all the day and play games all the night, and another man sleeps all the night and work all the day, which one do you think is more environmentally friendly? Actually, this was why Benjamin Franklin, the man on $100, suggest DST(Daylight Saving Time).

Benjamin Franklin

Benjamin Franklin

Categories: Life Tags:

List of build automation software

October 29th, 2011 No comments

Things like make/ant/hudson etc. See this url for details: http://en.wikipedia.org/wiki/List_of_build_automation_software

Categories: IT Architecture Tags:

vcs architecture overview

October 28th, 2011 No comments
vcs architecture overview

vcs architecture overview

Possible issue with latest version (6.8) of Oracle Explorer(vulnerability)

October 24th, 2011 No comments

I have been made aware of a potential issue with the latest version of explorer (6.8). The issue is caused because Explorer is calling a command (pcitool ) and that can cause a system to crash.
Check the version currently on your OS:
# cat /etc/opt/SUNWexplo/default/explorer|grep EXP_DEF_VERSION

EXP_DEF_VERSION=”6.8″

Alternatively, if you want get it in a script:

VER=$(nawk  -F= ‘/EXP_DEF_VERSION/ {print $NF}’ /etc/opt/SUNWexplo/default/explorer |sed ‘s/\”//g’)

There are a number of workarounds…
—————————————————————–
1) downgrade explorer to 6.7

2) comment the line 674 (‘get_cmd “/usr/sbin/pcitool -v” sysconfig/pcitool-v’) by adding ‘#’ to the beginning of it

3) make /usr/sbin/pcitool not executable on these systems (either remove it or change permissions)

PS:

For solaris explorer related concepts/download etc, please refer to http://blogs.oracle.com/PJ/entry/solaris_10_explorer_data_collection

relationship between dmx srdf bcv

October 24th, 2011 No comments

The R1 BCV is related to the R1 DEV the R1 is srdf’d to the R2. The R2 is related to the R2 BCV. There is no direct relationship between the R1dev and the R2 bcv.
The symdg’s as you know are contained in a local host based config database which group together devs you want to run commands on at the same time so you can fail them over a s a group or sync/split the bcv’s as a group without having to list all the devs.

DMX_SRDF_SAN_VCS

DMX_SRDF_SAN_VCS

R1BCV_R1DEV_R2BCV_R2DEV

R1BCV_R1DEV_R2BCV_R2DEV

Because you only talk to the local array you specify your DEV’s in your symdg as the ones that are local to you via symld. When symdgs are first created they are type R1 or R2 depending on if you’re going to add R1 or R2 devices. This will automatically update when you fail over. The devices you add to your symdg are always the ones that are on your local array. The rdf relationship does not need to be specified in the symdg it is inherent to the device as it is a 1-2-1 relationship so when you run a symrdf query it will find out the paired device from the array.
BCV’s are different because you can have more than one BCV attached to a device.
The –rdf in the symbcv command says bcv device <DEV> is remote i.e. is a bcv device on the remote array.
When you’re running your commands then you have to picture yourself (well you don’t but I do) standing locally on the host your running the commands on and think which devs appear local from there and which ones are remote.

Categories: Storage Tags:

Three types of 301 rewrite/redirect for apache httpd server

October 4th, 2011 No comments

Type 1:Exact URL without any query parameters:
www.doxer.org/portal/site/doxerorg/mydoxer/anyone
Type 2:Exact URL with any query parameters
www.doxer.org/portal/site/doxerorg/mydoxer/anyone?n=
Type 3:Exact URL plus query parameters and/or sub pages
www.doxer.org/portal/site/doxerorg/mydoxer/anyone / EVERYTHING AFTER THIS INCLUDED

For Type 1:
RewriteRule ^/portal/site/doxerorg/mydoxer/anyone$ http://www.doxer.org/shop/pc/anyone? [L,R=301,NC]
For Type 2:
RewriteCond %{QUERY_STRING} ^(.*)$
RewriteRule ^/portal/site/doxerorg/mydoxer/mydoxer/anyone/register$ http://www.doxer.org/shop/pc/anyone? [R=301,L,NC]
For Type 3:
RewriteCond %{QUERY_STRING} ^(.*)$
RewriteRule ^/portal/site/doxerorg/mydoxer/article http://www.doxer.org/mydoxer/latestnews? [R=301,L,NC]

Note:
1.In the destination URL, add ‘?’ to the end if you don’t want the query string to be auto-appended to the destination URL
2.[R] flag specifies a redirect, instead of the usual rewrite, [L] makes this the last rewrite rule to apply, [NC] means case insensitive

Categories: IT Architecture Tags: