My Hibernation

It seems like I have been unplugged from the real net for a while. It is just __good__ to stay connected. My blogging hobby was off the list, when I reached Bangalore. Well, now it is time to break the silence.

The File-system dilemma

I recently bought Seagate GoFlex FreeAgent Desk 2TB 3.5inch [ :( ] hard-disk. And I wanted to know which is the best file-system suited for my use.

I usually use ext2 for my pen drives. I wanted to know that, is there any added advantage using btrfs over ext4. My use is to store books of size (usually <20 MB ). Seperate partition for movies and tvseries ( 300MB < avg-size < 4GB) and tutorials (size <100MB) and lecture videos (size <350MB).

After some discussion I decided to go for ext4. And this post explains why.

When formatted to Ext2
command $: mkfs.ext2 -L "" /dev/sdb1
Disk /dev/sdb: 2000.4 GB, 2000398933504 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0006ec2e

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1      243202  1953513472   83  Linux

When Formatted to Ext 4
It took painstaking 18 minutes

I personally prefer to use ext4 after reading this link.
Also ext reserves 5% disk space for root.

The reserved blocks are there for root's use. This allows the system to continue running if non-root users fill up the file system and also assists in preventing file fragmentation because the filesystem does not fill up completely.

So, in short, if the drive doesn't contain /var or /tmp, then there's not much point in having space reserved for root.
You can get that space back. By using tune2fs It is a good tool.

sudo tune2fs -r 0 /dev/sdX to disable it. /*Here we set the "-r=reserved-blocks-count" to zero */

Some forums prefer that minimum 1% is recommended. You can modify the percentage of reserved block percentage too using tune2fs.

sudo tune2fs -m 1 /dev/sdX to modift it. /* Here we modify (-m) "reserved-block-percentage" to 1% from the default 5% */

My earlier plan to format to Btrs was foolish at this point of time as it lacks tuning and debugging support. And gave a 100GB buffer space with the inferior FAT32 and 30 GB with NTFS so as to connect to my friend's computers using windows.

With a larger maximum file size, fast fsck and journal checksumming ,  I chose ext4. Some benchmarking showed that ext4's sequential read is better than sequential write as ext2 makes lesser writes than ext4 thereby increasing lifetime for your flashdrives.

Though ext4 makes more sequential writes to disks degrading performance for drives with data rarely modified. Unnecessary writes to your device can be avoided by using noatime flag in mount. You can over ride the default mount option again with tune2fs.

Further Read

• Migrating to Ext4
• Barriers and Journaling File Systems
• Discussions in forums
• noatime mount option
  

 

The File-system dilemma

When formatted to Ext2
command $: mkfs.ext2 -L "" /dev/sdb1
Disk /dev/sdb: 2000.4 GB, 2000398933504 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0006ec2e

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1      243202  1953513472   83  Linux

When Formatted to Ext 4
It took painstaking 18 minutes

I personally prefer to use ext4 after reading this link.
Also ext reserves 5% disk space for root.

The reserved blocks are there for root's use. This allows the system to continue running if non-root users fill up the file system and also assists in preventing file fragmentation because the filesystem does not fill up completely.

So, in short, if the drive doesn't contain /var or /tmp, then there's not much point in having space reserved for root.
You can get that space back. By using tune2fs It is a good tool.

sudo tune2fs -r 0 /dev/sdX to disable it. /*Here we set the "-r=reserved-blocks-count" to zero */

Some forums prefer that minimum 1% is recommended. You can modify the percentage of reserved block percentage too using tune2fs.

sudo tune2fs -m 1 /dev/sdX to modift it. /* Here we modify (-m) "reserved-block-percentage" to 1% from the default 5% */

My earlier plan to format to Btrs was foolish at this point of time as it lacks tuning and debugging support. And gave a 100GB buffer space with the inferior FAT32 and 30 GB with NTFS so as to connect to my friend's computers using windows.

Further Read

• Migrating to Ext4
• Barriers and Journaling File Systems
• Discussions in forums
  

--
Arjun S R
http://about.me/arjunsr

Insecure Vodafone femtocells allow eavesdropping, call fraud

Insecure Vodafone femtocells allow eavesdropping, call fraud

via Ars Technica by peter.bright@arstechnica.com (Peter Bright) on 14/07/11

Hackers have reverse engineered the femtocells used by British mobile operator Vodafone, and discovered that they can be used to eavesdrop on callers and used to fraudulently place calls and send text messages. Femtocells are being used increasingly often to provide better phone reception in areas with a weak signal. They contain short-range mobile base stations—typically with a range of 30-60 feet—paired up with Internet connections. Users within the range of the femtocell have their calls routed over a home Internet connection to the mobile operator's system.

Vodafone calls its femtocells Sure Signal. The Sure Signal costs £50, and supports up to 32 phone numbers belonging to 3G phones or Internet dongles. They can be used by any Vodafone customer, whether contracted or pay-as-you-go, with an Internet connection of 1Mbps or faster.

Read the comments on this post

Jan-Lokpal vs Joke-pal

A mail I got. Thought, its worth sharing it.
--
Arjun S R
http://about.me/arjunsr

---------- Forwarded message ----------
From: Ricken Patel - Avaaz.org <avaaz@avaaz.org>
Date: Thu, Jun 30, 2011 at 15:48
Subject: Jan-Lokpal vs Joke-pal
To: "arjun1296@gmail.com" <arjun1296@gmail.com>

To ensure you receive emails like this, add Avaaz to your contacts (how?). Or, click here to unsubscribe.
Dear friends across India,

The Government is breaking its promise to Anna Hazare and proposing a toothless "Joke-pal" bill. On Sunday, they'll appeal to all the opposition parties to stand with them in defending the corrupt status quo. Let's flood the parties with faxes in the next 72 hours calling on them to represent the people of India and support Jan-Lokpal not Joke-pal:

The Congress party is breaking its promise to Anna Hazare to agree on a strong bill and proposing their own sarkari Joke-pal provisions which make the bill toothless. To get the Joke-pal passed, they're appealing to all the other political parties to stand with them in defending India's corrupt status quo -- holding an all-party meeting this Sunday.

The BJP and other parties have already spoken out strongly for parts of Jan Lokpal, now it's time for them to put words into action and prove to us that they share our desire to end corruption.

The parties all pay close attention to the faxes they receive from citizens -- let's flood them with faxes calling for Jan Lokpal, not the sarkari Joke-pal. Add your voice now by clicking the link below or editing in your own personal message -- our tool will fax the message to the leaders of the BJP, CPI, CPI(M), SP, TMC, JD(U), and the rest of the political parties:

http://www.avaaz.org/en/jan_lokpal_vs_joke_pal/?vl

Sunday is a crucial day for our Democracy -- a special all party meeting -- to set the terms of the historic Lokpal. For the government, the all party meeting is a chance to win allies for undercutting the Lokpal's most vital anti-corruption tools. But for us, this is a major opportunity to get the opposition to endorse the people’s version!

Corruption is a problem for virtually all the political parties, so there will be strong pressures in each of them to endorse the Joke-pal bill. But through massive citizen engagement we've forced the Congress party to at least include Jan Lokpal as an option -- now through the same pressure we can press the opposition parties to choose it.

Faxes are the best way to reach party leaders on this urgent timeline. Click below to use a simple online tool to edit your own message or to send a pre-drafted letter by fax to all 17 party leaders, and help build our numbers by forwarding this email to friends and family:

http://www.avaaz.org/en/jan_lokpal_vs_joke_pal/?vl

Across the country, a movement against corruption has exploded, driving a media storm of pressure. Politicians have and will try every trick in the book to wriggle out of their promise to us and to Hazare. But every time they do we can come back even stronger -- showing that our will to fight corruption is stronger than their will to defend it.

With hope,

Ricken, Saloni, Ben, Shibayan, David and rest of Avaaz team.

SOURCES:

Manmohan Singh calls all-party meeting on Lokpal Bill on July 3
http://articles.economictimes.indiatimes.com/2011-06-25/news/29703009_1_lokpal-bill-anna-hazare-monsoon-session

Treat both Lokpal drafts equally: Team Anna
http://timesofindia.indiatimes.com/india/Treat-both-Lokpal-drafts-equally-Team-Anna/articleshow/9019704.cms

Government not presenting factual picture of civil society's Lokpal Bill draft
http://economictimes.indiatimes.com/news/politics/nation/government-not-presenting-factual-picture-of-civil-societys-lokpal-bill-draft-shanti-bhushan/articleshow/9019727.cms

BJP deplores UPA for "delaying" Lokpal Bill
http://ibnlive.in.com/news/bjp-deplores-upa-for-delaying-lokpal-bill/162399-37-64.html

Lokpal: Anna reaches out to govt, Opposition
http://ibnlive.in.com/news/team-anna-reaches-out-to-govt-may-meet-sonia/163726-37-64.html

Support the Avaaz community! We're entirely funded by donations and receive no money from governments or corporations. Our dedicated team ensures even the smallest contributions go a long way -- donate here.

---

Avaaz.org is a 9-million-person global campaign network that works to ensure that the views and values of the world's people shape global decision-making. ("Avaaz" means "voice" or "song" in many languages.) Avaaz members live in every nation of the world; our team is spread across 13 countries on 4 continents and operates in 14 languages. Learn about some of Avaaz's biggest campaigns here, or follow us on Facebook or Twitter.

This message was sent to arjun1296@gmail.com. To change your email address, language, or other information, contact us via this form. To unsubscribe, send an email to unsubscribe@avaaz.org or click here.

To contact Avaaz, please do not reply to this email. Instead, write to us at www.avaaz.org/en/contact or call us at +1-888-922-8229 (US).

Finger simulated with RPC

The link is -->
 https://github.com/arjunsr /myfinger

Click on the download button and do it as tar.gz file.

There is a README file attached

Just extract it
tar xvzf .tar.gz

There is a tutorial file. just go to the project tree directory and execute
"./play_tutorial"

compilation overhead is solved by to naive scripts ./clientcompile and
./servercompile scripts. Could have used "make" but was lazy. So
kindly bare with that.
Sorry once again to overkill the problem