News for December 2009

Backup & Restore the Volume in Linux Single User Mode

service network start
ifconfig eth0 ip netmask
service portmap start
mkdir /tmp/remote
mount -t nfs -o tcp,port=2049 nas:/volume1/share /tmp/remote
rpm -ivh /tmp/remote/rmt*
rpm -ivh /tmp/remote/dump*
dump 0f /tmp/remote/host.dump /dev/VolGroup00/LogVol00
 
mkdir /tmp/local
mount /dev/VolGroup00/LogVol00 /tmp/local
cd /tmp/local
restore rvf /tmp/remote/host.dump &> /tmp/remote/host.log &
Posted: December 31st, 2009
Categories: os, rhel
Tags: ,
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Getting into B-School ”Round 2 Essays” What Not to Do

Following was from the BusinessWeek Forum.

Getting into B-School ”Round 2 Essays” What Not to Do

From: timpower

To: All

You’ve seen a large number of posts from us and many others on what you should do with your essays. Knowing what not to do is probably as important, if not more, than what to do and our essay reviewers (alums from Wharton, HBS and Stanford) pulled together the list below for our blog at http://essaycritique.blogspot.com

So, DON’T:
1. Exceed the word count

2. Use “I realized” ad nauseum – we actually have a tool that counts what we call absolutely overused essay phrases and this is top of the list..

3. Gloss over the details – the AdCom is more interested in understanding the specifics of what you did than the broad, high level generalizations that you felt during the situation you are describing

4. Say “I was enchanted” or enraptured or captured or any such magical sounding verb – c’mon, were you really?!

5. Suggest that you were in the epicenter of the financial crisis and helped solve it – unless you really did.

6. Say you volunteered or are a ‘community service’ type of guy if you are not. If you are, say where, when, how and how much.

7. Use every essay to talk about your career. You need at least one “personal” essay, if not two (depending on the school that you are applying to)

8. Blame everyone but yourself in your ‘failure’ essay. Even though you might not think you have, revisit it – we can’t state how many people do this because its embarrassing.

9. Ignore the question. As plainly obvious as this might sound, after you have written your essay, re-read your answer once to only check for this – have you answered each component of the question that is asked and done it justice?

10. State the obvious. Let your discussion of situations and experiences naturally lead the reader to your conclusions – e.g., after describing a particularly challenging time in your life, don’t say “this experience was extremely challenging” – they get it. Hope this helps – you know where to find me!

Tim Power

Posted: December 31st, 2009
Categories: education
Tags:
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SSH Client Side Configuration

Host *
LogLevel=ERROR
StrictHostKeyChecking=no
ConnectTimeout=10
Posted: December 24th, 2009
Categories: macosx, os, rhel, solaris
Tags:
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Disabling the GUI on Solaris 10

Prior to Solaris 10, modifying the initdefault in /etc/inittab would determine if the the GUI was loaded upon boot up. With Solaris 10, execute the following to disable the GUI…

/usr/dt/bin/dtconfig -d
/usr/dt/bin/dtconfig -e
Posted: December 24th, 2009
Categories: os, solaris
Tags:
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Enabling the Write Cache on Sun Hardware with raidctl

raidctl -p "wp=on"
Posted: December 22nd, 2009
Categories: os, servers, solaris, sun
Tags: ,
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NetApp Deduplication

Source: http://communities.netapp.com/docs/DOC-1060

FAQ NetApp Deduplication 08_25_08.pdf

3. HOW DO I ADD THE DEDUPLICATION CAPABILITY TO A FAS SYSTEM?

Installing the nearstore and a_sis licenses on a supported system will enable the deduplication capability. Although these licenses must be requested by the customer, there is no charge for either license. Note: R200 systems do not required the nearstore license.

9. IS THERE A MINIMUM DATA ONTAP RELEASE REQUIRED FOR NETAPP DEDUPLICATION?

Yes. NetApp deduplication for FAS requires the installation of Data ONTAP 7.2.4 or greater. NetApp deduplication for V-Series requires Data ONTAP 7.3 or greater.

21. WHAT PROTOCOLS DOES NETAPP DEDUPLICATION SUPPORT?

NetApp deduplication is independent of protocols and thus supports all NetApp SAN and NAS protocols: iSCSI, FCP, NFS, and CIFS

22. ARE THERE ANY SPECIAL CONSIDERATIONS IN USING DEDUPLICATION WITH LUNS?

NetApp deduplication operates regardless of protocol. However, LUNs are a somewhat special case because of reservations and space guarantees. The default mode of deduplication and LUNs is to apply any space savings to the snapshot reserve area. However, If LUN space guarantees are disabled, and the snapshot reserve set to zero, LUNs can be deduplicated and “thin provisioned.”

24. CAN I ESTIMATE MY SPACE SAVINGS BEFORE INSTALLING DEDUPLICATION?

Yes. A space savings estimation tool (SSET) is available to NetApp and Partner SE’s. This tool is a standalone application that operates on a Windows or Linux client and will “crawl” through any NFS volume (up to 2TB) and will estimate the amount of space savings you will get with deduplication.

25. CAN PREVIOUSLY WRITTEN VOLUME DATA BE DEDUPLICATED?

Yes. NetApp deduplication can scan and deduplicate existing data on a volume. This can be run at any time on a volume that contains previously written data, and is recommended to be run whenever deduplication is first enabled on a volume.

29. CAN I MANUALLY START AND STOP THE DEDUPLICATION PROCESS?

Yes. You can initiate the deduplication process at any time with a CLI command, and also stop it at any time with a CLI command.

30. CAN THE DEDUPLICATION PROCESS BE AUTOMATED?

Yes. The default operation of deduplication is to automatically begin deduplication of a volume if a 20% new data change rate is detected since that last time deduplication was run. If the user prefers regularly scheduled or manual deduplication, this automatic feature can be turned off.

31. HOW OFTEN SHOULD DEDUPLICATION BE RUN ON A VOLUME?

The frequency of deduplication scheduling depends on the frequency that redundant writes are taking place on the volume. Typically, deduplication might be run approximately once per week on the volume. If more frequent redundant writes are taking place, for instance nightly SQL database dumps, then running deduplication more frequently may be recommended.

33. HOW DO I VERIFY THE SPACE SAVINGS WITH DEDUPLICATION IN A GIVEN VOLUME?

Use the “df –s” command to verify the cumulative space savings per volume. The results are listed in number of blocks and % saved. An example of the output from this command:

> df -s /vol/VolPST Filesystem used saved %saved /vol/VolPST/ 24072140 9316052 28%

49. CAN I DEMO DEDUPLICATION FROM THE DATA ONTAP SIMULATOR?

Yes. The Data ONTAP 7.3 simulator supports deduplication.

Posted: December 21st, 2009
Categories: netapp, storage
Tags: ,
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Git Talks from Randal & Linus

Git Talk by Randal

http://www.youtube.com/watch?v=8dhZ9BXQgc4

Git Talk by Linus

http://www.youtube.com/watch?v=4XpnKHJAok8

Posted: December 19th, 2009
Categories: git, programming, version control
Tags:
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Recovering Lost Apple iPhoto Pictures during a failed iPhone Photo Import

During a iPhoto import from my iPhone, my iPhoto froze. The only thing I could do was execute a force quit. Unfortunately half the photos originally on my iPhone were deleted.

To recover those photos from my iPhone, I launched the terminal and went to the ~/Pictures/iPhoto Library/Data/2009. Within the directory, I saw the date stamp for today and I was able to recover my photos.

 

cd ~/Pictures/iPhoto Library/Data/2009
Posted: December 14th, 2009
Categories: macosx, os
Tags: ,
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Accessing Yahoo Mail via POP

Had a whole bunch of mail to pull down from Yahoo. Installed FreePops and within minutes, I downloaded all the messages.

http://www.freepops.org/en/download.shtml

Posted: December 14th, 2009
Categories: Uncategorized
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Backing up the Subversion Repository using HotCopy & Dump

Using svnadmin hotcopy and svnadmin dump to backup the repos.

#!/bin/bash
 
TARGET_DIR=/subversion/admin
svnadmin hotcopy /subversion/repos/MYREPO ${TARGET_DIR}/MYREPO
svnadmin dump /subversion/repos/MYREPO -r 0:HEAD > ${TARGET_DIR}/MYREPO.dump
Posted: December 13th, 2009
Categories: subversion
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