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Monday, December 22, 2014

How to mount RAID1 volume on Ubuntu

If you ever need to mount an encrypted partition from a RAID1 NAS on your Ubuntu system (like a laptop or a different server) here's a simple three steps instruction. Figure out what partition needs to be mounted (you can do it by running parted or similar to figure out what your target should be); for the sake of the example it will be /dev/sdd2. And now:

% sudo mdadm --assemble --run /dev/md0 /dev/sdd2
% sudo cryptsetup -v luksOpen /dev/md0 mapperpoint
% sudo mount /dev/mapper/mapperpoint /mnt/external/

If you need to check the state of the drive while connected via USB enclosure, run
% sudo smartctl -aH -d sat /dev/sdd
The only trick is to add -d sat disk type.

Or to simplify the whole thing, just run Disk Utility and click "Start RAID" button ;)

Friday, November 28, 2014

Finally upgrading from Debian Lenny

If you like me was putting of an upgrade from Debian 5.0 Lenny you might find yourself blocked out, because ftp.us.debian.org/debian/dists/lenny doesn't exist anymore anywhere on the US mirrors. However, I needed to do one last update before getting on dist-upgrade. 

Luckily enough I was able to find a mirror in Germany which still has Lenny dist around. So, if you find yourself in my shoes edit /etc/apt/sources.list on your system and replace 
 ftp://ftp.us.debian.org/debian/
with
 ftp://ftp.de.debian.org/debian-archive/debian/

then do usual update and then an upgrade. Good luck!

Monday, July 7, 2014

Mark Twain and data science

When I look at data science nowadays it reminds of
In the space of one hundred and seventy-six years the Mississippi has
shortened itself two hundred and forty-two miles.  Therefore ... in the Old
Silurian Period the Mississippi River was upward of one million three hundred thousand miles long ... seven hundred and forty-two years from now the Mississippi will be only a mile and three-quarters long.  ... There is something fascinating about science.  One gets such wholesome returns of conjecture out of such a trifling investment of fact.
                 Mark Twain
I don't know why...

Sunday, June 15, 2014

Hadoop genealogy simplified

I have decided to simplify the elephant genealogy tree by separating pre-Hadoop 2.x part out of it. The new supported version will only be reflecting Hadoop 2.x. The last updated full version of the diagram is available for anyone from my github workspace under the tag WDD4

Tuesday, April 22, 2014

Smart-ass recruiters out there....

An spam-email from a recruiter (target company name isn't mentioned _anywhere_):

   I came across your resume on Dice and would like to talk to you about
   a Hadoop Engineer position with our client, which is a Fortune
   10 company based in Cupertino, CA. This is the largest and most
   valuable consumer electronics/technology company in the world today
   which makes cutting edge smart phones, personal computers & music
   players. 


Now I wonder which one of us is an idiot?

Thursday, March 20, 2014

Git is absolutely fabilous, of course

After using git for like 5 years - and shall I say I know most of the tricks in the book and outside of the book ;) - I still find some neat things in it, that please me immensely in spite of being simple.

I am doing this Gradle implementation of Apache Bigtop build system and thought that would be about time to split one Gradle file in two: separation of concerns and all that stuff. So, naturally I have fired-up IntelliJ IDEA, did some splitting, and copying, and other things. Got all my functionality working to the same extend as it were. And now it is time to commit: I have original build.gradle and new packages.gradle files. So,

% git commit -a -m 'Separating build logic into its own module'

[BIGTOP-1201 f319b55] Separating build logic into its own module
2 files changed, 53 insertions(+), 429 deletions(-)
rewrite build.gradle (90%)
rename build.gradle => packages.gradle (90%)

Seriously, how smart and cool is that?

Tuesday, March 4, 2014

Hadoop Genealogy: continued (#4)

In the good tradition of helping people to understand the intricacies of Hadoop ecosystem and what versions are coming from where I am updating the popular Hadoop genealogy chart. Enjoy!


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