Monday, November 27, 2006

The OpenSolaris Quiz - FOSS.IN/2006

These are OpenSolaris Quiz questions presented in FOSS.IN/2006 These answers are mine and disclaimers apply here. I am putting it here, since I found the questions good enough to make me interested toward OpenSolaris

Edit: Please consider the questions only and not the answers. Attended the BOSUG, and Ananth helped in confirming a few answers. Some went over my head though









The OpenSolaris Quiz - FOSS.IN/2006




1. Which Computer Scientist who co-founder the Apache HTTP server servers as a board member of the OpenSolaris CAB.

Roy Thomas Fielding



2. On a Quad core, dual processor machine, how many times can the DTrace probe 'profile:::tick-17hz' fire in a span of 3 seconds



17



3. What does this Dtrace one-liner do ?

proc:::signal-send { printf("%s - %s". args[2], args[1] - }



Trace all the signals sent to all the processes running on the system.



4. 256 Quadrillion Zetabytes is a significant number as regard ZFS. This is the amount of data required to fillup a ZFS filesystem. How many digits are there in that number ? (when expressed as bytes)



39

5. Expand COW in the context of ZFS.



Copy on Write.



6. FreeBSD = Ktrace, Linux = strace , Solaris = ?



truss (dtrace is way too advanced :-))



7. Which binary / libc function enables seamless execution of 64 and 32 bit binaries on a 64 bit OpenSolaris machine ?



isaexec.



8. How do you encrypt a file with AES algorithm using the OpenSolarius Cryptographic Frameword ?



encrypt -a aes -i file.txt



9. Which is the distro wholly created by the Bangalore OpenSolaris community ?



Belenix



10. How many privileges does OpenSolaris have by default ?



48



11. Which OpenSolaris project is underway to introduce virtualization in networking ?



CrossBow.



12. What is the latest Source Code Management System used to OpenSolaris development ?



Merucrial / Hg



13. Write down a minimal fool proof "C" function which takes a (void *) pointer as the argument and returns :

0 - if it is an invalid userland pointer

1 - If the pointer points to a valid userland address backed up by a page. No core dumps, No signal handling. (Elegant Solutions = ++ points)



shh...shh...Answer is something I may be able to figure out after studying C :-D



14. Write a DTrace script to print the absolute path of ALL files being opened by processes running in a system.

Note : Your script should not throw any kind of errors when being executed.



dtrace -n 'syscall::open*:entry { printf("%s %s",execname,copyinstr(arg0)); }'



15. Draw an approximate diagram that explains the code-flow when a system callis called from a kernel thread

Syscall ==> Kernel panic :-)

16. Give three expansions for the acronym BFU which would be valid in the OpenSolaris World.



a) Blinding Fast Upgrade

b) Big Fucking Make

c) Bonwick-Faulkner Upgrade



17. Assuming you could completely populate a zpool to its theoretical limit

Qa) Find the approximate energy required to do the same (in Electron Volt)



7.488 x 1046



Qb) Find the Mass Equivalnet for the energy



136 billion kg



18. You want to find out how many minor faults occur from the time your kernel loads till the time you get your login prompt during boot. How would you go about doing it ?



dnk again. It must be a dtrace script. I will try to write one once I install OpenSolaris.



19. SMF automatically manages dependencies betweekn services.

a. What is the ideal data structure to store the dependency information ?



Sorted Tree / Graph



b. What is the best algorithm to find the order in which the serices should be started ?



Topology Sort



20. Using any or all of the new and old technologies in OpenSolaris, write about a really wild or cool project that you would like to implement.



I hardly know of any technology of OpenSolaris in detail :-(. I am looking for clustering and building a NAS using ZFS. I got some idea, but will try to do a bit after going home only.

4 comments:

Anonymous said...

Many of the answers are wrong. Even at places where you have not marked DNK.

HJKL a.k.a h2l said...

That made me sad :-( Anyway I liked the questions..I wish I will get the answers in the next BOSUG

Ananth said...

Hey ! Good show mate. You have missed the answers to some of the interesting ones. You should walk over to the Next BOSUG meet - we can discuss the answers. Some of them are quite funny ;-)

HJKL a.k.a h2l said...

Wow..Your comment came in just right after I read about FOSS second day in your official blog, http://blogs.sun.com/ananth/. I must say you guys have done a great job there. BTW the quiz made me read a lot about OpenSolaris ZFS and Dtrace after the FOSS. So special thanks to the person who compiled the questions.