computer science related thread

[MADDY]

appadina I am more familiar with C# and .net

i'm with ESPN and SUNTV programmes ...

as a sys admin, i have never been able to give a convincing answer to any of our clients/IT managers as to why "reboot always works" from a calculator to high end super dome servers ......can anyone explain here

i think u ask this...if im elimentary pardon me

normally the application crashes due to the incorrect access of data or storing data in incorrect address inside RAM.Shortly,its accessing or writing data in address space of other programs .so when the code sections of a program inside the ram is overwritten by some other program the application crashes.

the memory dump can be viewed to see what has happened when the applications crashed.

to overcome this,when a system is reboot the RAM is completely cleared and refreshed.the programs are newly loaded from the hard disk to the fresh and clean ram.In short,the program that is corrupted was removed completely from the ram(ofcourse along with all other programs) and the the program in loaded from the harddisk to the RAM newly.

now when the code that is corrupted is that of the OS(kernel),then its os crash.

idha pathithana ask paneenga

yes u r 100% right - and nothing is elementary in computer world ..........and anbu_kathir's link was also very informative...thanks

i dont know how it explains reboot of calculator or some storage boxes which just have a processor and disk arrays

[Vivasaayi]

MADDY,

calculator also has memory.when u reset the calc with the pin backside the calc the memory is reset back to the factory settings.

calculator has an embedded os in it.Its is a typical example of embedded system.embedded system is the deicated operating system as u know.

it handles the input,output and memory operations

just like computer.but a dedicated operating system-embedded system.

[app_engine]

This is a "sametime connect" question -

At times it "hangs" (means I cannot invoke anyone for a chat window while sametime shows all of them as active - green squires).

What is the command line option to reset and restart sametime? I didn't know and had to reboot the computer this morning

(Similar thing also happens at times with the lotus notes and I used to reboot...then one lotus notes guy helped me with the command line option : cd \notes and then nsd -kill. Is there a similar kill to sametime and if so what is the command?)

The above example also illustrates that sometimes it could be a bug in the application that "hangs" it (not related to RAM clash or HDD error). We can continue to use the machine for other apps, but if we want the specific app, reboot helps (i.e. if we don't know to kill the specific executable to restart the app).

[app_engine]

I have observed that sometimes such bugs (like the one above with sametime and notes) are not related to the main functionality of the app but the interaction with the network device on the machine and the server. Mostly related to "reconnect" errors. 99 times out of 100 they reconnect properly (when we disconnect lan cable and reconnect or get out of a "good-wireless-signal" range momentarily and then get back in) but occasionally 'hang'

[app_engine]

Digital telephone systems (telephone exchanges and other switching equipments) are another example of embedded systems (most of them using realtime OS) and often prone to "hanging" (my experiences were with a lot of beta systems and situation is much worse there).

AhAh, andha 'reset' switch mattum illAtti, life rombakkashtam Sometimes when I'm stuck with some real-life problems, I wish there is a reset switch)

[Vivasaayi]

Anyone into Embedded systems here

[app_engine]

[quote="Vivasaayi"]Anyone into Embedded systems here[/quote

I was, i.e. till 2002.

[Vivasaayi]

does anyone have the idea of why "inode" index of filesystems starts from 1 unlike the array index which starts from 0.

i need to know it urgently

[Vivasaayi]

indha questionukum yaravadhu answer therinja post pannunga

" what should happen if the kernel attempts to awaken all the processes sleeping on an event,but no processes are asleep on the event at the time of wakeup"

[selvakumar]

does anyone have the idea of why "inode" index of filesystems starts from 1 unlike the array index which starts from 0.

i need to know it urgently

I am not sure on this since I have lost my touch on kernel related stuffs. My Guess - What about super block ? For calculation of block, block 0 could be (Not sure) assigned for Super block.. illaya
Let me try.