Monday, August 17, 2009

Changing boot parameters

Open a terminal and do the following:
Type sudo
Type vim /boot/grub/menu.1st
Press Insert key
Make necessary changes
Press Esc key
Type :wq! and press Enter key

You can change the timeout value to your preference. During bootup after that number of seconds without any key press, the default OS will be automatically booted unless the user manually chooses one at boot time.

To cange the default boot OS simply change the value in default=X. The numbers are counted from 0. For eg if the OS you want to boot by default is the third title in your menu.1st file then make the following change:
default=2

To change the names displayed for the operating systems at the boot menu simply change the title in the menu.1st file.

To comment a line in the menu.1st file, simply add a # symbol at the start of the line.

To remove an entry from boot menu, either comment or remove the lines for that particular entry from the menu.1st file. The lines to remove will include a title line and two or three option lines below it in the menu.1st file.

To add Windows entry into GRUB menu, add the following lines at the end of menu.1st file:
#windows
title Microsoft Windows
root (hd0,X) - where X is windows partition no
savedefault
makeactive
chainloader +1

P.S. Before making changes to menu.1st file it is good to backup your existing file by typing the following in a terminal:
cp /boot/grub/menu.1st /boot/grub/menu.1st_backup
In case you corrupt the boot file you can restore it by reversing the above command:
cp /boot/grub/menu.1st_backup /boot/grub/menu.1st

Recover boot loader

If any os like Win XP is installed on a sytem running linux, the linux boot loader GRUB gets overwritten. This creates problems as the windows boot loader NTLDR is unable to boot linux. To solve this issue simply restore GRUB as the boot loader and you can dual boot both linux and XP. To restore GRUB try any one of the following methods:
  • Insert a linux installation CD and enter the Rescue mode. If such a boot option is not visible, type "linux rescue" at the boot : prompt. At the terminal which opens, type the following one after the other, where X is the partition containing linux. To find this simply type "root (hdO," and hit the tab key, which will display the partitions on your disk. Choose X as the one with type Ox83 :
grub
root (hdO,X)
setup(hdO)
quit

  • Boot into a live CD environment. Open a terminal and type the following commands sequentially :
sudo grub
find /boot/grub/stage1 - output will be like (hdO,X)
root (hdO,X)
setup(hdO)
quit
reboot
  • The third method is using the graphical Recover options that come with certain distros of linux. Simply enter the recovery mode with the installation CD in the drive during boot. There will be automated recovery options for restoring GRUB. However this is not available with all distros of linux.

Tuesday, July 28, 2009

MM Module - SAP

MM stands for Materials Management. The following steps are involved in purchasing goods and services through the MM module in SAP:
  1. User requirements
  2. Service/Material specification
  3. Purchase Requisition (PR)
  4. PR Release
  5. Request For Quotation (RFQ)
  6. Compare vendor terms
  7. Choose vendor
  8. Purchase Order (PO)
  9. PO Release
  10. Service entry
  11. Service accepted
  12. Invoice Verification
  13. Payment
In the case of goods, steps 10 and 11 are replaced by Goods Receipt (GR).
The vendor can be chosen according to different criterion. Normally L1 method is used whereby the vendor with lowest bid is chosen. Goods to be purchased can be classified into three categories :
  • Revenue expenditure - day to day expenditure
  • Capital expenditure - funds allocated for a new project or maintenance
  • Destined for warehouse - items to be stored in warehouse bins
MRP (Material Requirements Planning) based procurement ensures that shortage of a material item never occurs. MRP maintains three limits for a material, namely safety stock, minimum stock and maximum stock. When th level of an item falls below the minimum stock, MRP automatically generates PR for (maximum stock - minimum stock) numbers of that item.

Sunday, July 26, 2009

Useful websites

Laptop technology & reviews
Free software
Video tutorials
  1. ShowMeDo
ebooks
  1. Ebook Share
Windows XP troubleshooting
  1. Windows Tips
  2. Mera Windows

Saturday, July 25, 2009

Guitar exercises : Increasing finger speed

There are 6 strings numbered 6-1 from top to bottom, labelled E A D G B E respectively and 20 frets.A good strumming exercise to increase finger speed is pluck the first 4 frets of 6th string ,then first 4 frets of 5th string and so on upto 1st string.. Then pluck the 2nd,3rd,4th,5th frets of 1st string,then of 2nd string and so on upto 6th string. In this manner proceed upto the last fret..
Also keep practising the scales as regularly as possible..
Now onto a trick to identify chord families. It's the 1st, 4th and 5th chords when taken in alphabetic order(A-G-A..) starting from the main chord..For eg to find the chords in G major family write G A B C D and choose the 1st, 4th n 5th. Thus the chords in G major are G C D..Similarly for A major A B C D E, the chords in the family are A D E..
For more tips refer to the included video on guitar tips by the master himself, Joe Satriani..I've tried his exercises and believe me they are damn effective if you practise on a regular basis..

Containers vs Paravirtualization

Containers virtualize only an OS's operating environment..Paravirtualization virtualizes part of an OS's operating environment but also selectively emulates the hardware devices that a virtualized OS requires..A future technique being considered is known as pre-virtualization which is an automated version of paravirtualization..
Examples :
Containers : Linux -VServer
Paravirtualization: Xen

Paravirtualization is better than containers because containers support only native applications..Also a kernel crash would affect all the users on a container based system..However containers offer better performance in some ways..For further material on this refer to the following link :
Linux and Open Source: Containers vs. Xen: Everyone wins!

Friday, July 24, 2009

Technical Writer - Career Path

I've always enjoyed working with computers, tweaking them, troubleshooting issues,trying out new softwares etc..Hence i did my bachelors in computer science..However i've found that im not into the whole programming,algorithms stuff..Lately i've been searching for a career option that would enable me to work with computers but not go into the boring programming line..
It's called TECHNICAL WRITING..It involves working extensively with software products and creating the help documentation..The help documentation includes both the online help and the help menus that come inbuilt with the software..It's basically simplifying the complex technical stuff for a layman so that he can navigate and use the software easily..For more information on this line of work refer to the following site :
www.words4nerds.com
Don't know if this is for me but it is certainly enlightening to know there are such career options out there..

Saturday, July 18, 2009

HP laptop recall

Guys i had a hp laptop 2 yrs old..the display conked out a few months back..jst recently i found out that it was a design flaw..something to do with a faulty fan algorithm that resulted in overheating..hp has released a new bios update to resolve the issue by updating the fan algorithm..so if you have a similar issue do check up on the hp site if your product number is among those eligible for a free repair..
The affected models include :
Hp Pavilion dv2000/dv6000/dv9000 and Compaq Presario V3000/V6000 series
Another issue that could occur is wireless adapter not detected in device manager..it's good that hp is giving a free repair..
The following links will help you identify if your laptop is eligible for a free repair :



Saturday, July 4, 2009

SAP

That's Systems, Applications, Products in data processing..It was developed by SAP AG, a company based in Germany..It's an ERP(enterprise resource planning) software used to manage the various departments in an enterprise..
The modules which may include SD(Sales and Distribution), MM(Materials Management), FI(Financials Accounting), CO(Controlling), HR etc all share a common database..There is thus a presentation server(sapgui.exe), an application server and a database server..SAP uses the ABAP(Advanced Business Application Programming) language..The number and type of modules may vary depending on the industry(IS - Industry Specific)..

SAP started as SAP R/1(Financial accounting system), proceeded to SAP R/2(Mainframe business management) and is now in SAP R/3(client-server distributed architecture)..The cost and time to implement SAP in an industry depends on it's size and complexity..Once implemented it helps in getting real time data processing done..SAP certifications are done in either of the modules and generally takes about a month..

Monday, January 26, 2009

Bash Shell Tutorial

Linux uses the Bourne-again(Bash) shell. A few of the must know commands for working your way through the shell
pwd : show path of present working dir
ls : list contents of pwd
cd : change dir
rm : to delete files, to delete dir use the -r flag with rm
emacs : text editor to open file
su : switch user
sudo : execute a command with temporary root privileges
chmod : change privileges for a file, value 777 specifies r,w,x for root,group and others
ps : list current processes
kill : stop processes that are not responding
poweroff : shutdown system
reboot : reboot system
init : switch between run levels, 5 is the default run level for multi-user, networking and gui
/etc/init.d/gdm stop : to stop the gnome desktop manager and enter shell mode
/etc/init.d/kdm stop : to stop kde desktop manager
startx : start the xserver
ifconfig : configure network adapter
All services are in the /etc/init.d directory

mount : to mount hard drives, cds
mount -t iso9660 /dev/cdrom /media/new : will mount a cd in the new folder in media dir
mount -t ntfs /dev/sda1 /mnt/c : will mount ntfs partition 1(scuzzy device)in c folder in mnt dir
umount : to unmount a mounted drive, if device busy error comes use -l option for lazy unmount
To automount a partition on boot add the mount entry to fstab file in /etc directory

cp : copy
mv : move
man : this is the most useful command, typing man command will give you the manual pages for that command which describe the command in detail and how to use it

ctrl+alt+(F1-F6) : enters any of the six available terminals
ctrl+alt+F7 : switch back to gui mode from the terminal


rpm -i : to install an red package manager package
rpm -e : to remove an installed rpm package

To manually compile a binary executable with a make file, execute the following sequentially
./configure
make
make install

For a complete guide to master the shell commands, refer linux guides like the Red Hat guide. A good video for learning linux is given by CBT nuggets.
The best way to learn linux is through experimentation, use a virtual software if ur reluctant to install linux. Qemu with pendrive linux is what i used to learn and experiment with linux. It is available for download at the following link :
http://www.pendrivelinux.com/portable-qemu-persistent-pendrivelinux/
Using this u can run linux within windows, just like any normal windows app without rebooting or installing anything.

Sunday, January 25, 2009

Lightweight Virtualization

It is the latest trend in virtualization. There are 2 techniques, containers and paravirtualization.
Containers virtualize an OS's operating environment, not the hardware.
Paravirtualization virtualizes part of the operating environment and selectively emulates necessary hardware.
Both these are faster and much more efficient than traditional virtualization.
So, those of you working on VMWare and other traditional virtualization platforms, try out the new products like XenSource's Xen and Linux -VServer. Other free packages include Qemu and Boch's.
As for why go for virtualization, the benefits are limitless. Try out all unstable software and do all your experimentation in virtual environments without affecting your host OS or valuable data. Run multiple servers on a single server hardware.

Thursday, January 22, 2009

A few computer tips

Speed up the boot process
Run msconfig utility from start->run. In the startup tab uncheck non critical items.Be careful not to remove items in the system 32 dir.

Set the page file as static
Go to start->control panel->system->advanced.
Click on virtual memory settings.Go to advanced tab and click change.Set initial size and maximum size as the same, optimally 1.5 times the system RAM.

Leave a few Gb of free space in C: drive and defrag regularly


Few Amazing Videos!!!

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