Saturday, 28 February 2015

GPT issue and solution

Modern systems coming with two type of BIOS options:
1.UEFI specification
2.Legacy.


if you Legacy and deactivate UEFI option you can install redhat simply by having /boot option. If you go with default option UEFI then you have to do installation by creating::

you have to create /boot/efi instead of only  /boot.

then after installation   you cannot be able to use "fdisk" option any more. because now you are working in GUID partition table (GPT) not in MBR.

which is the newfangled replacement for the tired and inadequate MS-DOS partition table, and why you might want to use it instead of the familiar old MBR. GPT is part of the UEFI specification, and because Linux is a real operating system with modern features you can use GPT with both UEFI and legacy BIOS.

The Globally Unique Identifiers Partition Table is the modern replacement for the antique MS-DOS Master Boot Record (MBR). The MBR was born in the early 1980s for IBM PCs, way back in the thrilling days of ten-megabyte hard disks. The MBR must live on the first 512 bytes of your storage device, and it holds the bootloader and partition table. The bootloader occupies 446 bytes, the partition table uses 64 bytes, and the remaining two bytes store the boot signature. The MBR is limited to four primary partitions, and a single primary partition can hold an extended partition which can then be divided into logical partitions. Linux supports (theoretically) an unlimited number of logical partitions. In the olden days Linux maxed out at 63 IDE partitions and 15 SCSI partitions because the kernel was limited in the total device numbers it could allocate. udev allocates device numbers dynamically, so those limitations are gone.
fig-1 GPT partitions
Figure 1: GPT has just partitions, not primary and logical partitions.
The MBR is tiny and inflexible, and has lasted this long thanks to clever hacks to get around its limitations. Logical Block Addressing (LBA) gets around the limitations of its original cylinders, heads, and sectors (CHS) addressing. The traditional hard disk block size of 512 bytes limits partitions to 2TB in size, though more clever hackery supports the new 4096-byte sectors for a maximum 16TB partition size.











GPT: GPT is part of the Unified Extensible Firmware Interface (UEFI) specification, and on Linux you don't need an EFI BIOS to boot from a GPT partition, but can use it with legacy BIOS systems

GPT does not have primary and logical partitions, but just partitions as GParted

TO use "gdisk" for GPT you have to install the "gpt rpm package". https://www.dropbox.com/s/qmkzocja04s9rv7/gdisk-0.8.10-159.1.x86_64.rpm?dl=0 .

so if you use fdisk you will be get an error and if ty to use gdisk you are not able yo use that without gpt package. ashow below




to see the UUID details "#blkid "  command has been used.
you can convert MBR partition to GPT in between the installation

inject "CTRL+ALT+F2" during your installation process to go on command line with 'parted' utility.


#parted
(parted) print /dev/sdb
 (parted) select /dev/sdb
(parted) mklabel gdt
(parted) yes
print /dev/sdb
quit
then return to installation process with CTRL+ALT+F6

 for Disk partition you can use:

Cfdisk is a linux partition editor with an interactive user interface based on ncurses. It can be used to list out the existing partitions as well as create or modify them.
Here is an example of how to use cfdisk to list the partitions








Tuesday, 3 February 2015

Second Method : How to Share the Folder with Guest as Window OS and Linux on VMware

  create folder in WINDOW OS and share it with full permissions
 then check the ip of the VMware Network Adapter with command :ipcomfig

  ping from LINUX terminal with that IP as ping 192.168.56.1
if every thing OK you will get reply back

 As shown above do the all setting and press connect button
A new window will open as shown below give the username domain and password of the system as shown below and you will get the shared data
ENJOY :-)
 


if you are not able to enter into the .bashrc file and commands like 'ls' and 'vi' are not working
and you are getting some error like this:  command couldnot be located because '/bin' is not included in the PATH environment variable
then type  this :

export PATH=/usr/bin:/bin

problem will be sorted out