Monday, 15 August 2022

Storage Management in Linux PART-2 | RHCSA| Part-33 | Practice in RHEL8 on AWS| Hindi | System Admin

 1. lsblk - To List all Block Devices

lsblk
2. mount - To Mount partition on a particular Directory
mount /dev/< Disk Name > <Directory name>
3. umount - To Unmount a Directoy from a Partition
umount <directory name> o <mount point>
4. fdisk - To Create a MBR Partition
fdisk /dev/<partition name>

Wednesday, 10 August 2022

Storage Management in Linux PART-1 | RHCSA| Part-30 | Practice in RHEL8 on AWS| Hindi | System Admin

 Master Boot Record(MTB)

32 Byte

4 Primary (3p + 1E)

total partition = 15

max 2tb


GPT

GUID Partition table Globally Unique Identifier

64 Byte

total partition = 128

8Zib tb

8 billion tb


STORAGE MANAGEMENT
1) DAS (Direct Attach Storage) :- Pen Drive , HD

2) NAS (Network Attach Storage) :- NFS , SAMBA

3) SAN (Storage Area Network) :- over the Network Shares complete disk 



Monday, 8 August 2022

Process Management in Linux PART-3 | RHCSA| Part-29 | Practice in RHEL8 on AWS| Hindi | System Admin

  Kill - Kills the Process

1. TERMINATE
kill <PID>
kill -15 <PID>
kill -TERM <PID>
2. KILLING
kill -9 <PID>
kill -KILL <PID>
3. STOP
kill -19 <PID>
kill -STOP <PID>
4. CONTINUE
kill -18 <PID>
kill CONT <PID>
5. UP TIME - It Shows the First Output Line of TOP CMD
uptime
6. LSCPU - This Show All Details related to CPU
lscpu


Sunday, 7 August 2022

Process Management in Linux PART-2 | RHCSA| Part-28 | Practice in RHEL8 on AWS| Hindi | System Admin

 NAME FLAG KERNEL DEFINED STATE ANDDESCRIPTION

Running R Task_Running :- The process is either exeuting on CPU or waiting to run . Process can be executing user routines or be
queued and ready when in Running state .
Sleeping S Task_ INTERRUPTIBLE :- The Process is waiting for some
condition . When a Signal Satisfies the condition , the process
returns to Running.
D Task_UNINTERRUPTIBLE :-This Process is also Sleeping
but Unlike S - State does not respondto signals. Used Only When process interruption may cause an unpredictable device state.
K Task_KILLALE :- Identical to the uninterruptible D state but modified to allow a waiting task to respond to the signal that it should be killed .
I Task_REPORT_IDLE :- A Subset of state D . The Kernel does not count these process when Calculating load average . Used for Kernel threads.
Stopped T Task_STOPPED :- The Process has been Stopped Usually by being signaled by a user or another process. The process can be Continued by another signal to return to running.
T Task_TRACED :- A Process that is being debugged is also
temporarily stopped and shares the same T:state flag.
Zombie Z EXIT_ZOMBIE :- A Child Process signal its parent as it exits. All Resources execpt for the process identify PID are released.

X EXIT_DEAD :- When the Parent Cleans up the remaining child process structure . The Process is now released Completely . This Stae will never be Observed in process- listing utilities.



Thursday, 4 August 2022

S-Permissions in Linux PART-1 | RHCSA|Part-25| Practice in RHEL8 on AWS| Hindi|Devops & System Admin

 Instead of Giving Write Permission to all of these Paths / etc/passwd /etc/group /etc/shadow /etc/gshadow . You can Simply Give Write Permission to Only Others Section of this Path - /usr/sbin/useradd.

** If You Want to Run Any Program or Script you can use SUID. You can Run Those Files With Root User Easily But Your Files Will Not Get Permissions on Files
chmod u+s <File / Directory Name>
u-s < File / Directory Name>