LINUX-17 DISK QUOTA ON “XFS” (RHEL-7)

LINUX-17 DISK QUOTA ON “XFS” (RHEL-7)

A way to limit the users to eat disk space.

Quota can be implemented on behalf of,

·         Block size:     limit by block size

·         Inode no:       limit by inode/no of files

Limit is also differentiated in,

·         Soft Limit: For warnings, it’s like a barrier means if you jump the

 Barrier you will be notified about the jumping incident.

·         Hard Limit: No way, you jumped the barrier and we notified about your  daredevil act. Now we can not allow you to cross the limits.

LINUX-16 DISK QUOTA (RHEL-6)

LINUX-16 DISK QUOTA (RHEL-6)

A way to limit the users to eat disk space.

Quota can be implemented on behalf of,

·         Block size:     limit by block size

·         Inode no:       limit by inode/no of files

Limit is also differentiated in,

·         Soft Limit: For warnings, it’s like a barrier means if you jump the                   barrier you will be notified about the jumping incident.

·         Hard Limit: No way, you jumped the barrier and we notify about your  

               daredevil act. Now we can allow you to cross the limits.

LINUX-15 BONDING/NIC TEAMING IN RHEL-6

LINUX-15 BONDING/NIC TEAMING IN RHEL-6

[root@localhost ~]# cd /etc/sysconfig/network-scripts/

[root@localhost network-scripts]# cp ifcfg-Auto_eth1 org.ifcfg-Auto_eth1

[root@localhost network-scripts]# cp ifcfg-Auto_eth2 org.ifcfg-Auto_eth2

[root@localhost network-scripts]# cp ifcfg-Auto_eth3 org.ifcfg-Auto_eth3

[root@localhost network-scripts]# cp ifcfg-eth0 org.ifcfg-eth0

LINUX-14 JOB SCHEDULING (ANACRON)

LINUX-14 JOB SCHEDULING (ANACRON)

We studied about cron in previous post; it is enough to take care of my scheduled jobs.

Then Why anacron…??

Let’s say your company has not paid the vendor for AMC renewal. The UPS of rack is faulty. And the state electricity board has some problem which continues to next 10 days.

Now What…?

LINUX-13 JOB SCHEDULING (AT/CRON)

LINUX-13 JOB SCHEDULING (AT/CRON)

I am not in front of system, but there is very important task which must be done now…

How it is possible…?

Either I go to office and do that, or I share my root credentials with someone whom I trust and elaborate the whole task along with each and every command.

In my opinion, these are the only ways.

LINUX-12 ACCESS CONTROL LIST (RHEL-7)

LINUX-12 ACCESS CONTROL LIST (RHEL-7)

Well, all regular/special permissions are done. Our files/directories can be secured by several ways. I have too many tools for that.

Now relaxed……

And then I announced my great knowledge everywhere, my boss also heard about my knowledge, and assigned a task where I supposed to create a script which can be run by 4 users and members of 6 groups.

Great, now I can implement my super knowledge and stun my boss with my skills.

LINUX-11 ADVANCED PERMISSIONS (RHEL-7)

LINUX-11 ADVANCED PERMISSIONS (RHEL-7)

·         Advanced permissions (SUID, SGID, STICKY BIT)

·         ID command

STICKY BIT……………………..

Let’s imagine a condition,

Where there is a shared dump directory having access of 10 users. All users are allowed to create/delete files.

That’s very ideal condition, where all are happy.

User A has 10G of movies collection.

User B has 15G of CBT’s collection.

User C has 8G of games collection.

User D has 5G of songs collection.

LINUX-10 SPECIAL ATTRIBUTES & UMASK (RHEL-7)

LINUX-10 SPECIAL ATTRIBUTES & UMASK

·         Special file attributes

·         umask

SPECIAL FILE ATTRIBUTES……………..

What we learned till now about file perms are rwx with ugo.

Beyond that “rwx” we have other perm also,

“lsattr” to view the attributes and “chattr” to change the attributes.

[root@rhel7-server user1]# su - user1

Last login: Sun Jan  1 15:57:52 IST 2017 from 192.168.234.1 on pts/0

[user1@rhel7-server ~]$ pwd

/home/user1

LINUX-9 USER ENV & SHELL (RHEL-7)

LINUX-9 USER ENV & SHELL (RHEL-7)

• ·         USER ENVIRONMENT
• ·         SHELL STARTUP FILES (SYSTEM)
• ·         SHELL STARTUP FILES (USER)
• ·         LOGIN PROMPT
• ·         LOGIN SHELLS
• ·         HOW TO SET VARIABLES

USER ENVIRONMENT…………………………………..

Whenever a user logged in to system, environment comes in picture. It’s like a room decorated according to need.

Env. Can be created as per specific user basis as well as global basis means system wide.