LINUX-8 USER LOGIN / SU

LINUX-8 USER LOGIN / SU

TERMINAL: Special-purpose physical devices which usually had a screen and a keyboard, and attached to a computer via a serial line, either directly or via a dial-up modem. Terminals were quite dumb devices, with little computation capabilities by their own: their job was mainly to display fixed-sized text coming via the serial line from the computer, and send data entered via the keyboard to the computer through the serial line, much like a teletype but with a screen in place of paper.

A device known as terminal which contains only few parts and a monitor with integrated keyboard is used to access the mainframe computer. Terminal connects with mainframe computer on serial console port. Once connected it uses all resources such as CPU, RAM and Hard disk from mainframe computer. The earliest terminals were also known as teletypes (abbreviated TTY).

LINUX-7 USER MANAGEMENT (RHEL-7)

LINUX-7 USER MANAGEMENT

User Types:     Root / Regular / Service

Root: user with administrative privilege

Regular: user level rights, can’t perform admin tasks.

Service: service user means user who take care of installed services like                    apace, ftp, mail, ntp, postfix, qemu…etc…

User account info for local users are located at…

/etc/passwd     user info

/etc/shadow     user’s password info

/etc/group      group info

/etc/gshadow    group config file

LINUX-6 SERVICE MANAGEMENT (RHEL-6)

LINUX-6 SERVICE MANAGEMENT (RHEL-6)

Start | stop | adjust run level of services and their status

Available tools are,

1.  Chkconfig (shell)

2.  Ntsysv (TUI)

3.  System-config-services (GUI)

4.  service

CHKCONFIG:

Will list all service installed, with their corresponding run level settings.

LINUX-5 DISK & FILE SYSTEM OPERATIONS

LINUX-5 DISK & FILE SYSTEM OPERATIONS

What we are about to learn,

·         Prtitioning

·         MBR/GPT Partitions

·         View partition table

·         Disk types

·         Creating Partitions with FDISK/GDISK

·         Deleting Partition

·         Creating File System

·         Mounting / Unmounting

·         Permanent Mount

·         Disk Buffer/Cache

·         Adding Swap Partitions

·         Adding Swap Files

·         Making Swap Partitions/Files Permanent

·         Automatic Mounting (Fields in /etc/fstab)

·         Various Mount Options in /etc/fstab

LINUX-4 YOUR FILE SYSTEM (XFS)

    LINUX-4 YOUR FILE SYSTEM (XFS)

XFS is a highly scalable, high-performance file system which was originally designed at Silicon Graphics, Inc. XFS is the default file system for Red Hat Enterprise Linux 7

Main Features

XFS supports metadata journaling, which facilitates quicker crash recovery. The XFS file system can also be defragmented and enlarged while mounted and active. In addition, Red Hat Enterprise Linux 7 supports backup and restore utilities specific to XFS.

LINUX 2 DEVICES

LINUX 2 DEVICES

Devices are special type of files stored at /dev dir.

[root@rhel7-server ~]# ls -l /dev

total 0

crw-rw----.          1 root video    10, 175    Nov 21 18:12 agpgart

drwxr-xr-x.          2 root root         300    Nov 21 18:37 block

lrwxrwxrwx.          1 root root           3    Nov 21 18:12 cdrom -> sr0

brw-rw----.          1 root floppy    2,0 Nov 21 18:12 fd0

prw-------.          1 root root          0 Nov 21 18:12 initctl

srw-rw-rw-.          1 root root           0 Nov 21 18:12 log

what are the c / d / l / b / p and s at the starting ?

LINUX-3 Hardware & Devices

LINUX-3 Hardware & Devices

  

COLD PLUG & HOT PLUG TYPE DEVICES:

Cold plug devices are mostly the expansion cards plugged in to motherboard and installation of these requires down time where as hot plug devices can be installed while system is up.

COMMANDS:

#lshw (-short)

#lshw -class disk -class storage    

#lspci (-tv) lspci -v | grep "VGA" -A 12  

#lsscsi (-s)

#lsusb (-v)

#lscpu

Veritas Volume Manager-15 (vxedit & vxmend)

================================VXEDIT================================

RENAME===============

DISK….

# vxedit -g mdg rename d2 newd2

SUBDISKS….

# vxedit -g mdg rename d2-01 newd2-01

PLEX…..

# vxedit -g mdg rename plex-01 newplex-01

VOLUME…..

vxedit -g mdg rename stvol  newstvol

Veritas Volume Manager-14 ( Veritas Licencing Info)

/opt/VRTS/bin/vxlicrep

root@pr01:>/# vxlicrep

Symantec License Manager vxlicrep utility version 3.02.61.004

Copyright (C) 1996-2012 Symantec Corporation. All rights reserved.

Creating a report on all VERITAS products installed on this system

 -----------------***********************-----------------

   License Key                         = xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

   Product Name                        = VERITAS Storage Foundation Standard HA

   Serial Number                       = 34876

   License Type                        = PERMANENT

   OEM ID                              = 2006

   Site License                        = YES

   Editions Product                    = YES

Veritas Volume Manager-13 (Mount Lock/Unlock)

root@pr01:>/# mount -F vxfs -o mntlock=vxvm /dev/vx

vx/       vxfen     vxfend    vxportal

root@pr01:>/# mount -F vxfs -o mntlock=vxvm /dev/vx/dsk/mdg/mrvol /mrvol-test/

UX:vxfs mount: ERROR: V-3-21264: /dev/vx/dsk/mdg/mrvol is already mounted, /mrvol-test is busy,

                 or the allowable number of mount points has been exceeded.

root@pr01:>/# umount /mrvol-test/

root@pr01:>/#

root@pr01:>/# mount -F vxfs -o mntlock=vxvm /dev/vx/dsk/mdg/mrvol /mrvol-test/

root@pr01:>/#

root@pr01:>/#

root@pr01:>/# mount -F vxfs -o mntlock=vxvm /dev/vx/dsk/mdg/mrvol /mrvol-test

root@pr01:>/#

root@pr01:>/#

Veritas Volume Manager-12 (Administrative Tasks)

Here we will get some basic Idea of..

• VOLUME MANAGER RUNNING PROCESSES
• VXVM PATH
• VXVM INSTALL LOGS
• VXVM PACKAGE INFO
• N COLUMNS & ST WIDTH
• DG VERSION
• VXSTAT
• VXTRACE
• VXTASK
• VXNOTIFY