Unix Command's Example

Following are the Unix command's:

>> How to see running Unix server is Virtual or Physical server.

Ans: Logging into unix with root user then type: vm and press tab key
[root@yourhost]# vm
vmstat                     vmware-config-tools.pl     vmware-toolbox-cmd         vmware-user                vmware-xferlogs
vm-support                 vmware-hgfsclient          vmware-uninstall-tools.pl  vmware-xdg-detect-de

This will indicate, this is the VM server. If you are not getting this details then Physical server.

>> How to see number of CPU or processes in Unix.

Ans: Logging with root user and type: cat /proc/cpuinfo
[root@yourhost]# cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 45
model name      :        Intel(R) Xeon(R) CPU E5-2640 0 @ 2.50GHz
stepping        : 7
cpu MHz         : 2500.000
cache size      : 15360 KB
physical id     : 0
siblings        : 4
core id         : 0
cpu cores       : 4
apicid          : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss ht syscall nx rdtscp lm constant_tsc ida nonstop_tsc arat pni ssse3 cx16 sse4_1 sse4_2 popcnt lahf_lm
bogomips        : 5000.00
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management: [8]

>> How to change the default authentication algorithms in Unix:

Ans: Logging with root user and perform the below command:#
For view, which authconfig are there:
authconfig --test | grep hashing

For setting the default authconfig set to sha 512
authconfig --passalgo=sha512 --update

Note: Why this is required as some time your user id and password won't work with your old user id and password.

You will get such information, where as count start from 0 and end -1.

Have good day ahead!!!