How to deal with NIM concepts and interview questions?
Filesets Required
bos.sysmgt.nim.master
bos.sysmgt.nim.spot
nimd
and nimesis – daemon will get started. Else restart the inetd / start the above
daemons
startsrc
–g inetd
startsrc
–s nimd/ nimesis
Daemons Required:
a)
bootp protocol (BOOTPD)
This is the initial communication made between NIM master and client during
network boot.
b)
Trivial File Transfer Protocol (TFTPD)
It is used to transfer lppsource,SPOT and other resources from NIM server to
NIM client during the NIM client booting.
Check
the services are running,
#lssrc
-ls inetd
bootps
/usr/sbin/bootpd bootpd /etc/bootptab
active
tftp
/usr/sbin/tftpd tftpd
-n
active
#grep
bootps /etc/services
bootps
67/tcp # Bootstrap
Protocol Server
bootps
67/udp # Bootstrap Protocol Server
#grep
tftp /etc/services
tftp
69/udp
# Trivial File Transfer
tftp
69/tcp # Trivial File
Transfer
If
the above services are not enabled, start the same.
#chubserver
-v bootp -p udp -a
#chubserver
-v tftpd -p udp -a
#refresh
-s inetd
#startsrc
-g nfs (Also, ensure NFS group related
services are also enabled.)
Important Directories and
Files
a) /tftpboot
When we create SPOT, kernel is copied into /tftpboot directory . All kernles of
NIM clients are in the direcotry
root@aixnim1: /etc # ls
-l /tftpboot
lrwxrwxrwx
1 root
system 34 Dec 19
18:36 aix21.domain.com -> /tftpboot/spot_5200-08.chrp.mp.ent
-rw-r--r--
1 root
system 1276 Dec 19 18:36
aix21.domain.com.info
-rw-r--r--
1 root system 9379964
Dec 8 15:31 spot_5200-08.chrp.64.ent
-rw-r--r--
1 root system 9260943
Dec 8 15:31 spot_5200-08.chrp.mp.ent
b) /etc/bootptab
File which authenticate nim client for remote boot up for nim operations like
bos installation, restoration & maintenance boot. Based on the NIM
operation, nim client info update and once the NIM operation completed, entry
also removed automatically from this file.
In simple words, authenticates NIM client for remote boot up.
#tail /etc/bootptab
aix21.domain.com:bf=/tftpboot/aix21.domain.com:ip=10.200.50.56:ht=ethernet:sa=50.20.100.48:gw=10.200.50.1:sm=255.255.255.0:
The fields are separated
with colon (:) and attributes are separated with equal sign (=):
first
field - NIM client name
bf - boot file name
ip - NIM client IP address
ht - hardware type
sa - TFTP server address for the boot file
gw - gateway used by client to reach the server
sm - subnet mask for the nim client
c) /etc/niminfo
The file always exists on the NIM master and client. contains information about
who is master and client, port no, protocol informations.
This is automatically generated when master was created and client was
registered to master. This file was not manually edited. If any corrupted, want
to be removed and recreated.
How
to define the client: #smitty nim_mkmac
How
to define the resource: #smitty nim_mkres
How
to initiate the installation: #smitty nim_bosinst
How
to Rebuild on Master: #nimconfig -r
How
to Rebuild on Client: #nimint -a master=<MASTER_HOSTNAME> -a
name=CLIENT_NIM_NAME>
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