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Solaris 10 Interview questions

Here is the basic Solaris interview questions which are commonly asked in Solaris L1 or L2 (Level 1 or L2) interviews.If you don’t have a Solaris setup to work,just install Solaris as guest operating system on VMware workstations and get a hands on experience.
You can also go through the below interface questions on specific category .
Explain the boot process of Solaris operating system?

Boot process dived into 4 phases.
POST: Power on self test, It will detect hardware, machine host ID,serial No, architecture type, memory and Ethernet address and it will load the primary program called bootblk.
OBP: Open boot programmable,
            1.Diagnosing all the system hardware and memory.
            2.Initializing the boot parameter.
            3.Creating device trees and load the boot block from (0-15 sector), it is called as secondary boot programmable ufsboot.
KERNEL INITIALIZATION: ufsboot load the kernel (generic unix), kernel will load all the necessary devices modules to mount the root partition to continue the booting process.
Init Phase : It will started by executing of /etc/init program and start other process reading the
                   /etc/inittab files, as the directory in the /etc/inittab files.
What is the difference between init 1 and init s ?
If you switch from multiuser mode to init s and switch it back to multiuser mode.then remote useres automatically reconnects to the system.where as in the case of init 1. they have to reconnect manully means they have to relogin

Explain about init phases
There are 8 run level.
Init0: Shutting down the system and bring back the system to OBP prompt (OK)
Init1: Single user mode for administrative
Init2: Multi user mode without resource sharing
Init3: Multi user mode with resource sharing
Init4: Not in use
Init5: Shutdown and power off the system
Init6: Reboot the system to default run level
Inits: Single user mode but user login are disabled
Explain rc script and run level
Rc script : check and mount the file system, start and stop the various process.
Run level: Base on the init phases 8 run level
Which file will take place while booting.
# /etc/inittab
How many file to modify the host name to be changed without rebooting the system.
There are 6 files.
#vi /etc/hosts
#vi /etc/nodename
#vi /etc/hostname.hme
#vi /etc/net/ticlts/hosts
#vi /etc/net/ticosts/hosts
#vi /etc/net/ticotsord/hosts
Where the ip address will be stored
# /etc/hosts
# /etc/hosts.equi
# /etc/hosts.hme
How to configure the network card
# ifconfig hme0 plumb
# ifconfig hme0 netmask up
# vi /etc/hosts ( update the ip address )
# vi /etc/hosts.hme0 ( update the ip address ) –> to bring the interface along with the ipaddress during boot time.
How to configure the virtual ip address
Infinity virtual ip address can be created.
# ifconfig hme0:1 plumb
# ifconfig hme0:1 netmask up
# vi /etc/hosts ( update the ip address )
# vi /etc/hosts.hme0:1 ( update the ip address ) –> to bring the interface along with the ipaddress during boot time.
How to find the network card speed
# ndd –get /dev/hme link_speed           
1 = 100mbps
0 = 10mbps
How to modify network card speed
# ndd –set /dev/hme instance 0
# ndd –get /dev/hme link_status
# ndd –get /dev/hme link_mode
             To modify
# ndd –set /dev/eri instance 0
# ndd –set /dev/eri adv_100T4_cap0
# ndd –set /dev/eri adv_100fdx_cap1
# ndd –set /dev/eri adv_100hdx_cap0
# ndd –set /dev/eri adv_10fdx_cap0
# ndd –set /dev/eri adv_10hdx_cap0
# ndd –set /dev/eri adv_autoneg_cap0
How to find the hardware configuration
OK banner –> from the open boot prompt
# prtconf
# sysdef
# /usr/platform/sun4u/sbin/prtdiag 
How will you find the number of hard disk
# format
#dmesg  –> this will not give the correct answer
#iostat –En  –> it wont show the Fibre channel
OK show-devs –> it will show the device scsi bus channel
OK probe-scsi-all –> This will deteck all the scsi bus channel, it will show CD-ROM/DVD-ROM also
Difference between probe-scsi-all and probe-scsi
OK probe-scsi-all: it will show all the scsi devices connected internal and external
OK probe-scsi: it will show only internal scsi devices connected
Procedure for Firmware upgrade
Shutdown root cron on csslu377 servers  
#./etc/init.d/cron stop
Reset the system controller from the console.
# resetsc -y
Upgrade the firmware on the system controller 
 > cd /114527-04 
> lom -G ./sgrtos.flash
> lom -G ./sgsc.flash
 Escape to lom> and reset the SC:  
lom> resetsc -y
Upgrade the firmware on the system boards:
> lom -G ./lw8cpu.flash
> lom -G ./lw8pci.flash
Shutdown the Operating System. 
#shutdown –i0 –g0 –y
This may take a while for the server to come up
> poweroff
> poweron
Which file to be configuring the logs messages (like: /var/adm/message etc…)
Which file maintain the kernel
# /etc/path_to_inst
This will be quite complicative, because kernel is the core of the operating system, its an image of the OS. whereas /etc/path_to_inst are the drivers are stored for the enabled hardware.
How will see the kernel version
Ok banner –> This will not show the Kernel
Ok .version  –> This will tell the open boot prompt version otherwords, FIRMWARE
# prtconf –V
# showrev –> will show the installed patches
# uname –x
How will see the hostname
How will compare 2 host patches
Through ftp copy the copied files nad use dd command to compare both the host patches.
use the command called “diff”
How will see the version of the patches
# showrev –p
# patchadd –P
How will check patches installed
# showrev –p  –> This is the correct one
# patchadd –P
# patchrm : to remove the patch
# patchad –d (patch no ) : to install the patch
How will you view the packages?
#pkginfo | more
When user logging in which file will take place
Default path for patches
# /var/sadm/patch
How many fields in passwd, shadow and group files
7 inPasswd: username:passwd:uid:gid:commentfiled:homedirectory:loginshell
9 in shadow: useraccount:passwd:lastchange:min:max:warring:inactivity:expiration:flag
4 in group: username:passwd:gid:user
Syntax for useradd commad
# useradd –u 101 –g other –d /export/home/ragu –m –s /bin/ksh –c “revenue” ragu
What is difference between g G while creating useradd?
Small “g”  is  primary group
Capital “G” is for secondary group
We have edit the /etc/passwd file and modify a user forget to give the shell will user able to loging?
If Passwd –f option given In which files it will update.
How many filed in /etc/vfstab
7 fileds
After creating swap file update the same to /etc/vfstab  what will be the fstype.
How will you clear the soft error on disk
# format à analyst & verify à read /write
How to modify the user from ragu to haz
# usermod –d /export/home/haz –m –l haz ragu
How will you find out enough memory?
# /use/platform/sun4u/sbin/prtdiag 
# prtconf | grep –i mem
What command can be used in running a background process?
# nohup ( comment ) &
How will you rectify the root passwd in solaris
Boot through cdrom 1/3 cd in single user mode.
Ok boot cdrom-s
# mount –F ufs /dev/rdsk/c0t0d0s6 /mnt
# cd mnt
#set TERM=vt100
#export TERM –> If you dont give, vi editor won’t start properly
# vi /etc/shadow  (remove the passwd entry and save the file)
# umount /mnt
# reboot     ( While system come up it will ask the new root passwd.)
If the system panic or system not booting
Boot through cdrom 1/3 cd in single user mode.
Ok boot cdrom-s
# mount –F ufs /dev/rdsk/c0t0d0s0 /mnt
# cd mnt
# installboot /usr/platform/’uname-i/lib/fs/ufs/bootblk /dev/rdsk/c00t0d0s0
# umount mnt
# boot –r
Explain /etc/inittab files
It will have 4 fields( id, rstat, action, process)
Respawn : Restart daemon if killed
Off : Don’t start the daemon if killed
Once: Run once
Wait: Wait for the process to be completed before processing the next line in /etc/inittab
How will you ad new aliases name
# vi /etc/mail/aliases ( enter the aliases name (eg) service:servicedesk@hotmail.com
# newaliases
# /usr/lib/sendmail –v –b (aliases name)
What are printer daemon
# /etc/inetd.conf –> This is an services daemons
# in.lpd daemon
Explain inode
It contain the information of the files and directory
Like ( date, home directory, rights, modified date, etc)
Explain /etc/system file
It will control the kernel modules and it dived into 5 sector
Moddir : default loadable kernel modules
Root.devices & root files configuration : Physical path name of the devices
Exclude: Does not load the kernel during kernel initializing
Forceload: Force the kernel module to load
Set: set maxium user =40
What is the protocol supported by NFS
What is the difference between dsk and rdsk
DSK: Block level devices
RDSK: Raw level device or character level device
How to find the boot path in solaris
# prtconf –vp | grep bootpath
# eeprom
How to bring the process to offline or online
# psradm –f (no of the process)
# psradm –a –n ( no of the process)
How to check the no of the processor available
# psrinfo –v
How will you check the process for particular user
# ps –U oracle
#ps –fu oracle | grep smon
How do you check the no of user logged into the system
# who
How do you check the run level
# who –r
How to enable the telnet or ftp session for one host
Edit the /etc/hosts.allow (it will have list of host to access) -> This will show the user list on that host.-
 /etc/hosts.deny (it will have list of host to access deny)-> This will show the user list on that host.-
 /etc/services file
If telnet not working, what are the thing to be checked
Ping test, service enable or not in (/etc/inetd.conf), NIS problem
If telnet is not working, first of all you will not be get connected, login through console access and then find out with ps -ef | grep telnetd or Kill -1 <pid_inetd>
In which file port No’s are defined
# /etc/service
Tell me the port for Telnet, ftp,nis,ssh,nfs
ftp = 21ssh = 22Telnet = 23nfs = 2049nis = 749
How will you restart the inetd process?
# Pkill –HUP inetd
What is nice and renice command do
To set the high priority for the process
-20 high priorities
+20 low priorities
Eg: # nice –20 oracle
What are thing you must ensure to provide security the system
1.    Latest patches
2.    Access to the system:
3.    Limited su access
4.    Stop unnecessary service at run level
      /etc/inetd.config : finger, discard, daytime,charger,tftp,spary & etc
How will you check the disk performance?
# iostat –xctd 4 5
What are performance tool used
Iostat ,vmstat , prstat , sar ,netstat, top
 Which service assign port no dynamically
Rpc service ( /etc/rpc)
As a user how he can change is passwd with root privilege.
Setuid to set on  /usr/bin/passwd  command
What is default permission of /etc/passwd , /etc/shadow files
/etc/passwd:  644
/etc/shadow: 400
What is default permission of files and directory?
file: 644
directory: 755
What is UMASK
UMASK is a Unix environment variable, which automatically sets file permissions on newly created files
Defalut value for umask
umask default value is 022
Explain setuid, setgid and stickybit
Setuid : When setuid permission set on a executable file, user who access the file is granted access permission of the owner of the file.
# find / -prem –4000
setgid : Permission similar to setuid, The process is changed to owner of the file.
# find / -prem –2000
Stickybit : It is a special permission that protect the files within a public writable directory
                  Stickybit permission set the shared directory, user can create a files or directory
                  But only by owner of the directory can modify or delete.
 # find / -prem –1000
How to set passwd never expire for a user
#passwd –x –1 (username)
How to find the kernel bit version or architecture
# isainfo –kv
How to set the time zion
# /etc/default/init
How to enable and disable the dtlogin
# /usr/dt/bin/dtconfig –e   ( enable)
# /usr/dt/bin/dtconfig –d   ( disable)
How to change the hostname and Ethernet address in single command
# /usr/sbin/sys-unconfig
How do you add the disk without reboot the server?
# devfsadm –c disk
How to delete “abc” files using find command
# find / -name “abc” –exec rm {}\;
What are the NFS daemon in server & client
  Server Daemons                                          Client Daemons
1 mountd                                                        statd
2.nfsd                                                             lockd
How to start / stop the nfs server
# /etc/init.d/nfs.server start
# /etc/init.d/nfs.server stop
How to find out the shared file system from server and client
Server : # share  & dfmount
Client : # showmount –e (hostname) and dfshares
To find the OBP environment variable
OK printenv
Expalin soft link and hard link
Softlink : link between different file systems and inode number will be different
                (eg) /U3 – /U4
#ln –s /U3/file1 /U4/file2
Hardlink : link between same file systems and inode number will be same
                (eg) /U3 – /U3
#ln –s /U3/file1 /U3/file2
Explain FSCK
Utility for checking and repairing the files system inconsistence due to abnormal shutdown.
It has 5 phases
Phase 1 : Check block and size
Phase 2 : Check pathname
Phase 3 : Check connectivity
Phase 4 : Check reference count
Phase 5 : Check cylinder group
 If super block corrupted how to recover
# newfs –N /dev/rdsk/c0t0d0s6
Then run the fsck utility using alternative super block
# fsck –F ufs –o b=32 /dev/rdsk/c0t0d0s6
How to create swap file
#mkfile 20m /filename
#swap –a /filename
#swap –l  ( to view and swap file)
#swap –d ( to delete the swap file)
What is difference between Hard and Soft mount?
Hardmount:Normal file system mount used mainly for mounting local file systems.
                 Once a file system is hard mounted, can use a normal filesystem untill
                  its umount.
Soft mount:It allows automatic unmounting if the filesystem is idle for a specified timeout
                 period. It is mainly used for network filesystems like NFS It can be configured
                 using Autofs and the network filesystem can be soft mounted.
Which command to lock the user Account?
# lk username
How to boot the solaris system in 64 0r 32 bit kernel
For 64 bit
# eeprom boot-file=”/kernel/sparc9/unix
OK printenv boot-file
OK settenv boot-file kernel/sparc9/unix
For 32 bit
# eeprom boot-file=”/kernel/unix
OK printenv boot-file
OK settenv boot-file kernel/unix
What are processing daemon in nis
What are the daemons in nis server.
Explain RAID0, RAID1, RAID3,
RAID 0 Concatenation/Striping
RAID 1 Mirroring
RAID 5-Striped array with rotating parity.
Concatenation: Concatenation is joining of two or more disk slices to add up the disk space. Concatenation is serial in nature i.e. sequential data operations are performed serially on first disk then second disk and so on. Due to serial nature new slices can be added up without having to take the backup of entire concatenated volume, adding slice and restoring backup.
Striping: Spreading of data over multiple disk drives mainly to enhance the performance by distributing data in alternating chunks – 16 k interleave across the stripes. Sequential data operations are performed in parallel on all the stripes by reading/writing 16k data blocks alternatively form the disk stripes.
Mirroring: Mirroring provides data redundancy by simultaneously writing data on to two sub mirrors of a mirrored device. A submirror can be a stripe or concatenated volume and a mirror can have three mirrors. Main concern here is that a mirror needs as much as the volume to be mirrored.
RAID 5: RAID 5 provides data redundancy and advantage of striping and uses less space than mirroring. A RAID 5 is made up of at least three disks, which are striped with parity information written alternately on all the disks. In case of a single disk failure the data can be rebuild using the parity information from the remaining disks.
Where will be the configuration for metadevice
How to grow disk size in SDS
1.Identified the free disks and the volumes size and meta device name
#df –h
/dev/md/dsk/d19         27G   1.5G    25G     6%    /rpbkup
2.Increase the /rpbkup by 10Gb
# metattach  d19 c4t50060E80000000000000818D00000009d0
3.Verify the volume size
#metastat d19
4.Increase the file system  /rpbkup by 10Gb
# /usr/sbin/growfs  -M /rpbkup  /dev/md/rdsk/d19
5.Verify the file system
# df-h
How to do the disk cloning on solaris
Here is the procedure
1.install the disk
you can do this few ways, let’s the scenario be, the disk is already attached and its been label through format.
2.If primary disk is u r c1t0d0s2
#dd if=/dev/dsk/c1t0d0s2 of=/dev/dsk/c1t1d0s2 bs=256k
This will take time, depends on the size of the primary disk
3.verfy the clone disk has a clean filesystem, for that
#fsck -y /dev/rdsk/c1t1d0s0 
4.To verify that mount the clone disk
#mount /dev/dsk/c1t1d0s0 /mnt
5.change the /etc/vfstab to point to the clone device
#vi /mnt/etc/vfstab
After making changes, boot the clone disk       —–Done
What is the physical device to check the 2 nodes connect in cluster
Physical fiber cable which is connect to the 2 nodes is called a HTEARTBEAT
How will you take ufsdump and ufsrestore in a sing command line?
# ufsdump 0f  – /dev/rdsk/c0t0d0s6 | (cd /mnt/haz ufsrestore xf -)
To check the status of the media inseted on the tape drive
# mt /dev/rmt/0 status
Syntex to execute a ufsdump
# ufsdump 0uf /dev/rmt/1
Difference between ufs and tar commnad
1. Used for complete file system backup.
2. It copies every thing from regular files in a file system to special character and block
    device files.
3. It can work on mounted or unmounted file systems.
1. Used for single or multiple files backup.
2. Can’t backup special character & block device files.
3. Works only on mounted file system.
What is different between crontab and at command?
Crontab: job can be scheduled
At: Job can be a run once only
What is difference between incremental backup and differential backup?
Incremental: Only those files will be included which have been changed since the last backup.
Differential: Only those files will be included which have been changed since the last Full backup
How many ufsdump level
0-9 level
0 = Full Backup
1-9 = Incremental backup of file,That have changed since the last lower level backup.
Options in ufsdump
S = size estimate amount of space need on tape
L = auto loaded
O = offline once the backup completed & if possible to eject the media
U = update the /etc/dumpdates files (Indicate:Name of the file system,Level of the backup 0-9,Date.
F = specified the tape devices name
Options in ufsrestore
T= list the content of the media
R =restore entire file system
X = restore only the file named on the command line
I = interactive mode
V = verbose mode
F = specified the tape devices name 
Disaster recovery steps if OS corrupted
Ok boot cdrom –s
# newfs /dev/rdsk/c0t0d0s0
# mkdir a
# mount /dev/dsk/c0t0d0s0 /a
# cd a
# ufsrestore rf /dev/rmt/0
# rm restoresymtable
# cd /usr/platform/’uname-m/lib/fs/ufs
# installboot bootblk /dev/rdsk/c0t0d0s0
# cd /
# umount /a
# fsck /dev/rdsm/c0t0d0s0
# init 6
from the OK prompt, execute
OK> boot -r
How will you comment error line in /etc/system file
# Vi /etc/system
   (To comment the error line in /etc/system files, we have to use *)
How many replicas should be for raid5 in sds if I have 5 disk
No of Hard Devices                                        No of State Database Replicas to created
      One                                                Three, all on one slice
      Two-four                                         Two on each drive
      Five or more                                    One on each drive
Cannot open ‘/etc/path_to_inst'”
System can not find the /etc/path_to_install file .It might be missing or corrupted and needs to be rebuild.
To rebuild this file  boot the system with  -ar option :
ok>boot -ar
Press enter to select default values for the questions asked during booting and select yes to rebuild /etc/path_to_install
The /etc/path_to_inst on your system does not exist or is empty. Do you want to rebuild this file [n]? y
system will continue booting after rebuilding the file.
What is mean by paging & server average time.
If a disk shows consistently high reads/writes along with , the percentage busy (%b) of the disks is greater than 5 percent, and the average service time  (svc_t) is greater than 30 milliseconds, then  one of the following action needs to be taken
Is it possible to edit the corntab using vi
It is not recommended but it is possible by editing
# vi /var/spool/cron/crontabs/root
The command to edit the crontab is
#crontab -e
Is it possible to create swap in new harddisk without format
“ No “ without label the drive, you can’t do anything
What is an alternative to the “top” command on Solaris?
# prstat –a
Thank you for reading this article.Please leave a comment if you have any doubt ,i will get back to you as soon as possible.


  1. What is default permission of /etc/passwd , /etc/shadow files?
    /etc/passwd: 444.

    /etc/passwd:644 is correct answer

  2. Thanks Lingeswaran.
    your Post it very helpful who is not in real time environment..

  3. Corrected.Thank you for notifying me.

  4. Arup Jyoti Thakuria

    Hi Team

    Need your help on the below—

    Need to add one database & listner as resouces to a resouce group,All are failover.Sun cluster 3.2,please help me with the steps.


  5. Why sometimes there is different output for /var in df -h and when we run du -sh inside /var?

  6. How to clear the soft and transaction errors for h/w disks in Solaris with out rebooting the server.

  7. Locking users password should be
    #passwd -l userid

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