Solaris 10 System Administration - Part I

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Solaris 10 System Administration Interview Questions

1) How does Solaris operating system boots? 

The boot procedure of the operating system can be divided into four categories namely:

1. Post
2. Obprom
3. Init phases
4. Kernel initialization

2) Can you explain each of the phases involved in booting the operating system? 

Post – As you switch on the power, it will identify the hardware and certain other information such as system ID, memory division, serial number, architecture type and IP address. In addition, it also loads a program which is known as bootblk.

OBPROM –This abbreviation stands for open bootable program. It helps –

1. Diagnose hardware and memory of operating system.
2. Create device subdivision and load book block from 0-15 sector and it is known as secondary book programmable ufsboot.
3. Initialize boot functions.

Kernel Initialization – In this stage, ufsboot loads the kernel which in turn loads all necessary modules of the device. This is further required for root partition that helps continue with the booting procedure.
Init stage – It starts as you execute the init program and begin other program reading /etc/inittab files, similar to the directory in the form of /etc/inittab files.
 

3) What to use to use ‘top’ command on Solaris operating system? 

An alternative to the ‘top' command is to use ‘# prstat –a’ while working on the above mentioning operating system.
 

4) What do you understand by Solaris? 

It is a UNIX based operating system which supports workstations and server operating from Sun. It can also be regarded as a recognized operating system which is widely used. Further, it is available from server vendors and also known as the successor of sun operating system.
 

5) How many types of installation of the OS are available and explain each of them? 

There are seven types of installation of Solaris operating system and they are as follows:

Solaris installation program is the general way in which you can install the OS with the help of DVD or CD ROM.
Installation procedure over network – Installing the operating system using a server that has easy access to Solaris disc images.
Flash installation – With the help of this process, the installation can be carried out via a master system.
Custom jumpstart installation – This process is known as a command line interface in which several systems can be installed or upgraded at the same time using the profile created.
Solaris Live Upgrade process – This can be done even when the current operating system environment is running.
WAN BOOT process – This can be carried out installing the operating system over a wide area network via HTTP.
Solaris zones – After the installation of the operating system is completed, ‘Zones’ can be configured and installed. One such is the global zone which can be considered as the currently running operating environment.

 
6) How many RAID levels are present in this operating system? 

RAID stands for Redundant Array of Inexpensive or Independent Disks. It has six levels such as RAID Level 0 – RAID Level 6.
 

7) Do you have any idea about run levels in Solaris operating system? 

There are mainly eight run levels in this operating system, and they are as follows:

0 – it is used during power down state
s or S – for single user
1 – administrative state
2 – Multi-user state
3 –multi-use with NFS state
4 – alternative multi-user
5 – power down
6 – Reboot state

 
8) How can you end any process in this operating system? 

Whether you are a superuser or root user, you should know how to terminate the process of another user on the operating system. In addition, to terminate any process, you also need to obtain PID of the process.
 

9) In this operating system, can you explain the difference between dsk and rdsk? 

DSK is a block level device. FS which is formatted is known as block device. Rdsk is a raw level device in this operating system.
 

10) How can you find reserve space of disk? 

# fstyp –v /dev/rdsk/c1d0s0 | grep minfree
minfree 6%  

 
11) How to find out the location of alternative backup superblocks? 

# newfs –N /dev/rdsk/c0t0d0s2

 
12) Do you know how to reduce reserved disk space while working on this operating system? 

Yes, the reserved space can be reduced to 2% using ‘# tunefs –m 2 /dev/rdsk/c1d0s0.’

 
13) What are the steps to check for installed packages? 

# pkginfo |more
# pkginfo –l

 
14) Explain About Admin Command? 

Local Kerberos services can be managed by administering policies, key tabs and principles by managing the admin command. Admin.local is used to master KDC and it does not require any authentication. On the server login information is passed through a secured server. It checks the principle name by the value of the user environment variable.

 
15) Explain About The Command Prof_attr? 

This forms the RBAC profile database. It displays the relationship between among the profiles in the database. It also gives authorizations between navigation for those files. One of the samples is Solaris.admin.fsmgr.read.solaris.admin.serialmgr.read.

 
16) Explain The Differences Between Setting Files Using Octal Codes And Symbolic Codes? 

The main difference between setting files using octal and symbolic code files is symbolic codes are relative whereas octal codes are numeric codes. These settings will remain unless you change the settings explicitly by using symbolic codes. If group execute access gets executed it automatically removes write access permission.
 

17) What Is The Best Solution To Avoid Large Number Of Groups? 

The best solution for not creating large number of groups lies with the system administrator. It is best to use structural group membership which reflects organizational divisions. To manage file access a system admin can use access control lists.

 
18) What Is Umask? 

Wide set permissions can be set by using umask which can set write, read and execute permissions on new files created by the user. These settings can be made from the command line to reflect broad settings. It can also be set from the global system settings file. Umask command displays all the settings made with that command.
 

19) How Can You Determine Whether A File Is Setuid? 

The easiest way to determine whether a file is setuid or not by checking for files which are owned by the root and after checking for files that are owned by root you can check for s flag files assigned to the user permissions. In the permission table the first s refers to setuid root.
 

20) Explain About Sticky Bit Permissions? 

This command helps the network administrator to relax a bit. This command will not allow the deletion of the common files present in the common area. This command helps the users by not allowing them to rewrite on other files. Certain permissions can be set which will restrict users to delete files created by them.
 

21) Explain About The Command Ls? 

Ls command gives a way to the main directory and also gives access permissions for files in Solaris. It displays and prints user and group ownerships, file access permissions, filename and files size and creation date.

 
22) Explain About The Limitations Present In Sudo?

There are some limitations for sudo which makes RBAC popular they are:
·      It is not possible to assign a user to work on specific file or profile.
·      It is also not possible to assign a user to work on a specific command.
·      By using shell commands and certain functions it is possible to have some restrictions on a user but it would consume time for a larger setup.

 
23) What Is Sudo? 

Sudo maintains database of all the privileges assigned to a user name. These privileges can be identified by different commands present in the database. This feature helps a user to format a disk but the root system cannot be changed.
 

24) What Are The Different Ways To Execute Profiles? 

Profiles can be executed in many different ways some of them are:
·      Pfexec executes a single command in profile.
·      With some restrictions pfsh and pfcsh can be executed.
·      By directly logging into the account using su.

 
25) Are The Three Different System Management Roles? 

There are three different roles specified by Solaris they are:
·      Primary administrator who is responsible for security.
·      System administrator is responsible for day to day roles.
·      Operator is responsible for data back up and maintenance.

 
26) What Is Rbac? 

RBAC is introduced into Solaris for managing specific tasks. These specific tasks are based and defined in the administrator profile. It is based on the standard developed by NIST. RBAC is a very important tool for performing multiple tasks. It also separates tasks which require high technical knowledge from low ones.
 

27) Set The Display Automatically For The Current New User? 

– export DISPLAY=`eval ‘who am i | cut -d”(” -f2 | cut -d”)” -f1’`Here in above command, see single quote, double quote, grave accent is used. Observe carefully.
 

28) Display The Processes, Which Are Running Under Your Username? 

– Ps .aef | grep Mahesh vjHere, Mahesh vj is the username.
 

29) List Some Hot Keys For Bash Shell? 

Ctrl+l . Clears the Screen. Ctrl+r . Does a search in previously given commands in shell. Ctrl+l – Clears the typing before the hotkey. Ctrl+a . Places cursor at the beginning of the command at shell. Ctrl+e . Places cursor at the end of the command at shell. Ctrl+d . Kills the shell. Ctrl+z . Places the currently running process into background.
 

30) How To Know The Date And Time For . When Script Is Executed? 

Add the following script line in shell script. Eval echo “Script is executed at `date`” >> time info.inf Here, .timeinfo.inf. Contains date & time details ie. When script is executed and history related to execution.
 

31) What File Do You Put The Umask Setting In? 

The UMASK value for Bourne and korn shell users can be modified system wide by editing the “umask” entry in the “/etc/profile” file. To change the default UMASK for the C shell, modify the UMASK variable in “/etc/default/login” file.
 

32) Which Nfs Daemons Are Found On The Nfs Server? 

• Nfsd
• Mounted
• Locked
• Statd
• Nfs Lockd

 These five daemons will be in NFS server. Statd and locked will be in NFS client too.
 

33) How Do We Know How Many Lan Cards We Have In Server? 

Just Type in the following command at prompt#ifconfig -a. That shall give the LAN Cards as well as total Physical and Logical IP Addresses

dmesg – It displays all configured items on systems.
 

34) How Can I Disable Stop+a Utility On Sun Machines, Which Brings System Into Ok> Prompt? 

in /etc/system set abort enable=0 will disable STOP-A 

There are several ways to disable “STOP-A”

·      Edit the /etc/default/kbd file KEYBOARD ABORT=disabled.

·      Use the “kbd -a disable” command.

·      Edit /etc/system file set abort enable = 0.
 

35) Consider The Following Crontab Entry: ?59 23 13 * 5 /wipe. Disk? What Time Will This Cronjob Run? 

That means: on Black Friday, your hard drive will get wiped out.

==> (on 13th and Friday) 23:59, /wipe. disk will be running If the 13’Th Day of the month is Friday, the job will run. (week day starts from Sunday day 1).
 

36) What Is The Command To Do An Interactive Boot From The Ok Prompt? 

The Interactive Boot Process:

At the ok prompt, type boot -a and press Enter. The boot program prompts you interactively.

After Power on,

Press,

STOP+A

At the ok prompt type,

Ok>boot –a

 
37) What All Does The Nvram Store? 

Ethernet Address / Host ID / Time of Day (TOD) clock and EEPROM Parameters.
 

38) Where Are All The Port Numbers Stored? 

Port numbers are stored in /etc/services.
 

39) Controlling The Tape Drive? 

Mt –f /dev/rmt/0n à ‘n’ indicates no rewind.

 
40) What Are The Network Utilities? 

·      Snoop a To capture network packets & display contents.

·      Netstat –i à Displays state of Ethernet address.

·      Ndd command à Set & examine kernel parameters namely TCP/IP drivers.