- 1) How does the Solaris operating system boot? …
- 2) Can you explain each of the phases involved in booting the operating system? …
- 3) What to use to use ‘top’ command on Solaris operating system? …
- 4) What do you understand by Solaris?
How do you replace a failed boot disk under meta in solaris? Step by step explanation?
metadb -d c1t0d0s7to scan for the newly added disk.Devfsadm prtvtoc /dev/rdsk/c1t0d0s2 | fmthard -s – /dev/rdsk/c1t1d0s2 fmthard: New volume table of contents now in place. installboot /usr/platform/sun4u/lib/fs/ufs/bootblk /dev/rdsk/c1t1d0s0 metadb -afc 3 c1t0d0s7 metadevadm -u c1t0d0 metattach [mirror] [submirror] # metattach d10 d11# metattach d0 d1 # metareplace -e d0 c1t0d0s0 d0: device c1t0d0s0 is enabled# metareplace -e d10 c1t0d0s1 d10: device c1t0d0s1 is enabled /sbin/installgrub /boot/grub/stage1 /boot/grub/stage2 /dev/rdsk/c1t0d0s0 GRUB:GRUB is the reference implementation of the Free Software Foundation’s Multi boot Specification, which provides a user the choice to boot one of multiple operating systems installed on a computer or select a specific kernel configuration available on a particular operating system’s partitions.
Ans: We use metareplace usually when we have have faulty submirrors and once replaced it resyncs with the failed components. 1) Find the meta state databases on the slice #metadb -i 2) If any meta state databases exist remove them #metadb –d c0t0d0sX where x is slice number 3) Once the meta state databases are removed we can use cfgadm to unconfigure the device #cfgadm -c unconfigure diskname Once unconfigured replace the disk and configure it as below 4)#cfgadm –c configure diskname 5) Now copy the Volume Table Of Contents (VTOC) to the new disk #prtvtoc /dev/rdsk/devicename | fmthard -s – /dev/rdsk/devicename 6) Once the VTOC is in place now use metareplace command to replace the faulty meta devices #metareplace -e d11 devicename ( Where d11 is the meta device ) …………………………………………………..
Ans: A state database is the collections of multiple, replicated database copies and each copy is considered as a state database replica. If the solaris box loses a state database replica, SVM should figure out which state database replicas still contain valid data and boot using the valid ones and this is achieved by using “majority consensus algorithm” and according to this algorithm we need half+1 number of state database replicas before it finds for a valid data. And for the above reason we need to recreate at least three state database replicas when we setup a disk configuration. If all the three database replicas are corrupted meaning we lose all data stored on svm volumes. Hence its good to create as many replicas on separate drives across controllers. ………………………………………………….
Ans: 1) Disks failures (Boot device failures) 2) Insufficient state database replicas issues 3) Wrong entries in /etc/vfstab file ………………………………………………….
6. You have a boot disk under svm, the machine fails to boot and remains in ok prompt? what could be the possible reason?
Ans: 1) May be issue with /etc/system file 2) Root file system corrupted 3) Wrong entries in /etc/vfstab file ………………………………………………….
7. Metastat -p shows a metavolume needs replacement. Metavolume is a single way mirror only. Actually you find disk and metavolumes are ok and I/O is happening to the file systems… how will you remove the metareplace message that comes out of metastat. Ans: Do a two way mirror and check the metastat –p. ( If you still see that message detach and attach the disk using metadetach ) ………………………………………………….
Ans: Creating shared dg form the existing dg’s 1) List all the dg available: #vxdg list 2) Find out the node that is master or slave using: #vxdctl -c mode 3) Deport the disk groups to be shared: #vxdg deport
Ans: Private Region: It has meta data regarding the disk. A copy of the configuration database is copied to each private region with the disk group. It keeps 5 copies of the configuration database. It is configured as slice 3. Once the private region is created it cannot be changed. Public region: This is the area where all users’ data is stored. Usually it is configured as slice 4. …………………………………………………..
10. What would you do if the private region of a particular disk group is full? What are the design considerations for the size of private region in Vxvm disk group?
Ans: Reinitialize the disk with new private region length #vxdisksetup -I c1t0d0 privlen=2048 %Default 1024 …………………………………………………..
12. How would you convert a volume from gen to fsgen? why should you do that?
Ans: 1) #vxprint -g dgname -rhmvps filename > filename.vxoutput 2) open the file simplevol.vxout using your fav editor and change the use_type field alone from gen to fsgen. 3. Save the file. make sure you edit the use_type field alone… 4. Umount the filesystem; umount /simplevol 5. stop the volume ; vxvol -g dgname stop simplevol 6. remove the volume ; vxedit -g dgname -rf rm simplevol 7. using vxmake rebuild the volume from the saved file ; vxmake -g dgname -d simplevol.vxout 8. check the vxprint out; vxprint -g dgname -hrt ; check for the usage type; it would be fsgen 9. start the volume; vxvol -g dgname start simplevol 10. do a fsck for the volume; fsck – y /dev/vx/rdsk/dgname/simplevol 11. mount the filesystem ; mount /simplevol gen assumes a volume does not contain filesystem and fsgen assumes a volume contains a file system. Vxassist uses fsgen as default type and vxmake uses gen as default type. …………………………………………………..
13. How can you unencapsulate a boot disk in VxVM? Ans: http://www.brandonhutchinson.com/Unencapsulating_a_root_disk .html …………………………………………………..
Ans: vxdmp: The way the load balancing done is using round robin approach EMC Power path: It does it by knowing which path is least loaded. Powerpath will fail back a path once it becomes available. The older version of DMP that we were using on Solaris you had to manually bring back the other path. This could have just been the limitations of Solaris as well. We ran Power path on AIX and DMP on SUN. …………………………………………………..
16. vxdisk -o alldgs list o/p shows some disk groups in braces… What does that signify?
Ans: 1) Mirroring (RAID-1) 2) Striping (RAID-0) 3) Concatenation and Spanning 4) Striping plus Mirroring (Mirrored-stripe or RAID 0+1) 5) Mirroring plus Striping (Striped mirror, RAID 1+0, OR RAID-10) 6) RAID-5 (Striping with parity). ……………………………………………………
Ans: Using vxmake we need to build each object until we create a volume and its very easy to use vxassist instead vxmake. 1) Create subdisk ( # vxmake –g dg dgname sd sdname ) 2) Create plex (#vxmake –g dgname plex sd=sdname ) 3) Create volume (#vxmake –g dgname -U fsgen vol plex=plexname ) …………………………………………………..
Ans: With DRL : #vxassist –g
Ans: First check how much space you can increase using #vxassist -g
1) It shows read/write errors in /var/adm/messages. 2) As the time passes we can see increased number of hard and transport error when checkd by iostat -En. 3)We can see the disk available when format is used
Failed disk 1)It shows “ disk not responding to selection” message 2)It only shows the increased transport errors 3)Format command displays “ disk not available” message …………………………………………………..
Ans: Can be removed using vxdiskadm and select option 5 ( To replace a failed disk) 23. Plex is in a disabled state. How will you recover? what are the steps to follow? Ans: 1) Place the plex in CLEAN state #vxmend -g dg fix clean fix 2) To recover other plexes in a volume from CLEAN plex #vxmend -g dg fix stale plex 3) Enable CLEAN plex # vxvol -g dg start volume …………………………………………………..
Ans: Source: Symantec Docs Detach State Detaching a plex leaves the plex associated with its volume, but prevents normal volume I/O from being directed to the plex. This operation can be applied to plexes that are enabled or disabled. The rules for performing the detach depend upon the usage types of the volumes involved. The operation does not apply to dissociated plexes.
Disassociate State Dissociate each of the named plexes. Dissociating a plex breaks the link between the plex and its volume. A dissociated plex is inaccessible until it is reassociated, which can be done either with vxplex att or with vxmake. Any checks and synchronizations that apply to the det operation also apply to the dis operation. Plex dissociation is the normal means of unmirroring a volume, or reducing the mirror count for a volume. To support this use, -o rm can be used to dissociate and remove the plex (and its associated subdisks) in the same operation. This makes the space used by those subdisks usable for new allocations (such as with vxassist or with vxmake).
Plex dissociation can also be used for file system backups of volumes that are normally mirrored. Plex devices are not directly mountable, so the backup method described for the det operation will not work if the backup program requires a mounted file system. To support such backup programs, a plex can be dissociated and can then be allocated to a new volume, such as with the command:
vxmake -U gen vol volume plex=plex The created volume can then be started and mounted for use by the backup program. …………………………………………………..
Ans: During the solaris boot process once it reads the /etc/system file and is supposed to boot from veritas volumes below are the two lines that need to be placed in /etc/system file such that it boot using veritas root device. 1. rootdev:/pseudo/vxio@0:0 2. set vxio_vol_rootdev_is_volume=1 …………………………………………………..
26. What’s the difference between SVM and VxVM? What would you recommend to your clients? why?
1) Third party software where we need to install it 2) We can shrink volume in VxVM ……………………………………………………
Ans: Never worked on all but can give below answer if you have worked on any of them: 1) Sun Cluster 2) Veritas cluster 3) HACMP – High Availability Cluster Multiprocesing …………………………………………………..
Ans: Depends on the taste of the guy and budget they have to implement the cluster. ……………………………………………………
1) Kernel-based – Fatser in failure detection 2) It runs only on Solaris systems ( Platform dependent)
Ans: To start an agent: #haagent – start agentname -sys To start cluster : #hastart Configuration file: /etc/VRTSvcs/conf/config/main.cf …………………………………………………..
Ans: The situation when two or more clusters cannot communicate with each other and each node thinks that it owns the resources is said to be split brain scenario.
Shortcuts are created using “links” on Linux. There are two types of links that can be used namely “soft link” and “hard link”
Soft links are link to the file name and can reside on different filesytem as well; however hard links are link to the inode of the file and has to be on the same filesytem as that of the file. Deleting the orginal file makes the soft link inactive (broken link) but does not affect the hard link (Hard link will still access a copy of the file)
$@ treats each quoted arguments as separate arguments but $* will consider the entire set of positional parameters as a single string.
T – Stopped, either by a job control signal or because it is being traced
Private pages which are not shared with any other processes (NB: private pages can STILL be copy-on-write!) must count even if swapped out
Shared pages should count divided by the number of processes they’re shared by e.g. a page shared by two processes counts half
If the same page is mapped more than once into the address-space of the same process, it can be ignored the 2nd and subsequent time. This means that if proc 1 has page X mapped twice, and proc 2 has page X mapped once, they are both “charged” half a page.
We also have to decide whether we want to include the time from children processes. If we do, then we add those values to total_time:
Memory Usage = (number of pages the application has in RAM) * (page size) / (total available RAM)
CPU Load = (system + user + nice + iowait + irq + softirq)/ (user + nice + system + idle + iowait + irq + softirq)
egrep is Extended grep that supports added grep features like “+” (1 or more occurrence of previous character),”?”(0 or 1 occurrence of previous character) and “|” (alternate matching)
A swap space is a certain amount of space used by Linux to temporarily hold some programs that are running concurrently. This happens when RAM does not have enough memory to hold all programs that are executing.
While going through the list of processes I saw a long list of deleted files which were still occupied by the PID.
Q: – What server need to check first – physical memory is not fully utilized but swap is fully utilized and physical memory is fully utilized but swap memory is free and why ?
Q: – How Can we check the front & back ports on emc storage server through command line or gui ?
Ans: LVM stands for Logical Volume Manager , to resize filesystem’s size online we required LVM partition in Linux. Size of LVM partition can be extended and reduced using the lvextend & lvreduce commands respectively.
Ans: Using ‘free’ & ‘vmstat’ command we can display the physical and virtual memory statistics respectively.With the help of ‘sar’ command we see the CPU utilization & other stats.
Ans: Sar Collect, report, or save system activity information. The default version of the sar command (CPU utilization report) might be one of the first facilities the user runs to begin system activity investigation, because it monitors major system resources. If CPU utilization is near 100 percent (user + nice + system), the workload sampled is CPU-bound.
By default log files of Sar command is located at /var/log/sa/sadd file, where the dd parameter indicates the current day.
– Use the lvextend command (lvextend -L +100M /dev/
Ans: Using fdisk utility we can create partitions from the raw disk.Below are the steps to create partition from the raw dsik :
– After creating partition , type w command to write the changes to the partition table.
Ans: The ‘/lib/modules/kernel-version/’ directory stores all kernel modules or compiled drivers in Linux operating system. Also with ‘lsmod’ command we can see all the installed kernel modules.
Ans: umask stands for ‘User file creation mask’, which determines the settings of a mask that controls which file permissions are set for files and directories when they are created.
Ans: To set this value permanently for a user, it has to be put in the appropriate profile file which depends on the default shell of the user.
Ans: To change the run level we have to edit the file “/etc/inittab” and change initdefault entry ( id:5:initdefault:). Using ‘init’ command we change the run level temporary like ‘init 3′ , this command will move the system in runlevl 3.
Ans: To share a directory using nfs , first edit the configuration file ‘/etc/exportfs’ , add a entry like
Ans: Using ‘showmount’ command we can see what directories are shared via nfs e.g ‘showmount -e
Ans: Network bonding is the aggregation of multiple Lan cards into a single bonded interface to provide fault tolerance and high performance. Network bonding is also known as NIC Teaming.
Ans: Using the command ‘cat /proc/net/bonding/bond0′ , we can check which mode is enabled and what lan cards are used in this bond. In this example we have one only one bond interface but we can have multiple bond interface like bond1,bond2 and so on.
Ans: Using the Commands ‘netstat -nr’ and ‘route -n’ we can see the default route and routing tables.
Q:19 List the services that are enabled at a particular run level in linux server ?
Ans: With the help of command ‘chkconfig –list | grep 5:on’ we can list all the service that are enabled in run level5. For other run levels just replace 5 with the respective run level.
Ans: We should never upgrade Linux Kernel , always install the new New kernel using rpm command because upgrading a kenel can make your linux box in a unbootable state.
Ans: We can find the WWN numbers of HBA cards using the command ‘systool -c fc_host -v | grep port_name’
Ans: To Set the kernel parameters in linux , first edit the file ‘/etc/sysctl.conf’ after making the changes save the file and run the command ‘sysctl -p’ , this command will make the changes permanently without rebooting the machine.
Ans: Puppet is an open-source & enterprise software for configuration management toll in UNIX like operating system. Puppet is a IT automation software used to push configuration to its clients (puppet agents) using code. Puppet code can do a variety of tasks from installing new software, to check file permissions, or updating user accounts & lots of other tasks.
Ans: Load Average is defined as the average sum of the number of process waiting in the run queue and number of process currently executing over the period of 1,5 and 15 minutes. Using the ‘top’ and ‘uptime’ command we find the load average of a linux sever.
Open source allows you to distribute your software, including source codes freely to anyone who is interested. People would then be able to add features and even debug and correct errors that are in the source code. They can even make it run better, and then redistribute these enhanced source code freely again. This eventually benefits everyone in the community.
Just like any other typical operating system, Linux has all of these components: kernel, shells and GUIs, system utilities, and application program. What makes Linux advantageous over other operating system is that every aspect comes with additional features and all codes for these are downloadable for free.
In general, one desktop environment, like KDE or Gnome, is good enough to operate without issues. It’s all a matter of preference for the user, although the system allows switching from one environment to another. Some programs will work on one environment and not work on the other, so it could also be considered a factor in selecting which environment to use.
– under BASH, / character is a directory separator and ‘ acts as an escape character. Under DOS, / serves as a command argument delimiter and ‘ is the directory separator
– DOS follows a convention in naming files, which is 8 character file name followed by a dot and 3 character for the extension. BASH follows no such convention.
This so-called Free software movement allows several advantages, such as the freedom to run programs for any purpose and freedom to study and modify a program to your needs. It also allows you to redistribute copies of a software to other people, as well as freedom to improve software and have it released to the public.
The root account is like a systems administrator account, and allows you full control of the system. Here you can create and maintain user accounts, assigning different permissions for each account. It is the default account every time you install Linux.
CLI is short for Command Line Interface. This interface allows user to type declarative commands to instruct the computer to perform operations. CLI offers an advantage in that there is greater flexibility. However, other users who are already accustom with using GUI find it difficult to remember commands including attributes that come with it.
GUI, or Graphical User Interface, makes use of s and icons that users click and manipulate as a way of communicating with the computer. Instead of having to remember and type commands, the use of graphical elements makes it easier to interact with the system, as well as adding more attraction through s, icons and colors.
To open the default shell (which is where the command prompt can be found), press Ctrl-Alt-F1. This will provide a command line interface (CLI) from which you can run commands as needed.
From a command shell, use the “concatenate” command: cat /proc/meminfo for memory usage information. You should see a line starting something like: Mem: 64655360, etc. This is the total memory Linux thinks it has available to use.
The preferred size for a swap partition is twice the amount of physical memory available on the system. If this is not possible, then the minimum size should be the same as the amount of memory installed.
Symbolic links act similarly to shortcuts in Windows. Such links point to programs, files or directories. It also allows you instant access to it without having to go directly to the entire pathname.
Yes, it does. Just like Windows, you can use this key combination to perform a system restart. One difference is that you won’t be getting any confirmation message and therefore, reboot is immediate.
20) How do you refer to the parallel port where devices such as printers are connected?
Whereas under Windows you refer to the parallel port as the LPT port, under Linux you refer to it as /dev/lp . LPT1, LPT2 and LPT3 would therefore be referred to as /dev/lp0, /dev/lp1, or /dev/lp2 under Linux.
No. In Linux, each drive and device has different designations. For example, floppy drives are referred to as /dev/fd0 and /dev/fd1. IDE/EIDE hard drives are referred to as /dev/hda, /dev/hdb, /dev/hdc, and so forth.
Assuming you are the system administrator or the owner of a file or directory, you can grant permission using the chmod command. Use + symbol to add permission or – symbol to deny permission, along with any of the following letters: u (user), g (group), o (others), a (all), r (read), w (write) and x (execute). For example the command chmod go+rw FILE1.TXT grants read and write access to the file FILE1.TXT, which is assigned to groups and others.
Serial ports are identified as /dev/ttyS0 to /dev/ttyS7. These are the equivalent names of COM1 to COM8 in Windows.
Linux assigns numbers at the end of the drive identifier. For example, if the first IDE hard drive had three primary partitions, they would be named/numbered, /dev/hda1, /dev/hda2 and /dev/hda3.
Hard links point directly to the physical file on disk, and not on the path name. This means that if you rename or move the original file, the link will not break, since the link is for the file itself, not the path where the file is located.
Any filename can have a maximum of 255 characters. This limit does not include the path name, so therefore the entire pathname and filename could well exceed 255 characters.
In general, filenames that are preceded by a dot are hidden files. These files can be configuration files that hold important data or setup info. Setting these files as hidden makes it less likely to be accidentally deleted.
This serves as an alternative to minimizing and maximizing different windows on the current desktop. Using virtual desktops, each desktop is a clean slate where you can open one or more programs. Rather than minimizing/restoring all those programs as needed, you can simply shuffle between virtual desktops with programs intact in each one.
To share a program across different virtual desktops, in the upper left-hand corner of a program window look for an icon that looks like a pushpin. Pressing this button will “pin” that application in place, making it appear in all virtual desktops, in the same position onscreen.
This empty directory name serves as the nameless base of the Linux file system. This serves as an attachment for all other directories, files, drives and devices.
The pwd command is short for print working directory command. It’s counterpart in DOS is the cd command, and is used to display the current location in the directory tree.
Daemons are services that provide several functions that may not be available under the base operating system. Its main task is to listen for service request and at the same time to act on these requests. After the service is done, it is then disconnected and waits for further requests.
33) How do you switch from one desktop environment to another, such as switching from KDE to Gnome?
Assuming you have these two environments installed, just log out from the graphical interface. Then at the Log in screen, type your login ID and password and choose which session type you wish to load. This choice will remain your default until you change it to something else.
When we talk about case sensitivity, commands are considered identical only if every character is encoded as is, including lowercase and uppercase letters. This means that CD, cd and Cd are three different commands. Entering a command using uppercase letters, where it should be in lowercase, will produce different outputs.
Environmental variables are global settings that control the shell’s function as well as that of other Linux programs. Another common term for environmental variables is global shell variables.
– Ex mode – this is the mode wherein you interact with vi with instructions to process a file
Yes, there is. A feature known as filename expansion allows you do this using the TAB key. For example, if you have a path named /home/iceman/assignments directory, you would type as follows: /ho[tab]/ice[tab]/assi[tab] . This, however, assumes that the path is unique, and that the shell you’re using supports this feature.
Redirection is the process of directing data from one output to another. It can also be used to direct an output as an input to another process.
grep a search command that makes use of pattern-based searching. It makes use of options and parameters that is specified along the command line and applies this pattern into searching the required file output.
41) What could possibly be the problem when a command that was issued gave a different result from the last time it was used?
One highly possible reason for getting different results from what seems to be the same command has something to do with case sensitivity issues. Since Linux is case sensitive, a command that was previously used might have been entered in a different format from the present one. For example, to lists all files in the directory, you should type the command ls, and not LS. Typing LS would either result in an error message if there is no program by that exact name exist, or may produce a different output if there is a program named LS that performs another function.
It contains locally installed files. This directory actually matters in environments where files are stored on the network. Specifically, locally-installed files go to /usr/local/bin, /usr/local/lib, etc.). Another application of this directory is that it is used for software packages installed from source, or software not officially shipped with the distribution.
Every process in the system is identified by a unique process id or pid. Use the kill command followed by the pid in order to terminate that process. To terminate all process at once, use kill 0.
Comments are created by typing the # symbol before the actual comment text. This tells the shell to completely ignore what follows. For example: “# This is just a comment that the shell will ignore.”
You can use parentheses to group commands. For example, if you want to send the current date and time along with the contents of a file named OUTPUT to a second file named MYDATES, you can apply command grouping as follows: (date cat OUTPUT) > MYDATES
46) How do you execute more than one command or program from a single command line entry?
You can combine several commands by separating each command or program using a semicolon symbol. For example, you can issue such a series of commands in a single entry:
1 ls –l cd .. ls –a MYWORK which is equivalent to 3 commands: ls -l cd.. ls -a MYWORK
47) Write a command that will look for files with an extension “c”, and has the occurrence of the string “apple” in it.
-use the result and use a grep command to search for all occurrences of the word ORANGE in the files.
(:- Here interviewers will try to screw you by asking the cluster setup.The next question will be …
We have configured the failover service group and added the zone as resource.zones are installed on shared storage and LUNS are visible on both the cluster nodes.If there is any issue on one global zone ,the service group will automatically fail-overs to second global zone.In other words, zone will be halted on one node and booted in other node.
This kind of cluster setup is very less compare to the traditional & complex start/stop scripts for application.
Off-course without having the hands on experience ,it is hard to explain with confidence.So Practice the VCS cluster yourself before attending any interviews.
There are three article in Unixarena to get the setup to be done on VMWARE workstation to practice yourself.
The same trick you can follow on the Linux interview as well. Redhat Cluster as well supports the virtual machine failover. If the interviewer ask about the redhat cluster, you simply say that ” I am working two node redhat cluster – virtual machine failover setup”.
Redhat cluster has been installed on both the cluster nodes and configured as two node cluster.We have KVM packages installed and configured with the virtual guests on both the nodes.Those virtual guests aka virtual servers have added in to the redhat cluster as resource and if there is any issues with one server, all the virtual machine will be halted/killed and those will be booted on the second cluster node.
The beauty of redhat cluster + KVM is that virtual machines can be failover to other node without hating/rebooting it .
I am sure that if you explain these setup with confidence, definitely interviewer will not ask further question on this.
It is a program that allows multiple operating systems to share a single hardware host. Each operating system appears to have the host’s processor, memory, and other resources all to itself. However, the hypervisor is actually controlling the host processor and resources, allocating what is needed to each operating system in turn and making sure that the guest operating systems (called virtual machines) cannot disrupt each other.
Below is the table showing the different version of hardware used in different VMware products along with their release version
VMware ESX and ESXi are both bare metal hypervisor architectures that install directly on the server hardware.
Although neither hypervisor architectures relies on an OS for resource management, the vSphere ESX architecture relied on a Linux operating system, called the Console OS (COS) or service console, to perform two management functions: executing scripts and installing third-party agents for hardware monitoring, backup or systems management.
In the vSphere ESXi architecture, the service console has been removed. The smaller code base of vSphere ESXi represents a smaller “attack surface” and less code to patch, improving reliability and security.
This isn’t the file containing the raw data. Instead it is the disk descriptor file which describes the size and geometry of the virtual disk file. This file is in text format and contains the name of the –flat.vmdk file for which it is associated with and also the hard drive adapter type, drive sectors, heads and cylinders, etc. One of these files will exist for each virtual hard drive that is assigned to your virtual machine. You can tell which –flat.vmdk file it is associated with by opening the file and looking at the Extent Description field.
Server Virtualization – consolidating multiple physical servers into virtual servers that run on a single physical server.
Application Virtualization – an application runs on another host from where it is installed in a variety of ways. It could be done by application streaming, desktop virtualization or VDI, or a VM package (like VMware ACE creates with a player). Microsoft Softgrid is an example of Application virtualization.
Presentation Virtualization – This is what Citrix Met frame (and the ICA protocol) as well as Microsoft Terminal Services (and RDP) are able to create. With presentation virtualization, an application actually runs on another host and all that you see on the client is the screen from where it is run.
Network Virtualization – with network virtualization, the network is “carved up” and can be used for multiple purposes such as running a protocol analyzer inside an Ethernet switch. Components of a virtual network could include NICs, switches, VLANs, network storage devices, virtual network containers, and network media.
Storage Virtualization – with storage virtualization, the disk/data storage for your data is consolidated to and managed by a virtual storage system. The servers connected to the storage system aren’t aware of where the data really is. Storage virtualization is sometimes described as “abstracting the logical storage from the physical storage.
VMware VMotion enables the live migration of running virtual machines from one physical server to another with zero downtime.
o vMotion migrates the vm from one host to another which is only possible with both the host are sharing a common storage or to any storage accessible by both the source and target hosts.
o A shared storage can be on a Fibre Channel storage area network (SAN), or can be implemented using iSCSI SAN and NAS.
o If you use vMotion to migrate virtual machines with raw device mapping (RDM) files, make sure to maintain consistent LUN IDs for RDMs across all participating hosts.
o Use at least one 10 GigE adapter if you migrate workloads that have many memory operations.
o Ensure that jumbo frames are enabled on all network devices that are on the vMotion path including physical NICs, physical switches and virtual switches.
A snapshot is a “point in time ” of a virtual guest operating system (VM). That snapshot contains an of the VMs disk, RAM, and devices at the time the snapshot was taken. With the snapshot, you can return the VM to that point in time, whenever you choose. You can take snapshots of your VMs, no matter what guest OS you have and the snapshot functionality can be used for features like performing level backups of the VMs without ever shutting them down.
NOTE: Using HA in case of any host failure with RESTART the vms on different host so the vms state will be interrupted and it is not a live migration
VMware HA is used in the event when any of the hosts inside a cluster fails then all the virtual machines running under it are restarted on different host in the same cluster.
Now HA is completely dependent on vMotion to migrate the vms to different host so vMotion is just used for the migration purpose between multiple hosts. vMotion also has the capability to migrate any vm without interrupting its state to any of the host inside cluster.
You can place the original (or Primary virtual machine). You have full control with DRS or vMotion to assign it to any node. The placement of the Secondary, when created, is automatic based on the available hosts. But when the Secondary is created and placed, you can vMotion it to the preferred host.
When Fault Tolerance is configured for a virtual machine, vCenter Server need not be online for FT to work. Even if vCenter Server is offline, failover still occurs from the Primary to the Secondary virtual machine. Additionally, the spawning of a new Secondary virtual machine also occurs without vCenter Server.
When we configure multiple hosts for HA cluster, a single host is automatically elected as the master host. The master host communicates with vCenter Server and monitors the state of all protected virtual machines and of the slave hosts. When you add a host to a vSphere HA cluster, an agent is uploaded to the host and configured to communicate with other agents in the cluster.
When vSphere HA is enabled for a cluster, all active hosts (those not in standby or maintenance mode, or not disconnected) participate in an election to choose the cluster’s master host. The host that mounts the greatest number of datastores has an advantage in the election. Only one master host typically exists per cluster and all other hosts are slave hosts.
If the master host fails, is shut down or put in standby mode, or is removed from the cluster a new election is held.
vSphere HA is not dependent on vCenterserver for its operations as when HA is configured it installs an agent into each host which does its part and is not dependent on vCenterserver. Also HA doesnot uses vMotion, it justs restarts the vms into another host in any case of host failure.
Further vSphere DRS is very much dependent on vCenterserver as it uses vMotion for its action for live migration of vms between multiple hosts so in case vCenterserver goes down the vMotion won’t work leading to failure of DRS.
VMware Tools is a suite of utilities that enhances the performance of the virtual machine’s guest operating system and improves management of the virtual machine. Without VMware Tools installed in your guest operating system, guest performance lacks important functionality. Installing VMware Tools eliminates or improves these issues:
SOLARIS 10 Admin Interview Questions and Answers for Both Fresher & Experience
What is the command to do an interactive boot from the ok prompt?
After Power on, press, STOP+A at the ok prompt type:
How can u check parameters in ok boot prompt?
To check parameter on the OK prompt:
Oracle Solaris is a proprietary Unix operating system originally developed by Sun Microsystems earlier SunOS in 1993. In 2010, after the Sun acquisition by Oracle, it was renamed Oracle Solaris. Solaris is known for its scalability, especially on SPARC systems, and for originating many innovative features such as DTrace, ZFS and Time Slider. Solaris supports SPARC and x86-64 workstations and servers from Oracle and other vendors.
How to Formating a disk in solaris?
– add the disk, run devfsadm command. – then format command > select disk, enter the required details for formating. – create a new partition table using the format command. – then create a new file system on it using:
– then put its entry in /etc/vfstab.
FAQ
What is Solaris used for?
What kind of operating system is Oracle Sparc Solaris?
What is Solaris administrator?
