1z0-821 Oracle Solaris 11 System Administration Questions and Answers

'ipadm show-addr' displays all the configured addresses on the system.

Example:

# ipadm show-addr

ADDROBJ TYPE STATE ADDR

lo0/v4 static ok 127.0.0.1/8

lo0/v6 static ok ::1/128

Use the chmod command to change permissions for a file or directory. You must be the owner of a file or directory, or have root access, to change its permissions.

Here we do not know if brian owns db_data.

Note:

Permission

7 full

6 read and write

5 read and execute

4 read only

3 write and execute

2 write only

1 execute only

0 none

0 --- no permission

1 --x execute

2 -w- write

3 -wx write and execute

4 r-- read

5 r-x read and execute

6 rw- read and write

7 rwx read, write and execut

Solaris: Solaris Advanced User's Guide

If you are assigning a static IP address, use the following syntax:

# ipadm create-addr -T static -a address addrobj

where addrobj uses the naming format interface/user-defined-string, such as e1000g0/v4globalz.

Note:

create-addr [-t] -T static [-d] -a {local | remote}=addr[/prefixlen], ... addrobj

Creates a static IPv4 or IPv6 address on the interface specified in addrobj. If the interface on which the address is created is not plumbed, this subcommand will implicitly plumb the interface. The created static address will be identified by addrobj.

By default, a configured address will be marked up, so that it can be used as a source or destination of or for outbound and inbound packets.

IP address and name service (such as a DNS server) are provided by the DHCP server.

The first IP address is already in use.

Show address information, either for the given addrobj or all the address objects configured on the specified interface, including the address objects that are only in the persistent configuration.

State can be: disabled, down, duplicate, inaccessible, ok, tentative

Example:

# ipadm show-addr

ADDROBJ TYPE STATE ADDR

lo0/v4 static ok 127.0.0.1/8

lo0/v6 static ok ::1/128

tail is a program on Unix and Unix-like systems used to display the last few lines of a text file or piped data.

By default, tail will print the last 10 lines of its input to the standard output. With command line options the number of lines printed and the printing units (lines, blocks or bytes) may be changed. The following example shows the last 20 lines of filename:

tail -n 20 filename

pkgchk checks the accuracy of installed files or, by using the -l option, displays information about package files. pkgchk checks the integrity of directory structures and files. Discrepancies are written to standard error along with a detailed explanation of the problem.

ZFS Deduplication Property

Solaris Express Community Edition, build 129: In this Solaris release, you can use the deduplication property to remove redundant data from your ZFS file systems. If a file system has the dedup property enabled, duplicate data blocks are removed synchronously. The result is that only unique data is stored and common components are shared between files.

You can enable this property as follows:

# zfs set dedup=on tank/home

zfs snapshot [-r] [-o property=value] ... filesystem@snapname|volume@snapname

Creates a snapshot with the given name. All previous modifications by successful system calls to the file system are part of the snapshot. See the “Snapshots” section for details.

-r

Recursively create snapshots of all descendent datasets. Snapshots are taken atomically, so that all recursive snapshots correspond to the same moment in time.

If the boot environment is unbootable, it is marked with an exclamation point (!) in the Active column in the beadm list output.

The beadm command restricts actions on unbootable boot environments as follows:

You cannot activate an unbootable boot environment. (B)

You cannot destroy a boot environment that is both unbootable and marked as active on reboot.

You cannot create a snapshot of an unbootable boot environment.

You cannot use an unbootable boot environment or boot environment snapshot with the -e option of beadm create.

You cannot rename an unbootable boot environment. (C)

REPOSITORY DESCRIPTION

* http://pkg.oracle.com/solaris/release

The default repository for new Oracle Solaris 11 users. This repository receives updates for each new release of Oracle Solaris. Significant bug fixes, security updates, and new software may be provided at any time for users to install at Oracle's discretion.

*https://pkg.oracle.com/solaris/support

Provides bug fixes and updates. Accessible with a current support contract from Oracle.

* https://pkg.oracle.com/solaris/dev Provides the latest development updates. Accessible to users enrolled in the Oracle Solaris 11 Platinum Customer Program and approved Oracle Partners.

Enable-if -t interface

Enables the given interface by reading the configuration from the persistent store. All the persistent interface properties, if any, are applied and all the persistent addresses, if any, on the given interface will be enabled.

-t, --temporary

Specifies that the enable is temporary and changes apply only to the active configuration.

Oracle Solaris 11 introduces user environment and command-line argument changes that include the following:

* Shell changes - The default shell, /bin/sh, is now linked to ksh93. The default user shell is the Bourne-again (bash) shell.

* The legacy Bourne shell is available as /usr/sunos/bin/sh.

* The legacy ksh88 is available as /usr/sunos/bin/ksh from the shell/ksh88 package.

* Korn shell compatibility information is available in /usr/share/doc/ksh/COMPATIBILITY.

The Internet Protocol (IP) is the principal communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.

No OpenBoot Environment on the Intel Platform. The Intel environment has no OpenBoot PROM or NVRAM. On Intel systems, before the kernel is started, the system is controlled by the basic input/output system (BIOS), the firmware interface on a PC. Therefore, many features provided by OpenBoot are not available on Intel systems.

Note: The Open Boot PROM (OBP) bootloader only exists within SPARC. Before Solaris 10 01/06, the bootloader for Solaris x86 was a Sun customized bootstrap software. After Solaris 10 01/06, it uses GRUB, a well known bootloader that's commonly used in the Linux world.

With GRUB, it's much easier to make the system dual-boot Linux and Solaris. GRUB extends the capabilities of the bootloader that was not available previously such as the ability to boot from a USB DVD drive. Those who have used Linux will be quite familiar with GRUB and its options.

If you're logged on to the system, you can run prstat -Z to generate a summary of cpu/memory utilization by zone.

If a command is terminated by the control operator ‘&’, the shell executes the command asynchronously in a subshell. This is known as executing the command in the background. The shell does not wait for the command to finish, and the return status is 0 (true).

The fingerprints are used to guard against man in the middle attacks. Since ssh logins usually work over the internet (an insecure connection), someone could hijack your connection. When you try to log into yourmachine.com, he could get "in the middle" and return your challenge as if he was yourmachine.com. That way, he could get hold of your login password.

To make this attack harder, ssh stores the fingerprint of the server's public key on the first connection attempt. You will see a prompt like:

The authenticity of host 'eisen (137.43.366.64)' can't be established.

RSA key fingerprint is cf:55:30:31:7f:f0:c4:a0:9a:02:1d:1c:41:cf:63:cf.

Are you sure you want to continue connecting (yes/no)

When you enter yes, ssh will add the fingerprint to your known_hosts file. you will see

Code:

Warning: Permanently added 'eisen, 137.43.366.64' (RSA) to the list of known hosts.

The next time you login, ssh will check whether the host key has changed. A changing host key usually indicates a man in the middle attack, and ssh refuses to connect.

crontab: you are not authorized to use cron. Sorry.

This message means that either the user is not listed in the cron.allow file (if the file exists), or the user is listed in the cron.deny file.

You can control access to the crontab command by using two files in the /etc/cron.d directory: cron.deny and cron.allow. These files permit only specified users to perform crontab command tasks such as creating, editing, displaying, or removing their own crontab files.

The cron.deny and cron.allow files consist of a list of user names, one user name per line.

A kernel panic is a type of error that occurs when the core (kernel) of an operating system receives an instruction in an unexpected format or when it fails to handle properly. A kernel panic can also follow when the operating system can’t recover from a different type of error. A kernel panic can be caused by damaged or incompatible software or, more rarely, damaged or incompatible hardware.

When a server kernel panics it abruptly halts all normal system operations. Usually, a kernel process named panic() outputs an error message to the console and stores debugging information in nonvolitile memory to be written to a crash log file upon restarting the computer. Saving the memory contents of the core and associated debugging information is called a “core dump.”

B: Binary Signatures for Third-Party Software

The elfsign command provides a means to sign providers to be used with the Oracle Solaris Cryptographic Framework. Typically, this command is run by the developer of a provider.

The elfsign command has subcommands to request a certificate from Sun and to sign binaries. Another subcommand verifies the signature. Unsigned binaries cannot be used by the Oracle Solaris Cryptographic Framework. To sign one or more providers requires the certificate from Sun and the private key that was used to request the certificate.

C: Export law in the United States requires that the use of open cryptographic interfaces be restricted. The Oracle Solaris Cryptographic Framework satisfies the current law by requiring that kernel cryptographic providers and PKCS #11 cryptographic providers be signed.

* Updating all of the packages on your installed system – To update all of the packages on your system that have available updates, use the pkg update command, as follows:

# pkg update

Running this command updates packages that you might not otherwise consider updating, for example, kernel components and other low-level system packages.

* Adding or updating individual packages – To add individual software packages, use the pkg install command. Any dependent packages are also updated at the same time.

* install package updates that deliver fixes– A pkg update operation might include bug fixes, so the operation is similar to applying a specific patch or patches in previous Oracle Solaris releases.

Note: The IPS interfaces first check for updates for currently installed packages before retrieving them via the network. By default, interfaces check repository catalogs in the following locations:

* The default installation repository at pkg.oracle.com/solaris/release.

* The support repository in My Oracle Support. This repository is restricted to users with Oracle Solaris 11 Express support contracts, and it contains packages with the latest bug fixes. For this reason, a support contract must be purchased for production deployments.

A ZFS reservation is an allocation of disk space from the pool that is guaranteed to be available to a dataset. As such, you cannot reserve disk space for a dataset if that space is not currently available in the pool. The total amount of all outstanding, unconsumed reservations cannot exceed the amount of unused disk space in the pool. ZFS reservations can be set and displayed by using the zfs set and zfs get commands. For example:

# zfs set reservation=5G tank/home/bill

# zfs get reservation tank/home/bill

NAME PROPERTY VALUE SOURCE

tank/home/bill reservation 5G local

* The whoami utility displays your effective user ID as a name.

Here this would be root.

* who am i

The command who shows who is logged on.

Here this would be:

user1 console Dec 30 20:20

* The id utility displays the user and group names and numeric IDs, of the calling process, to the standard output. If the real and effective IDs are different, both are displayed, otherwise only the real ID is displayed.

Here this would be:

uid=0(root) gid=0(root)

Note:

Each UNIX proces has 3 UIDs associated to it. Superuser privilege is UID=0.

Real UID

--------

This is the UID of the user/process that created THIS process. It can be changed only if the running process has EUID=0.

Effective UID

-------------

This UID is used to evaluate privileges of the process to perform a particular action. EUID can be change either to RUID, or SUID if EUID!=0. If EUID=0, it can be changed to anything.

Saved UID

---------

If the binary image file, that was launched has a Set-UID bit on, SUID will be the UID of the owner of the file. Otherwise, SUID will be the RUID.

B: It can be created by importing a Solaris 10 flash archive.

You can use the Oracle Solaris Flash archiving tools to create an image of an installed system that can be migrated into a zone.

The system can be fully configured with all of the software that will be run in the zone before the image is created. This image is then used by the installer when the zone is installed.

Note: You can use alternate methods for creating the archive. The installer can accept the following archive formats:

* cpio archives

* gzip compressed cpio archives

* bzip2 compressed cpio archives

* pax archives created with the -x xustar (XUSTAR) format

Ä ufsdump level zero (full) backups

Note:

Branded zones that run an environment different that the OS release on the system

* The lx branded zone introduced in the Solaris 10 8/07 release provides a Linux environment for your applications and runs on x86 and x64 machines on the Oracle Solaris 10 OS.

* The solaris8 and solaris9 branded zones enable you to migrate an Oracle Solaris 8 or Oracle Solaris 9 system to an Oracle Solaris 8 or Oracle Solaris 9 Container on a host running the Oracle Solaris 10 8/07 Operating System or later Oracle Solaris 10 release.

* The Oracle Solaris 10 Container brand is available in OpenSolaris build 127. These branded zones host Oracle Solaris 10 user environments.

Note: One of the powerful features of Solaris 11 is the ability to run a Solaris 10 environment in a zone. Solaris 10 allows you to run Solaris 8 and 9 environments in zones, but only on SPARC.

The line

init core file pattern: /var/core/core.%f.%p

will be used for the non-global process to determine the destination of the dump file.

Note: When a process is dumping core, up to three core files can be produced: one in the per-process location, one in the system-wide global location, and, if the process was running in a local (non-global) zone, one in the global location for the zone in which that process was running.

According to the exhibit the interface already exists.

The command ipadm create-ip net3 is supposed to create a new interface net3.

A subnetwork, or subnet, is a logically visible subdivision of an IP network. The practice of dividing a network into two or more networks is called subnetting.

The routing prefix of an address is written in a form identical to that of the address itself. This is called the network mask, or netmask, of the address. For example, a specification of the most-significant 18 bits of an IPv4 address, 11111111.11111111.11000000.00000000, is written as 255.255.192.0.