Google IT Support Professional Certificate: Operating Systems and you. Week 3
Event Viewer
Windows GUI application to view event logs
Windows: find hidden items
"View" tab, then Hidden items
Default port for SSH
22
archive command in Linux with 7zip
7z -a <filepath> (archive) 7z -e <filepath> (extract)
Echo
Alias for Write-Output
GUI
Graphical User Interface
Get-Package
This command allows an administrator to view a list of all software packages that have been installed by using Package Management
how to view user and group information in Windows
Through the Computer Management tool. OR Get-LocalUser, Get-LocalGroup, Get-LocalGroupMember
What's the purpose of a DLL in Windows?
To share a package of useful code among programs; A DLL, or Dynamic Linked Library, is loaded when a program is run, and provides useful code for the program.
Modify permission in Windows
Umbrella permission that includes read, execute and write
Uninstall-Package -Name <name>
Uninstall package Windows
Full control
can do anything to a document, including everything in modify, plus the ability to take ownership of a file and change its ACLs
cd
change directory in both W and Lx
cd ..
change directory up one level
disk management command from CLI
diskpart
NTFS
file system for Windows
anatomy of Linux file permission 10 bits
first bit - dash means file, d means directory first trio - file owner permissions second trio - group permissions (the group the file belongs to) third trio - everyone else's permission on this file
--help
how to get more info on a topic in Linux
process
program in execution
The "setuid" permission...
* allows a command to be run as the file owner. numerical representation - 4 before the chmod number
The setgid permission...
...allows a command to be run as the group owner of the file. ...allows files created in a directory to be owned by the group that owns the directory. numerical representation is a 2 before the chmod numbers
The "sticky bit" permission...
...prevents others from removing files they don't own from a common directory. added by +t or 1 before numbers. i.e. sudo chmod +t filepath or sudo chmod 1755 filepath
Which of the following file extensions are considered archives in Windows? Check all that apply.
.tar; The .tar, .zip and .rar file extensions are used as archives. The .exe file extension is a Windows executable file. .zip .rar
common archive file types
.zip .tar .rar common tool - 7zip
where is the list of package repositories on Linux?
/etc/apt/sources.list
If you want to automatically mount a filesystem on computer startup, what file do you have to modify?
/etc/fstab; To automatically mount filesystems on startup, you have to add a device entry to the /etc/fstab file.
where to find list of users on a Linux machine
/etc/passwd user info has three parts username password - encrypted user ID
In what log files can you find information about authentication errors?
/var/log/auth.log; The auth.log file contains authentication log messages.
In what log files can you find information about bootup errors? Check all that apply.
/var/log/syslog; You can find log information about bootup issues in kern.log as well as the syslog. /var/log/kern.log
Shell
CLI in Linux
icacls.exe
Cmd line utility to configure NTFS permissions.
CLI
Command Line Interface
how to compress and expand archives in Windows
Compress-Archive -Path <source filepath> <destination filepath> Expand-Archive <target file>
What's the PowerShell commandlet you can use to extract and compress archives right from the commandline?
Compress-Archive; The Compress-Archive commandlet in PowerShell can help you work with Archives from the command line.
cat
Concatenate and print (display) the content of files
If you're performing an installation from the command line in Windows, what's the best method of checking out the options that the installation package provides? Check all that apply.
Consult the documentation for the application to see what options they provide; Often the /?, /h and /help switches will give you some insight into what options the installer provides. Alternatively, you can check the documentation for the software to get the same information. Try to use the /?, /h, or /help flags when running the package to see if they provide any helpful output.
ACL
Access Control List
apt (Linux)
Advanced Package Tool. Linux package manager with package repository
What's the difference between an EXE file and an MSI file? Check all that apply.
An EXE file is an executable that may have an MSI file as one its resources; An executable or EXE file can "wrap" an MSI file, which is used by the Windows Installer to guide the installation process of an application. MSI files are used by the Windows Installer to control how your application is installed.
Which of the following is a characteristic of the FAT32 filesystem? Check all that apply.
It doesn't support files larger than 4GB; The FAT32 filesystem is great for cross-platform compatibility, but has lots of limitations that don't make it useful for large data storage. its read and write compatible with Windows, Mac, and Linux OSes Its filesystem size can't be larger than 32GB
inode
LInux equivalent of MFT record stored in an inode table
"man pages"
Linux - see the manual pages on particular command. i.e. man ls
<
Linux - stdin redirector - instead of getting input from a computer, get it from a file.
df
Linux - tells you how much free space is available on your machine
mkpart
Linux command to partition a disk within interactive parted tool. requires 4 pieces of info - type of partition - file system - start of the disk - end of the disk
less <filepath>
Linux command which is the same as Windows more
softlinks
Linux equivalent of a symlink
Superuser
Linux equivalent to an administrator
mkfs
Linux shell command to format a partition with a file system. i.e. sudo mkfs -t ext4 /dev/sdb1
Linux defragmentation
Linux spreads out files more evenly around the disk and so avoids fragmentation better than Windows. Could happen around 80-90% full at which point you should just get a bigger storage device.
Get-Process
PowerShell command to return a list of running processes. Can use with | format-list *
If you restart a process using the Process Explorer utility, what will the new parent of that process be?
Process Explorer; Since Process Explorer is the process that initiated the restart, it makes sense that the new parent of the process will be Process Explorer.
What are the Linux file permissions?
Read Write Execute rwx
Linux file permission number
Read - 4 Write - 2 Execute - 1
cp -r
Recursively copy directories
Register package source in WIndows
Register-PackageSource -Name <name> -ProviderName <provider name> -Location <URL>
Parent and child
Relationship between directories in a filesystem
RDP
Remote Desktop Protocol - SSH client for Windows
Remove user on Windows
Remove-LocalUser OR net user username /del
For an ssh connection to work, which of the following need to be true? Check all that apply.
SSH is installed on client; To SSH into a remote host, you'll need all of these things setup. The SSH server is running on theist you want to connect to You need to specify a hostname to SSH into
SCP
Secure Copy Protocol (for transferring files over SSH)
Smss.exe
Session mgr subsystem - sets up resources for the OS to work - first non-kernel user mode that starts when computer boots - kicks off logon process and csrss
Most shared libraries in Windows are managed by which of the following?
Side-by-side assemblies, or SxS; The SxS system is used in Windows to manage shared libraries. Most of these shared libraries are stored in the C:\Windows\WinSxS folder.
3 I/O streams
Standard In - stdin Standard Out - stdout Standard Error - stderr
suspend process in Linux
TSTP kill -TSTP pid continue it - kill -CONT pid
disk cloning
Taking a PC and making duplicates of the hard drive, including all data, software, and configuration files and transferring it to another PC. (See image installation.)
a volume
a complete file system, like a file system formatted on a partition
disk partition
a section of a hard disk drive that is treated as a separate storage unit
In Linux, what's the difference between a hardlink and a softlink? Check all that apply.
a softlink points to a filename; Softlinks are used to point to filenames, while hardlinks point to inodes. a hardline points to ani node. you can view the hardline count of a file using ls -l.
driver
a software component that helps the hardware devices interact with the OS on W, the right driver is often found by searching hardware's hardware ID, assigned by its manufacturer found in device manager in Windows
administrator
a user who has complete control over a machine
In Bash, which of the following commands can you use to view the contents of a document.
cat; You can use the cat and less command to view the contents of a file. less
passwd
change password in Linux
cd ~
change to the home directory
Linux device types
character devices (i.e. keyboard or mouse) accept input on character at a time - represented by file type c block devices (i.e. thumb drive or CDROM) transfer a block of data - represented by file type b
fsck
check and repair a Linux filesystem
change group command Linux
chgrp
Although NTFS is largely a self-healing filesystem, which of the following tools can you run to try to locate and repair serious disk corruption of the C: drive?
chkdsk /r c: ; The chkdsk utility, combined with the /r flag, will scan the filesystem on the drive supplied (in this case, C:) and attempt to fix any errors it encounters.
grant all permission to everyone in Linux on a file
chmod 777 filepath
If I wanted to change permissions of a file called honey_bears, what command could I use to grant write access to the owner of the file without changing other permissions? The owner currently only has read access to the file. Check all that apply.
chmod u+w honey_bears; You can use the symbolic or numerical form of chmod to modify permissions, but to use the numerical form you need to know what all of the existing permissions are to avoid unintended changes
change the owner of a file in Linux
chown i.e. sudo chown username filepath
taskkill
cmd.exe command that ends a process taskkill /pid <PID number>
history
command which shows a list of previous commands you've used in the shell
MFT (master file table)
contains information about files when a file is deleted, its entry in the MFT is marked free so it can be reassigned
cp
copy a file
In Linux, what's the difference between the commands df and du? Check all that apply.
df is used to find the amount of free space on an entire machine; The df, or disk free, command is used to find the amount of free space on an entire machine, while the du, or disk usage, command is used to find the disk usage on a specific directory. du is used to find the amount of disk usage on a specific directory;
What's the difference between apt and dpkg? Check all that apply.
dpkg is used as a standalone Debian package command; The dpkg command is used as a standalone package installer, while the apt command is used as a package manager that installs package dependencies. apt installs package dependencies apt is used as a package manager.
dll
dynamic link library - code shared by many different programs most shared dlls are located at C:\Windows\SxS
In a Linux machine, you have a file named "types_of_fish.txt" and you want to append the word "trout" to the file contents. Which of the following commands can you use?
echo trout >> types_of_fish.txt; The >> is used as an append redirector.
You're given the output of an ls -l of a file in Linux. 1 ls -l books_file 2 3 dr-x-wxr-- 1 phelan cool_group 0 Aug 20 11:10 books_file Answer the following question: What permissions does the second trio of bits (-wx) give you? Check all that apply.
execute; w and x are the write and execute permissions. write
True or false: In modern versions of Windows, it's necessary to periodically run a Disk Defragmentation process manually to keep your disk healthy.
false; Nowadays, Windows schedules a task to take care of the defragmentation process in the background automatically for you.
True or false: If you want to save space on a Windows computer, deleting the pagefile.sys file is a good idea.
false; You might free up some space by deleting the pagefile.sys, but this is the location of the swap file in Windows. If you remove it, then your programs will only use RAM memory, which might cause a performance degradation if you run out.
grep
find words or strings of characters inside files Linux
Find-Package
finds software packages that are available in your software package sources
sls or Select-String
finds words or strings of characters in a given document i.e. sis <filepath> Windows
Linux logs
found in /var/log directory /var/log/syslog is the most comprehensive
In a Linux machine, you have the following files: apple.txt banana.jpg chocolate.txt orange.txt What command can you use to search for the word "fruit" in the text files in the above directory? Check all that apply.
grep fruit apple.txt chocholate.txt orange.txt; You can use the grep command to search files for certain words. You can also use the * wildcard command to filter by a specific pattern. grep fruit *.txt
grant permission to a file for everyone on Windows
icacls filepath /grant 'Everyone:(Permission)'
ls -l
in Linux, lists directories in a list-like fashion
ls -a
in Linux, shows all files in a directory, including hidden files
sudo apt install sudo apt remove
install a package on linux remove a package on linux
Journaling File System
is one that keeps track of the information written to the hard drive in a journal. this can also help the system to recover from corruption.
In a Linux machine, what command can you use to absolutely kill a process with a PID of 342?
kill -KILL 342; To kill a process, you'd use the SIGKILL signal.
In a Linux machine, what command can you use to suspend a process with a PID of 342?
kill -TSTP 342; To stop or suspend a running process, you'd send the SIGTSTP signal.
In a Linux machine, what command can you use to safely terminate a process with a PID of 342?
kill 342; To terminate a process safely, send the SIGTERM signal.
kill process tree (Process Explorer)
kills a malfunctioning process and all its child processes
Restart (Process Explorer)
kills a process and restarts it as a child process of Process Explorer
mkdir
make directory
mounting (as in a file system)
makes the file system accessible
closed source package
means you cannot see the source code that created the software. Common in Windows, mainly to protect the intellectual property in proprietary software
create a symbolic link in WIndows
mklink (cmd.exe) or CreateSymbolicLink (PS)
create hardlink in WIndows
mklink /h (cmd.exe) or CreateHardLink (PS)
Which of the following commands in Windows will create a symbolic link called "cauliflower" to a file named "broccoli.txt?"
mklink cauliflower broccoli.txt; The mklink command will, by default, create symbolic links in the form of mklink <link name> <file name>.
mv
move a file or directory
add a user on Windows from the CLI
net user username /add
add a user on Windows from the CLI and make them change their password when they log in
net user username /add /logonpasswordchg:yes
how to make a user change their password on the next login in W
net user username /logonpasswordchg:yes
how to change password in Windows CLI
net user username password add an * after username, gives you privacy to enter password
chocolatey
package manager and repository for Windows
Linux shell command for disk partitioning and formatting
parted supports both MBR and GPT
process for creating swap space in Linux
parted /dev/drivename print for details mkpart primary linux-swap beginning end q sudo mkswap /dev/drivenamepartname sudo swapon /dev/drivenamepartname
change passwd in Linux shell
passwd username enter old pw enter new pw confirm new pw
parent process
processes can only be started by other processes. parent processes initiate other processes, called child processes. once a process starts, it is able to operate independently from the parent i.e. if I used PS to open notepad, PS would be the parent, notepad would be the child
view running processes on Linux
ps -x or ps -ef (shows ALL running processes on the computer)
Which portion of the PuTTY package allows you to perform file transfers using the SCP (Secure Copy) protocol?
pscp.exe; The pscp.exe tool, or PuTTY Secure Copy Client, will let you copy files to and from remote computers using SCP.
>
redirector. Can be used to send results from a command somewhere else. i.e. echo woof > dog.txt takes the text woof and saves it into a document in the current directory called dog.txt
rm
remove a file
rm -r
remove directory
In Bash, which of the following commands can you use to remove a directory named: "Miscellaneous Directory?"
rm -r Miscellaneous\ Directory; To remove a directory you have recursively remove the files with -r. Don't forget that folders with spaces in the name have to be escaped with an \.
If you were investigating login issues on a Windows computer, which portion of the Event Viewer logs would be a good place to start your investigation?
security; The Security log would be a good place to start when troubleshooting login issues.
kill (Linux)
sends the SIGTERM signal to a process if you need to immediately end a process, kill -KILL PID#
Hard link
shortcut that points to the linked file record number instead of the number. This means if you rename the original file, the link still works
-head
show just the first few lines of a file. i.e. cat filename.txt -Head 10 (W)
-tail
show just the last few lines of a file i.e. cat filename.txt -Tail 10 (W)
Get-PackageSource
shows all package sources the computer knows
Get-Alias
shows the equivalent PowerShell command for an alias. i.e. Get-Alias ls shows that ls is an alias for Get-ChildItem
top (Linux)
shows top processes that are using more resources on the machine
You want to format a partition with NTFS, and know that the data you'll be storing will consist mostly of many small files. In order to use as little space as possible, should you choose a larger or smaller Allocation Unit Size during the formatting process?
smaller allocation unit size; With a smaller block size, you'll waste less space if your files are small.
security patch
software that fixes a security hole
/dev/sda or /dev/sdb
storage devices in Linux
how to make someone change their password next time they log in Linux
sudo passwd -e username
add a user on LInux
sudo useradd username
remove a user on Linux
sudo userdel username
parts of a Linux group structure
sudo:x:27:kevin group name password - encrypted group ID members
sudo
superuser do - Linux equivalent of executing a command temporarily as an adminsitrator
What's special about the SxS dll system
supports access to multiple versions of the same shared library automatically
daemon process
system process. Also typically a background process. they manage many things including, scheduling resources, logging, managing networks
defragmentation
takes files stored on a given disk and reorganize them into neighboring directories so they can be more easily access by rotating HDDs SSDs should not be defragmented. They have their own similar function called trim
archive command in Linux
tar
how to get PID in Windows
task mgr, click details on a task OR tasklist or Get-Process in the CLI
partition table
tells the OS how a disk is partitioned
APPX
the format of apps in the Windows store
Init
the kickoff process in Linux
True or false: Windows processes can operate independently of their parents.
true; Unlike in Linux, after a child process is created in Windows and inherits its parent's environment, the parent process can be terminated and the child will continue to run.
/etc/group
where to find group information in Linux
Directory
A folder in a file system.
Which of the following correctly describes a "Security Patch?"
A piece of software that's meant to fix up a security hole. That's the purpose of a security patch!
symbolic link
A pointer to another file on the same or another filesystem; commonly referred to as a shortcut.
FAT32
A version of the FAT file system used by hard drives and some flash drives (thumb drives, etc.), using a 32-bit file allocation table.
.deb
Debian Software Package
DACL
Discretionary Access Control List contains information about who can use a file and what they are allowed to do with it.
how to manage and partition disks in Windows
Disk Management utility this is accessible through the Computer Mgmt utility as well
lsof
Display a list of open files and what processes are using them (Linux)
blkid
Displays or modifies block id attributes of disks
ext4
File System used by Ubuntu, and many common Linux systems. Doesn't usually need defragmentation.
What's the correct commandlet to use in order to find a software package in the available package sources from the PowerShell command line?
Find-Package; The Find-Package commandlet is the way to go if you want to locate a particular package and its dependencies.
Before you can store files on a hard drive, which of the following has to be done? Check all that apply.
Format a filesystem; Before you can start using a hard drive to store files, you'll need to partition the disk, format a filesystem, then mount the filesystem. Partition the disk Mount the filesystem
GPT
GUID Partition Table - new standard unlimited number of partitions, larger volume sizes. GPT is needed for UEFI booting
Which of the following PowerShell commands will tell you which process on your system is using the most CPU resources?
Get-Process | Sort CPU -descending | Select -first 1 -Property ID,ProcessName,CPU; That command will do the trick. It will filter the output of the Get-Process commandlet to determine the top user of the CPU resource, and give its Process ID, name, and the amount of CPU used.
In Linux, in the /dev directory, devices that start with sd can be associated with what type of device? Check all that apply.
Hard drives; The /dev/sd* devices are associated with mass storage devices. USB drives Memory sticks
Which of the following is the piece of information that Windows will use to search for the right driver for a new piece of hardware connected to a Windows computer?
Hardware ID; The Hardware ID will be used by the operating system to search for the appropriate driver for the newly connected hardware device.
If you have a slow computer, what are some possible culprits that could be causing this?
High CPU usage; A slow computer could be a sign of lots of things, but it's always smart to first check the utilization of your resources. Lots of I/O activity High RAM usage Too many processes running
Get-Help
How to get more information on a command's functionality within PowerShell
dpkg
Installs .deb package files on Debian based systems with -i installs with -r removes with -l shows a list of all the .deb packages on the computer * does NOT include dependencies
du -h
Human readable estimate of file space usage
Install-Package
Install a package in WIndows specify name and source
.rpm
Install package in Red Hat Linux
Which of the following PowerShell commands will install the package "awesomesoftware" from the Chocolatey software source?
Install-Package -Name awesome software -Source chocolatey; This command will install a (fictional) package, using chocolatey as the software source.
side-loading
Installing a mobile app by some means other than downloading it from an official app store.
What are the basic linux file permissions? Check all that apply.
The three basic file permissions in Linux are read, write, and execute.
What's the difference between a GPT and MBR partition table? Check all that apply.
MBR only allows you to have volume sizes of 2TBs or less; MBR has a few legacy traits that are being slowly faded out by GPT. GPT doesn't have a limit to the amount of partitions you can make GPT allows you to have volumes sizes of 2TBs or greater
MBR
Master Boot Record - type of partition table old and limited, being phased out. volume sizes of 2TB or less, and a maximum of 4 primary partitions on a disk
uptime
Measures how long the system's been running, how many users logged on, and the load average of the machine
.msi
Microsoft Installer package file
Which of the following tools allows you to create or edit MSI files?
Orca; The Orca tool, that's part of the Windows SDK, will let you work with MSI files.
/etc/shadow
The file that contains the encrypted password as well as password and account expiry parameters for each user account.
In Linux, what could a device named /dev/sdb2 refer to?
The second partition of the second hard drive detected on the system; Device partitions are denoted by numbers after the device drive.
swap space
The space on the disk reserved for the full virtual memory space of a process.
UUID
Universally Unique Identifier (for block devices)
UID (Linux)
User ID
When would you want to use an MSI file to guide the installation of a program, as opposed to an EXE?
When you want the Windows Installer to perform bookkeeping and setup for your application, at the cost of following the rules the Installer requires; Using the Microsoft Installation Package format to guide a program's setup is a good way to get a lot of functionality out of the box. It does mean you'll need to follow the rules and format the Windows Installer requires.
chkdsk
Windows command to check the disk. if you want it to fix the problems it finds, run chkdsk /F
more <filepath>
Windows command to show just one screen full of a document. You can scroll through it.
cleanmgr.exe
Windows disk cleanup utility
dependencies
additional pieces of software that are required to make an application work
>>
adds text to a file without overwriting Is this the actual intended function?
Which of the following tools can help you gather information about the processes running on a Windows operating system?
all of the above; All of these tools can help you gather information about processes running on a Windows OS.
You're given the output of an ls -l of a file in Linux. 1 ls -l books_file 2 3 dr-x-wxr-- 1 phelan cool_group 0 Aug 20 11:10 books_file Answer the following question: Who does the last trio of bits (r--) in the file permission and attributes refer to?
all other users; The last trio of permission bits refers to the permission of all other users on the machine.
| pipe
allows us to use the output of one command as the input for a new one.
apt update apt upgrade
apt update provides you with the most recent apt repository info apt upgrade upgrades the apt repository to the most recent version
Before you install software, which of the following commands should you run to get an updated version of your software?
apt update; Before you install any software, always make sure you're pulling the latest software from your repositories with the apt update command.
Windows 10 updates
are cumulative so you don't need to update through every version to get to the newest one
You're given the output of an ls -l of a file in Linux. 1 ls -l books_file 2 3 dr-x-wxr-- 1 phelan cool_group 0 Aug 20 11:10 books_file
books_file is a directory; The first character in output reflects the type of directory entry; in this case, a directory.
ls
list directory command in Windows and Linux
create hardlink or softlink in Linux
ln -s (softlink) ln (hardlink)
/etc/fstab
location of file systems table in Linux
In Bash, which of the following commands can you use to view the contents of a document. Check all that apply.
ls -la /home; You can use the ls command with the -la flags to show a long list of all files in a directory. ls -l -a/home
In a Linux machine, you want to list through a directory called /home/ben/Documents and search for the word "important" in the filenames in that directory. Which of the following commands can you use?
ls /home/ben/Documents | grep important; You can use the | command to pipe the output of one command into another.