Week 4 - Filesystem Types - OS Power User

In the context of MFT, what are attributes?

- File Name - Timestamp - Permissions - Compression - Location - etc.

partition table

.tells the OS how the disk is partitioned; . tells you which partitions you can boot from, how much space is allocated to partition, etc

What are ways to check disk capacity usage?

1) Disk Management under Windows GUI 2) DU - disk utility tool in command line

What are the two main partition table schemes that are used?

1) MBR or Master Boot Record 2) GPT or GUID Partition Table

What is one way to launch Disk Management Utility?

1) Right click on "This PC" 2) Select the "Manage" option 3) Click the "Disk Management" console underneath the storage grouping

What are examples of compatability interactions between Windows and Linux systems?

1) an NTSF USB drive can be read and written to by both Windows and Linux's Ubuntu. 2) an ext4 USB drive will only work on Ubuntu and not on Windows, at least without the help of third-party tools.

How does virtual memory make life easier for the OS?

1) doesn't have to worry about what portions of memory other programs might be using 2) doesn't have to keep track of where the data it's using is located in RAM 3) allows the computer to use more memory than is physically installed

How can you partition a disk (USB drive) and format a file system in Windows using command line?

1) insert thumb drive 2) enter "Diskpart" in command line 3) when Diskpart> appears, type "list disk" 4) select the disk (smaller file size suggests the USB drive) by typing "select disk 1" 5) wipe the disk by typing "clean" command 6) type "create partition primary" 7) type "select partition one" 8) type "active" 9) type "format FS=NTFS label = my_thumb-drive quick

How can you partition a disk (USB drive) and format a file system in Windows using GUI?

1) launch Disk Management Utility 2) Insert a USB drive and wait for Disk Management Utility to recognize it 3) Our USB drive is currently FAT32 4) Right click on the partition and choose Format 5) Click yes on the popup menu 6) Change file system to NTSF 7) Decide if you want a quick format or to compress the files 8) Click okay 9) Click Yes in popup screen 10) After processing the label on the drive should read "healthy"

How can you access the system properties applet in Windows?

1) open up Control Panel 2) Go to System and Security setting 3) Click on System 4) Click on "Advanced system settings" on the left-hand menu 5) Select the "Advanced" tab 6) Select "Settings" in the Performance Section 7) Click on "Advanced" tab to reveal a "Virtual Memory" section which displays the paging file size 8) Click on "Change" to modify Windows defaults for paging sizes or add paging files to other drives on the computer

shortcut

A Microsoft Windows feature that directs the operating system to a particular location.

primary partition

A reserved part of a Windows disk, which is identified by a drive letter. The entire C: drive is often one primary partition; however, multiple partitions are created for a user's own organizational purposes or for booting into different operating systems; maximum of four primary partitions

What precaution should you take before physically disconnecting a drive?

Always be sure to unmount a file system of a drive before physically disconnecting the drive. In the case of a USB drive, you can get file system errors if you don't do this.

assign

Assigns a drive letter or mount point to the volume with focus. If no drive letter or mount point is specified, then the next available drive letter is assigned. If the assigned drive letter or mount point is already in use, an error is generated.

create partition primary

Creates a primary partition on the current basic disk

Diskpart

Diskpart is a terminal-based tool built for managing disks right from the command line

inode

In Linux, an ____ stores everything about a file, except for the filename and the file data.

Why doesn't Linux need defragmentation?

Instead of placing multiple files near each other on the hard disk (like Windows), Linux scatters files all over the disk, leaving free space between. When a file is edited, there's usually plenty of free space for the file to grow into. If fragmentation does occur, the file system attempts to move the files around to reduce fragmentation in normal use.

MBR

Master Boot Record; an old standard being phased out a traditional partition table mostly used in the Windows OS; . only allows volume sizes of 2 terabytes or less; uses primary partitions (max of 4)

MFT

Master File Table - administratively documents all files/folders on NTFS volume; Every file on a volume has at least one entry in the MFT, including the MFT itself. Usually, there's a one-to-one correspondence between files and MFT records.

clean

Removes any and all partition or volume formatting from the disk

What happens when you try to open a shortcut file in the command line?

The shortcut file will not work properly using the command line. Example: Create shortcut file: file_1_shortcut C:\Users\cindy\Desktop> cd Links C:\Users\cindy\Desktop\Links> notepad.exe file_1_shortcut.lnk Notepad opens up unreadable text

What are differences between soft or symbolic links (symlinks) and hard links in Linux?

Unlike a hard link, a symbolic link does not contain the data in the target file. It simply points to another entry somewhere in the file system. This difference gives symbolic links certain qualities that hard links do not have, such as the ability to link to directories, or to files on remote computers networked through NFS. When you delete a target file, symbolic links to that file become unusable, whereas hard links preserve the contents of the file.

journaling file system in Windows

a fault-resilient file system in which data integrity is ensured because updates to directories and bitmaps are constantly written to a serial log on disk before the original disk log is updated. In the event of a system failure, a full journaling filesystem ensures that the data on the disk has been restored to its pre-crash configuration. It also recovers unsaved data and stores it in the location where it would have gone if the computer had not crashed, making it an important feature for mission-critical applications.

self-healing in Windows

a mechanism that makes changes to minor problems and corruptions on the disk automatically in the background. use fsutil to check the status of the self-healing process: Example: fsutil repair query C:\

volume

a partition that has been formatted into a filesystem

partition

a piece of the disk that you can manage; when you create multiple partitions, it gives the illusion that you're physically dividing a disk into separate disks

extended partition

a primary partition that has been divided up into logical partitions as a means of creating more partitions than the four that would otherwise be possible; can hold a logical partition

How does virtual memory work on Windows?

a program called The Memory Manager takes care of the mapping of virtual to physical memory for our programs and managing paging.

pagefile.sys

a special hidden file on the root partition of a volume in Windows where pages are saved to disk

What does it mean if you try to cd into a directory (of a filesystem on a USB drive you just partitioned and formatted) and you get a message saying that the file is not a directory?

after you partition and format a file system, the file needs to be mounted to a directory on your computer

How do we use the interactive mode of parted to partition a disk and format a file system on a USB drive?

by running sudo parted "file" to get to the parted tool Example: sudo parted /dev/sdb print {this shows us details of the file} mklabel gpt {to label the disk and use gpt partition table} print {to show it got labeled correctly} mkpart primary ext4 1Mib 5Gib print {to check results} quit {to leave the part tool and make further changes using command line} sudo mkfs -t ext4 /dev/sdb {to format the partition with the file system} sudo parted -l {to check results}

How does virtual memory give a computer the ability to use more memory than is physically installed?

dedicates an area of the hard drive to use as a storage base for blocks of data called pages; When a particular page of data isn't being used by an application, it gets evicted - copied out of memory - onto the hard drive. OS keeps the most commonly accessed data pages in RAM which is easier/faster to access.

What happens to manually mounted disks when you shut down your computer?

disks are automatically unmounted

hard links in Linux

don't point to a file; they link to an inode which is stored in an inode table on the file system. hard links point to a physical location on disk or more specifically on the file system. If you deleted a file of a hard link, all other hard links would still work.

one kilobyte

equal to 1,000 bytes

one kibibyte

equal to 1,024 bytes

What is the recommended filesystem for Linux (ubuntu)?

ext4

symbolic links

file substitutes that operate like the originals on a file system level; different than a shortcut in that it operates independently whereas with a shortcut you could not, for example, use the cd command.

FAT32

filesystem that supports reading and writing data to all three major operating systems (Linux, Windows, MAC); doesn't support files larger than 4 gigabytes; the size of the filesystem can't be larger than 32 gigabytes

fstab

filesystems table; typically lists all available disk partitions and other types of file systems and data sources that are not necessarily disk-based, and indicates how they are to be initialized or otherwise integrated into the larger file system structure. read by the mount command, which happens automatically at boot time to determine the overall file system structure, and thereafter when a user executes the mount command to modify that structure

How would you partition a drive in Linux?

go into parted tool and select /dev/sdb sudo parted /dev/sdb print mkpart primary linux-swap 5GiB 100% *Note - 100% means use remainder of drive print quit {to get out of parted tool} sudo mkswap /dev/sdb2 sudo swapon /dev/sdb2

virtual memory

how our OS provides the physical memory available in our computer (like RAM) to the applications that run on the computer; creates a mapping, of virtual to physical addresses.

swap space

in Linux, the dedicated area of the hard drive used for virtual memory

file metadata

includes the owner of the file, permissions, size of the file, it's location on the hard drive, etc.

How do we create a soft link in Linux?

ln -s filename filename_softlink Example ln -s important_file important_file_softlink

How do we create a hard link in Linux?

ln filename filename_hardlink ln important_file important_file_hardlink

mkpart command

make a partition; needs the following three pieces of information: 1) what type of partition you want to make 2) what file system you want to format 3) start and end of the disk

mounting

making something accessible to the computer, like a file system or a hard disk; Windows does this automatically

active

marks the partition as active

How can you permanently mount a disk you need to automatically load up when the computer boots?

modify a file called /etc/fstab and blkid Example: cat /etc/fstab sudo blkid

GPT (GUID Partition Table)

partition table scheme that is becoming the new standard for disks; . - 2T or greater volume size - one type of partition - unlimited partitions Note: To use UEFI booting, your disk has to use the GUID Partition Table

parted tool

partitioning command line tool that supports both MBR and GPT partitioning; can be used in two modes: 1) interactive which launches us into a separate program and 2) command line - running commands while still in the shell

system properties applet

provides a way to modify the size, number and location of paging files in Windows

What would you do if you had important files on an ext4 USB drive that you want to copy over to your Windows, Linux, and Mac OSes?

reformat or wipe the USB drive and add a filesystem that's compatible with all three operating systems

data buffer

region of RAM that's used to temporarily store data while it's being moved around

cluster size (allocation unit size)

represents the smallest amount of disk space that can be used to hold a file. When file sizes do not come out to an even multiple of the cluster size, additional space must be used to hold the file (up to the next multiple of the cluster size). On the typical hard disk partition, the average amount of space that is lost in this manner can be calculated by using the equation (cluster size)/2 * (number of files).

How do you get the UUID of our devices?

sudo blkid

How do you mount a filesystem in Linux?

sudo mount "file you want to mount" "directory you created on computer" Example: sudo mount /dev/sdb1 /my_usb/ cd /my_usb/ {to start reading and writing to the file system} *Note: often the mounting is done for you when you plug in USB drive

How do we show what disks are connected to the computer using the command line mode?

sudo parted -l

How do you unmount a filesystem in Linux?

sudo umount "filename" Example: sudo umount /my_usb OR: sudo umount /dev/sdb1

What is the recommended filesystem for Windows?

the NTFS filesystem

file record number

the index of the files entry in the MFT

NTFS

the native file system format of windows

How do you run check disc manually in an emergency?

use chkdsk; if you use /F repairs will be made and you can also specify the drive Example: chkdsk /F D:

How do you view the free space available on your entire machine?

use the df -h command (disk free)

How do you view the disk utilization on your computer in Linux?

use the du -h command; if you don't specify the drive it defaults to the current one; The -h flag gives you the data measurements in human readable form.

How can you try to repair a file system manually in Linux?

use the fsck or file system check command; Example: sudo fsck /dev/sda Note: If you run fsck on a mounted partition, there's a high chance that it'll damage the file system. Some Linux versions run fsck when you boot and attempt to auto-repair issues in the file system.

mklink

use to create a symbolic file in Windows Example: C:\Users\cindy\Desktop\Links>mklink file_1_symlink file_1.txt Open result in notepad: C:\Users\cindy\Desktop\Links> notepad.exe file_1_symlink Notepad opens up correct readable text

filesystem

used to keep track of files and file storage on a disk

defragmentation

utility that rearranges files to be stored in contiguous clusters; can manual do by typing in disk defragmenter Note: solid state drives use Trim

Why do you have to unmount or safely eject a flash drive?

when you copy something from your OS to your USB drive, it first gets copied to a data buffer because RAM operates faster than hard drives. you run the risk of data corruption if the buffer doesn't have enough time to finish moving data

hard link

with this link, an entry is added to the MFT that points to the linked file record number, not the name of the file. If the file name of the target changes, the link still points to it. create using mklink with the /H option Example: C:\Users\cindy\Desktop\Links>mklink /H file_1_hardlink file_1.txt

soft links or symlinks in Linux

work like shortcuts in Windows;