A+ 1001: Mass Storage Devices Flashcards
Mass Storage Devices
- Optical Media
- Magnetic Media
- Solid State
Minimum Storage unit
- Magnetic media: Sector - 4096 Bytes
- Solid State Media: blocks
- Optical Media: tracks
LBA logical block addressing
Its the device driver for the mass storage device, usually included within the mass storage device
When the operating system wants to save data on the hard drive, it communicates with the LBA unit, which will allocate the required amounts of “blocks” for the data to be saved to.
Capacity
base 10
1000 bytes = Kilo
1000 kilo = mega
1000 mega = giga
1000 giga = terra
1000 tera = peta
1000 peta = exa
base 2 (IEC Values/LBA values)
2^10 = 1024 = Kibi 2^20 = Mebi 2^30 = Gibi 2^40 = Tebi 2^50 = Pebi 2^60 = Exbi
Form factors
5.25 inch: Optical drives mass storage
Form factors
- 25 inch: Optical drives
- 5 inch: SATA Hard Drive
- 5 inch: Laptop hard drives
- 8 inch: SSD
m. 2 SSD (stick)
Magnetic Disk Drives
A motor, Platters and arm inside
The Platter contains Tracks/Cylinder and Sectors
The arm has a read/write head, that reads the 1s and 0s
ATA
Advanced Technology Attachment
The language/protocol used to communicate with LBA driver
eSATA
eSATA connectors on motherboard that are designed to be used externally, with external drives (mostly replaced by usb)
eSata connectors can be installed on motherboard with an expansion card
SATA
SATA: Serial ATA
SATA connectors have L-Keys
Setting up SATA Drive
Connect data and power cables
Boot into BIOS to check if it shows up in system setup
SSD
Solid State Drives
The drive is made up of:
Chips > Pages > Blocks
formats: 2,5 inch, 1.8 inch, m.2
Interfaces: SATA & NVMe
Sata interface runs at 6Gig/Second
NVMe (non-volitale memory express) (m.2 drives are NVMe)
NVMe connectors on the mother board has only one notch.
SCSI
Small computer System Interface
An older Hard Drive that used Parallel ATA
Modern SCSI uses serial SCSI connectors
Two modern standards are: ISCSI and SAS SCSI
ISCSI are SCSI devices connected via ethernet
SAS SCSI are Serial Attached SCSI)
Boot Order
Once POST is complete the system will look for a storage device to boot from
The boot order specifies the order that the system will boot from
Can Set boot order in BIOS / CMOS setup
Mass storage is organized into __________?
Storage is organized into Logical Blocks (LBAs)
Which is a standard command and connection standard for mass storage devices?
ATA
Advanced Technology Attachment (ATA) is a command and connection standard for mass storage devices. Form factors are not command or connection standards. LBA is an organization structure for mass storage devices.
Using SATA, how is data passed between the computer and hard drive?
SATA uses a serial data transfer protocol. Data is transferred one bit at a time from the drive to the computer and one bit at a time from the computer to the drive.
SSDs are organized into logical blocks, but their memory storage cells are called what?
SSD memory cells are called pages. Magnetic drive storage units are called sectors
Which interface is the fastest? SATA, PATA, SCSI, or NVMe?
NVMe
NVMe uses PCIe lanes and is the fastest of these interface choices. PATA is the slowest; SATA and SCSI speeds fall between NVMe and PATA.
Combine SCSI with SATA to get ____________?
Serial Attached SCSI (SAS) uses the SATA connector with the SCSI command language
Running SCSI commands over Ethernet is called __________?
iSCSI uses SCSI commands sent over Ethernet
Which is a likely reason for a computer to fail to boot?
When the boot order has been set to a non-bootable device
A computer cannot boot from a non-bootable device or media. USB drives, optical drives, and SSDs and are all valid boot devices (but will only boot if they contain a working, properly-created bootable drive image).
How to format and partition a brand new hard drive
Windows
boot from window image
select custom install
format and partition
Linux
Boot from linux image
Click on something else option
format and partition
RAID
Redundant Array of Inexpensive Disks (RAID)
Type of drive organization
RAID 0
Striping
Saves the different pieces of a file on different drives
Advantages:
- Speed
Downside:
- no data safety. If anyone of the drives die, then data will be lost
RAID 1
Mirroring
Saves duplicate copies of data on different drives
Advantages
- redundancy (data safety)
Disadvantage
- Slow
RAID 5
Striping with parity
Minimum of three drives
Uses striping, breaking files into pieces and saving different pieces on different drives
But then uses an algorithm to create a parity piece from the pieces saved and saves the parity on the third hardrive
Advantages:
- Fast
- Redundancy (if any one of the hardrives die, then the parity piece can correct or fill in the missing data
Downside
- if you lose more than one drive then data will be lost
RAID 6
Striping with parity
minimum of 4 drives
uses striping to break up file and save different file pieces on different drives,
Then use algorithim to produce two parity pieces based on data saved and then stores the parity pieces on two different drives
Advantages
- Speed
- Redundancy
RAID 10
Striping mirrors
minimum of 4 drives (2 mirrored pairs each running RAID 1)
Uses striping to break up a file and saves different pieces of file on the different mirrored pairs
Advantage
- if you lose on drive in a mirrored pair, you have redundancy
Downside
- if you lose a mirrored pair, then you lose the data
RAID 0 + 1
Opposite of RAID 10
minimum of 4 drives (2 striped sets)
Data is striped onto first pair, then mirror by the second pair
Advantage
- can lose a complete pair and data will be OK
Disadvantage
- if you lose a drive in each pair then data will be lost
How to setup raid
- Hardware + BIOS
2. Through OS
Hardware RAID setup
Either install RAID controller or use RAID controller on mother board
Boot int BIOS, and change from AHCI to RAID mode
Reboot
Should see the RAID code flash on screen with buttons to press CTRL + R to enter in RAID Array configuration screen
initialize disks
Creat an Array
Choose RAID type
continue boot
RAID hot spare /swappable drive
Spare drive used to replace a dead drive when it dies
Troubleshooting mass storage: Before doing anything
- BACK IT UP
2 Mental Reinstall (retrace installation steps)
3 Tripple check
Troubleshooting: Raid not found/working
things to consider:
- Is the RAID controller properly connected
- Is the RAID controller active
- Are the right drivers installed
Trouble Shooting: Read/Write Failure
Likely Causes
- End of life
Diagnostic tool:
- SMART scan
Actions:
- Replace the drive
Troubleshooting: Slow performance
Likely Cause:
- not enough ram
Diagnostic
- the read/write led on drive is off the charts
Actions
- get more ram
Trouble Shooting: loud clicking noise
The great click of death
The hard drive is physically breaking
Replace the hard drive
Troubleshooting: Failure boot
likely cause:
- messed up the boot order
Actions
- Setup boot order in BIOS
Troubleshooting: Drive not recognized
Likely Cause:
- the drive has a formating problem
- Disk not initialized
Actions
- format and partition drive
- initialize disk
trouble shooting OS not found
Likely causes
- messed up boot process (a thumb drive in the usb)
-
Trouble shooting: attempts to boot incorrect device
Like cause
- messed up boot order
Troubleshooting: continuous reboots
Likely causes:
- corrupted OS, can’t boot properly
What is the minimum number of drives to perform RAID 5?
3
What is the maximum number of drive failures under RAID 6 at which the array will still function?
A RAID 6 array will function with up to two drive failures.
Which is an example of a hardware RAID controller?
A dedicated RAID controller comes in the form of an expansion card
What is the name of microsoft’s software RAID implentation?
Storage Spaces is a Microsoft software RAID implementation
RAID 10 requires how many drives?
Of the choices here, the most likely result of a corrupt operating system is continuous reboots. Boot order is set in the UEFI/BIOS system setup utility. A corrupt OS can cause crashes and reboots, not slow performance. Hard drive clicking comes from a mechanical failure inside the hard drive.
