Physical Storage Flashcards
Information is maintained, regardless of whether or not there is power to the disk drive until it is deleted by a software program or user
non-volatile storage
Two types of disk drives
Magnetic & Solid State
Contain one or more round aluminum or glass platters which are coated with several layers of various materials
Magnetic hard drives
Magnetized indicates the binary number ___, demagnetized indicates the binary number ___
1 & 0
Components that make up a Magnetic Hard Drive
Hard drive platters
Drive spindle
Read/write heads
Actuator
Hard Drive Form Factors
- 5” hard drives are most commonly used in desktop and server systems.
- 5” hard drives are most commonly used in laptop computers.
- 8” hard drives were once popular for small laptops and portable media devices, but cheap flash memory means you’ll only find them in older devices.
Data stored on a series of non-volatile flash memory chips
Solid state drives (SSDs)
Type of memory that is permanently installed on the motherboard; common implementation on small laptops and ultrabooks, and almost all mobile phones and tablets
embedded multi-media card (eMMC)
What kind of hard drive is installed on a PCIe card and plugged into a motherboard expansion slot which is used on some high-end workstations?
Solid state drives (SSDs)
Installed onto a small card and plugged into a specialized slot on the motherboard, such as an M.2 or NVMe slot used for newer laptops and high-end desktop motherboards
Solid state drives (SSDs)
Advantages of Solid state drives (SSDs)
Silent
No mechanical wear
Less susceptible to damage from shock or magnets
Faster boot times & better performance
Disk Frag won’t affect performance
Available in smaller form factors
Disadvantages of Solid state drives (SSDs)
More expensive
Flash memory has limited number before memory cells become locked
Magnetic hard drive with flash memory chips added to it
Hybrid Drive
Found in high end servers, specialized workstations, and older Apple hardware
Small Computer System Interface (SCSI)
Connections are most common on older computers
Integrated Drive Electronics (IDE)
Connections are most common for modern hard drives on newer computers
Serial AT Attachment (SATA)
What external Hard Drive requires it’s own power source?
eSATA
Only allows one drive per cable
SATA cables
SATA connectors are designed to be hot-swappable (True/False)
True
An IDE drive connects to the power supply via a _____ connector, and a SATA drive connects to the power supply via a ______ power connector.
4-pin Molex
15-pin SATA
On SATA hard drives, you don’t need to set jumpers to specify drive detection order. (True/False)
True
Look similar to IDE cables, but have 50 or 68 pin connectors and can support more devices.
internal parallel SCSI cables
A parallel SCSI bus supports up to ___ or ___ devices depending on the standard
7 or 15
The physical end of an internal cable or external chain needs a ________ to prevent interference due to signal reflection
terminator
Use connectors and cables similar to SATA, but support more advanced features suited to high performance enterprise storage solutions
Serial Attached SCSI (SAS) devices
Uses the SCSI command set over a USB connector.
USB Attached SCSI (UAS)
Uses the SCSI command set over network interfaces, such as Ethernet.
iSCSI
These drives need to have a device ID to differentiate them from other devices on the bus.
All SCSI drives
Connects directly to the PCIe bus, through the Advanced Host Controller Interface driver provided by legacy operating systems
PCIe over AHCI drives
Connects directly to the PCIe bus using the NVM Express standard designed to leverage the performance benefits of SSDs. It gives increased performance over SATA, but may not be supported by legacy operating systems.
NVMe M.2 drives
Connects to a SATA drive controller. It doesn’t have any performance benefit over ordinary SATA drives, but is compatible with any system that supports SATA.
SATA M.2 drives
For “operating system not found” errors - What is most likely the problem if you can see your hard drive in the BIOS?
The problem lies with the boot manager or boot sector - Use your operating system’s bootable repair disc or the recovery discs provided by your OEM.
If running Windows, what program can you use to troubleshoot and repair the master boot record, boot sector, or Boot Configuration Data store?
Microsoft’s BOOTREC
If system files reside in a bad sector, it can cause a ___________________ or other operating system crash screen.
Microsoft Blue Screen of Death (BSOD)
What command can you run to scan the hard drive for bad sectors?
CHKDSK
Monitors attributes of your hard drive that indicate mechanical wear and degradation of storage surfaces, and reports when those attributes pass set threshold values
S.M.A.R.T. errors: Self-Monitoring, Analysis and Reporting Technology
Things to try when you experience slow performance.
Run CHKDSK to scan for bad sectors on the hard disk, verify file system integrity, and attempt to fix any logical file system errors.
If available, download and run diagnostic software from your hard drive manufacturer’s Website.
If your hard drive is formatted to FAT or FAT32, upgrade to NTFS using Microsoft’s CONVERT command. The CONVERT command changes your file system while keeping your existing files intact.
If you are running Windows, run the Disk Cleanup utility.
Most modern hard drives do not need to be defragmented, but if you are running Windows, you can try running the Defragmenting utility.
Move the data interface cable to a different port on the motherboard.
What is the first thing you should do if you hear an unusual clicking noise?
Back up data - possible HDD failure
Causes of hard drive clicking noises
software or drivers, or by a hardware problem such as a mechanical fault on the drive
Things to check if you hear a clicking noise
If it is a magnetic hard drive, verify the drive is on a level surface.
Verify there are no loose connections. Make sure the interface cable and the power cable or adapter are both good.
If the hard drive is external and receives its power from only the USB port, verify the port is able to supply the correct amount of power.
Update the hard drive’s firmware.
Defragment the drive.
What are some causes of hard drive clicking that require HDD replacement?
The actuator arm hits the internal head stop. This is called the Click of Death.
There are physical problems with the platters.
The hard drive has a faulty circuit board.
What program is used to attempt to gain access to the data on the failed hard drive
a third party file recovery software
Included in Windows and in the Windows installer which allows you to set up a hard drive
Windows graphical Disk Management utility
Command line tools for setting up a new hard drive
diskpart and format
If you install a hard drive and the system doesn’t recognize it or you receive either a “hard drive not found” error or “no boot device available” error, what can you check?
All connections are properly seated - on the hard drive, motherboard, and PSU.
Autodetect is enabled in the BIOS/UEFI.
Jumpers are set correctly on IDE drives.
A bootable disk is available and placed in the BIOS/UEFI boot order.
Your BIOS/UEFI supports large hard drives.
Allows you to configure multiple hard disks into a logical group to improve performance and add fault tolerance.
Redundant array of independent disks (RAID)
Two or more hard drives are configured in which data is saved across an array
Redundant array of independent disks (RAID)
Determines the number of drives you need, and what effects it will have on overall performance.
RAID Level
Works with two or more disks, and the total space is equal to the sum of all drives in the array, but it does not include any fault tolerance.
RAID 0
Known as Disk Striping
RAID 0
Writes identical data to two or more hard drives, also known as disk mirroring
RAID 1
Uses disk striping across at least three drives and includes parity data
RAID 5
Has the read performance increase you’d see with RAID 0, plus it includes fault tolerance without using as much disk space as RAID 1
RAID 5
At least four drives, and two parity disks with a stronger fault tolerance than RAID5
RAID 6
Combines RAID 1 (mirroring) with RAID 0 (disk striping), making it a stripe of mirrors
RAID 10 (1+0)
Requires four hard drives - two hard drives for the disk mirror and then two more disks to stripe the mirrored disks
RAID 10 (1+0)
Hardware instead of software RAID controller allows better ________
Performance & Flexibility
Which RAID levels allows the array to continue to work after one of the drives fails?
1, 5, 10
Common causes of RAID failures include
Drive Failure Controller Failure Power Issues Software Issues RAID Rebuild Stress
Takes the contents of files and spreads them in roughly even parts across all drives in the RAID Array
RAID 0
Requires 4 hard drives, two hard drives for disk mirror, and then two more disk to stripe the mirrored disk
RAID 10
Writes identical data to two or more hard drives
RAID 1
Uses disk striping across at least three drives and includes parity data
RAID 5
DVD dual-layer, single-sided capacity
8.5GB
Blu-ray (pre-BD-XL)
25GB per layer
Blu-ray BD-XL triple-layer
100GB
DVD dual-layer, double-sided
17GB
Blu-ray BD-XL quadruple-layer
128GB
These storage devices are removable and allow you to easily transfer their contents from one device to another.
USB flash drives and flash memory cards
A solid state memory card standard developed by SanDisk in 1994
Compact Flash
A solid state memory card developed by the SD Card Association in 1999
Secure Digital (SD) Card
standard-capacity (SDSC) SD card
1 MB to 2 GB
high-capacity (SDHC) SD card
2 GB to 32 GB
eXtended-capacity (SDXC) SD card
32 GB to 2 TB
Fits into a SD card slot but doesn’t store data. Instead, it’s an input/output adapter, such as a wireless network card.
Secure Digital Input Output (SDIO)
Solid state memory card enclosed in a case with an integrated USB interface.
USB flash memory
Advantages of tape drives and magnetic tape
Reduced energy cost
Reliability
High Capacity
Low cost per GB
Disadvantage of tape drives
The data is recorded on the tape sequentially
Retrieve data at speeds of approximately 1 TB per hour
Typically used for backup and archival purposes where data integrity is important, but data access speed is not
Tape Drives