Implementing Hard Drives

Question 1

Decimal and binary prefixes

Answer 1

Decimal prefixes:
Kilo (k) = 1000
Mega (m) = 100 K
Giga (G) = 1000 M
Tera (T) = 1000 G
Peta (P) = 1000 T
Exa (E) = 1000 P

Binary values: Use a four bit addressing system.

Binary value combinations = 2 ** the number of digits. So it would be 2 to the power of 16.

IEC binary prefixes: 
Kibi (ki) = 2**10 = 1024
Mebi (mi) = 2**20 = 1024 (ki)
Gigi (gi) = 2**30 = 1024 (mi)
Tebi (ti) = 2**40 = 1024 (gi)
Pebi (pi) = 2**50 = 1024 (ti)
Exbi (ei)  = 2**60 = 1024 (pi)

Decimal prefixes were used until the mid-1990’s.

Binary prefixes are more accurate than decimal prefixes.

You need to be comfortable using both interchangeably.

questions// What are the exact values of each?

Question 2

Implementing RAID

Answer 2

Most typical modern motherboards have Hardware RAID built into it.

Hardware RAID requires a dedicated hardware controller or a motherboard that supports RAID.

The vast majority of all motherboards are either all RAID or JBOD (just a bunch of disks).

When you go from AHCI to RAID, all of the controllers become RAID controllers. This means on an existing windows system, windows would have to be reinstalled.

Dedicated RAID controller: Has four SATA controllers and whatever is plugged into them becomes a RAID array.

Dedicated RAID controllers have their own system setup screen upon initial boot.

Hot-Swappable: Is when you can pull out a hard drive within a RAID array and swap it with another while the system in running.

Hot-Spare: Is when you have a RAID 5 Array and a fourth drive is sitting there in case one of the others fail. It will automatically detect if one drive goes bad and rebuild the drive on the fly.

Always use Hardware RAID in place of Software RAID if given the option.

Software RAID: Always make your disks dynamic. This is done through disk management on Windows. You can add a mirror to an existing drive.

SR: Always needs blank drives to start and puts a lot of work on windows.

Spanned volume: This is when one hard drive is full the data then moves to the next hard drive. This is neither mirroring or striping.