- Introduction to Mass Storage
- There are many types of mass storage used today, including hard drives, solid state drives (SSD) and optical media.
- Regardless of the media, your operating system sees mass storage as a string of logical block addresses.
- There is a difference between decimal value and IEC values.
- LBA—Logical Block Address
- Decimal Counting— 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0
- Kilo 1,000
- Mega 1,000,000
- Giga 1,000,000,000
- Terra 1,000,000,000,000
- Peta 1,000,000,000,000,000
- Exa 1,000,000,000,000,000,000
- Binary—more concerned with how many possible patterns
- IEC Values: There can be
- (IEC counting) 00000000 28 = 256 different patterns
- (LBA values)
- 210 = 1024 different patterns
- Kibi = 210 (Not “kilo” because its 1,024 not 1,000 exactly.)
- Mebi = 220 (Mebi = 1,004,576 similar to Mega)
- Gibi = 230
- Tebi = 240
- Pebi = 250
- Exbi = 260
- IEC Values
- Magnetic Disk Drives (HDD)
- Magnetic disk drives use spinning platters to store data via magnetism and read by read/write heads.
- Hard disk drives come in 3.5”, 2.5”, and 1.8” physical sizes.
- We use the AT attachment protocol to communicate with hard disk drives.
- ATA—Advanced Technology Attachment
- PATA—Parallel ATA (outdated)
- SATA—Serial ATA (still used)
- ESATA
- Solid State Drives (SSD) (most popular today)
- SSDs store data using chips; there are no moving parts.
- Data is stored in blocks & pages.
- SSDs come in traditional 3.5” & 2.5” sizes, but also come in M.2 format.
- Some SSD’s use the very fast NVMe (non-volatile memory express) protocol instead of ATA for increased performance.
- Small Computer System Interface (SCSI) (“scuzzy”)
- SAS (Serial attached SCSI)
- The SCSI is an ancient standard that still has great support
- The old parallel SCSI is standard, but the SCSI language lives on in serial SCSI versions.
- Two modern SCSI standards are: SAS (Serial Attached SCSI), iSCSI
- Boot Order
- When a system boots, it looks for a bootable device.
- It’s important to make sure the system looks for the correct boot devices.
- The boot order is defined in the system setup.
- Implementing Mass Storage
- RAID (Redundant Array of Independent Disks)
- A RAID array helps protect our data!
- RAID provides speed and/or redundancy.
- RAID 0 (striping) provides spped
- RAID 1 (mirroring) provides speed
- RAID 5 and 6 (striping with parity) provides speed and redundancy.
- RAID 5 can only lose one drive in the array; RAID 6 can lose two.
- Hardware RAID
- Hardware RAID requires a controller to configure the RAID arrays.
- Hardware RAID has its own BIOS that comes with a special system setup to configure the RAID array.
- The completed array looks like a single drive to the operating system.
- Mass Storage Troubleshooting
- Always back up important data before troubleshooting mass storage
- Use a mental process of installation to make sure all the installation steps have taken place.
- Review the many symptoms & reasons why.
- Optical Media
- Compact Discs (CDs) store 650-700 MB of data
- Digital Video Discs (DVD) store from 4.37 GB to 15.9 GB
- Blu-rays store from 15.6 GB to 50 GB capacity
- All optical media comes in read only (ROM), write once (R), and re-writable (RW) versions.
