Hard Drives & RAID PM Video 10:28 1.5 Install and configure storage devices and use appropriate media PM Video 10:28

Selecting a Hard Drive Some considerations when selecting a hard drive: Drive capacity Today’s hard drives range from 60 GB – 10 TB Spindle speed (measured in RPM) Common spindle speeds are: 3600, 5400, 7200, 10,000, and 15,000 RPM The higher the RPMs, the faster the drive Interface standard Make sure to use standards the motherboard supports Cache or buffer size Ranges from 2 MB to 64 MB

Before Installing a SATA Hard Drive Be aware that some SATA drives have 2 power connectors Choose only 1 to use Never install 2 power cords at the same time because you risk damaging the drive If you have a SATA drive but have a PATA connector (or vice versa) Purchase an adapter to make the drive fit the motherboard connection Can also purchase a SATA and/or PATA controller card

Steps to Install a SATA Drive Turn off the computer Decide which bay will hold the drive Slide the drive into the bay and secure it Use correct motherboard SATA connector Connect a 15-pin SATA OR 5-pin Molex power connector to the drive Verify drive recognized correctly via BIOS setup Check all connections and power up the system

Before Installing a PATA Drive Open the case and decide how to configure drive(s) Set the jumpers on the drive(s) To determine correct master/slave configuration look at the front of the drive If you only have 1 hard drive, set the drive’s jumpers to master Most drives have a diagram on the sealed housing that explains how to set the jumpers properly If you have 2 drives, set 1 to master and 1 to slave

A PATA drive most likely will have diagrams of jumper settings for master and slave options printed on the drive housing

Use Cable Select to Install a PATA Drive Some PATA hard drives use a setting called cable select to be used instead of master and slave jumpers The position on the cable determines which drive will be master or slave For example, master is on the end of the cable and slave is connected in the middle To use cable select you must set both drives as cable select and use a special “cable-select” cable A cable with one pinhole through the wire is a “cable-select” cable

A special “cable-select” cable can be used instead of master and slave configurations on a PATA hard drive

Steps to Install a PATA Drive Decide whether to connect the data cable before or after inserting the hard drive inside the computer case Connect the data cable to IDE connector on motherboard Install a molex power connection to each drive Before replacing computer case cover, verify installation

S.M.A.R.T. – Self-Monitoring Analysis and Reporting Technology S.M.A.R.T. YT Video 7:21 S.M.A.R.T. is a function of the BIOS and is used to predict when a hard drive is likely to fail S.M.A.R.T. – Self-Monitoring Analysis and Reporting Technology For HDDs S.M.A.R.T. monitors mechanical activities of the drive and for SSDs it monitors wear leveling

To do a quick S.M.A.R.T. check without installing any third-party software, you can use a few commands included with Windows Open a command prompt window and type: “wmic” (press enter) then type “diskdrive get model, name, size, status” If everything is working properly, you should see the status OK displayed Other statuses can indicate problems or errors retrieving S.M.A.R.T. information

What is the Most Valuable Part of a PC?

Protecting Data Option 2: Use 2 or more drives to store your data in what is known as a RAID array Option 1: You can do backups and when a hard drive dies, reinstall the OS and restore data from a backup You need to have a method to prevent data loss Losing data can put a company out of business One of the most expensive parts of a PC is data

Protecting Data with RAID YT Video 3:11 PM Video 5:54 RAID (Redundant Array of Inexpensive Disks) Also: Redundant Array of Independent Disks A technology that configures 2 or more hard drives to work together as an array of drives All of the drives in an array connect to a controller Why use RAID? To improve fault tolerance by writing 2 copies of data, each to a different hard drive To improve performance by writing data to 2 or more hard drives so that 1 drive is not excessively used

RAID controller provides 4 SATA internal connectors

Types of RAID 1 5 There are many types of RAID, but the A+ exam focuses on RAID: 1 + 0 NOT RAID: Spanning – sometimes called JBOD (just a bunch of disks) Uses 2 hard drives to behave like 1 drive When 1 drive is full, data simply overflows into the next

RAID 0 – Disk Striping RAID 0 – uses 2 or more physical disks I remember this as 0 level of redundancy Writes to physical disks evenly so that no 1 disk receives all activity Windows calls RAID 0 a striped volume It does not provide data redundancy; if any 1 drive fails, all data is lost

RAID 0 (STRIPING)

RAID 1 – Mirroring (or Duplexing) RAID 1: Mirroring or Duplexing – uses 2 or more physical disks with 1 or 2 controllers Duplicates data on 1 drive to another drive and is used for fault tolerance (mirroring) RAID 1 – Mirroring (or Duplexing) Storage space is lost because data is duplicated Example: You need 2, 100 GB drives to store 100 GB of data RAID 1 can be set up to use an additional raid controller (duplexing) With 2 drives on separate controllers, the system will continue to operate even if 1 of the controllers stops working

RAID 1 - Mirroring Drives RAID 1 - Duplexing Drives

Sound confusing? 4 + X = 9 (1 DISK FAILURE) Y + X = 9 (2 DISKS FAIL) RAID 5 – Parity Checking Sound confusing? 4 + X = 9 (1 DISK FAILURE) RAID 5: uses 3 or more physical disks Parity data is stored on a different disk for each write operation Data is striped across drives and uses parity checking Data is not duplicated but when 1 drive fails, the array can calculate the missing data on the fly Y + X = 9 (2 DISKS FAIL)

RAID 1+0 Combination: RAID 1 (mirroring) RAID 0 (striping) RAID 10: RAID 1+0 (pronounced RAID one zero) Combination: RAID 1 (mirroring) RAID 0 (striping) Takes at least 4 disks and is the most expensive RAID to implement A RAID 10 will always have an even number of disks

Hardware RAID vs Software RAID RAID can be implemented through hardware or software but hardware outperforms software A RAID hardware implementation involves: A Hardware RAID controller or RAID controller card Motherboard does the work and Windows is unaware of the hardware RAID implementation Software implementation uses the operating system For the best RAID performance all hard drives in an array should be identical in brand, size, speed, and other features

Troubleshooting Hard Drives PM Video 7:25