Chapter 7 Notes - Zacham17/my-tech-journal GitHub Wiki

Zachary Morris

Chapter 7 Notes

Storage Devices Overview: Cloud storage stores data over the internet

Hard Drive Overview; Hard Drives use USB, IEEE 1394, eSATA, or eSATAp There are different sizes of hard drives. 5.25-inch, 3.5-inch, 2.5-inch(SSDs) Hard drives can be external if put into an enclosure Mechanical hard drives are traditionally Magnetic Platters: hard metal surfaces in a hard drive that hold data Data is written and read by the heads using electromagnetism Revolutions per Minute(RPM): Describes the rate at which a hard drive spins Faster RMP = faster transfer rate Head Crash: When a head touches the platter; this can damage the platters and corrupt data Mean Time Between Failures(MTBF): the average number of hours before a drive is likely to fail There are tracks on a Hard drive platter All the same track on each platter is a cylinder Each track on the HD is separated into Sectors

Solid State Drive(SSD) Overview: SSD: storage devices that use DRAM or nonvolatile flash memory technologies. SSDs can be used with hard drives Write Amplification: the minimum amount of memory storage space affected by a write request. Wear Leveling: a technique used to erase and write data using all of the memory blocks instead of using the same memory blocks repeatedly NAND Flash Memory: retains data even when the device is powered off. Single-level memory cell(SLC): store 1 bit in each memory cell and last longer than MLCs, but are more expensive Multi-cell memory cell(MLC): store more than 1 bit in each memory cell, but are cheaper and have slower transfer speeds Hybrid SSD: provides a combination of mechanical and flash technologies.

Hard Drive Interfaces overview: Interface: A standard that governs communication with the hard drive IDE(Integrated Drive Electronics): also known as AT attachment (ATA) Enhanced IDE(EIDE) Small Computer System Interface(SCSI) Parallel ATA(PATA) only supports two devices NAS Drive: Used with network attached Storage(NAS) devices

M.2 and NVME M.2: a connector that allows modules of varying sizes to be connected. Non-Volatile Memory Express(NVMe): provides faster performance when accessing the NAND flash memory in the SSDs.

PATA, SATA, and SAS, Connectivity: ATAPI(AT Attachment Packet Interface) supported more devices than ATA Parallel ATA(PATA): slower and older than SATA Serial ATA(SATA): Faster than PATA; Each device has dedicated link SCSI Connector: for SAS drives; commonly seen by PC technicians SATA cables can’t be longer than 3.3 feet External SATA(eSATA): Provides external device connectivity; allows for cables up to 6.56 feet; fast connections; doesn’t provide power SCSI Cable(SAS Cable): used to connect the hard drives or tape drives to a SAS controller.

Storage Device Configuration Review Termination: A method used to prevent signals from reflecting back up the cable To install storage, keep the drive protected, make sure computer is off and unplugged, put in hard drive , connect computer power, prepare drive for data if hard drive PATA uses master and slave devices Cable select IDE option automatically selects roles for you eSATA ports are sometimes disabled in the BIOS so double check that when installing an eSATA device Mount: when a drive mounts, a communications channel is opened between the drive and the Operating System

System BIOS/UEFI Configuration: SATA drives can operate in different modes: Legacy: used when the system doesn’t have SATA drivers Advanced Host Controller Interface(AHCI): allows SATA drives to be inserted/removed when the power is on and use commands to allow the host circuits to communicate with attached devices in order to implement advanced SATA features RAID: a method of using drives

Hard Drive Preparation Overview: Before use, a drive must be partitioned and formatted Partitioning: allows a drive letter to be assigned to one or more sections of the hard drive; dividing the hard drive into separate sections so the computer system see the hard drive as more than one drive. High-level formatting: prepares the drive for use for a particular file system, which allows the drive to accept data from the operating system There are multiple advantages to Partitioning File System: Defines how data is stored on a drive; examples are FAT16, FAT32, and exFAT, and NTFS Compact Disk File System: A file system for optical media FAT(FAT16): 2GB partition limitation w/ old OS, 4GB limit w/ new FAT32: Supports up to 2TB, can’t create volumes > 32GB exFAT(FAT64): for removable media; theoretically supports up to 64ZB,but 512 is recommended max NTFS: Supports up to 16EB, Faster file access and efficient space usage. Hierarchical File System(HFS): Used with apple computers; upgraded to HFS+ and then APFS Network File System(NFS): Open source file system used in Linux ext3: journaling file system used in linux ext4: update to ext3; ; larger volumes and file sizes Cluster: the smallest amount of space reserved for one file; made up of a specific number of sectors Partition conversion requires free hard drive space Data is more protected from OS failures when partitioned Primary Partition: a partition on the first detected hard drive; always C: Extended Partitions: in old OS, the other cylinders could be extended partitions. Logical Drive or Volume: assigned a drive letter and can include a logical drive and removable media such as CD, DVD, BD, or flash drives Master Boot Record(MBR):contains a program that reads the partition table, looks for the primary partition marked as active, and goes to that partition to boot the system; can have up to 4 primary partitions System Partition: partition on the hard drive that holds the hardware-specific files needed to load the operating system. Boot Partition: the partition on the hard drive that contains the operating system. Boot and System partition can be on the same partition in windows Host Protected Area(HPA): a hidden area of the hard drive that is used to hold a copy of the operating system Globally Unique Identifier(GUID) GUID Partition Table(GPT): allows up to 128 partitions and volumes up to 9.4 ZB Full Format: scans for and marks bad sectors, quick format doesn’t DOS Boot Record(DBR)(aka Boot Sector): area of the disk that contains information about the system files.

Windows Disk Management: Basic Storage: Known as a partition; default used by all OS Basic Disk: Any drive that has been partitioned and set up for writing files Dynamic Storage: Allows you to create primary partitions, logical drives, and dynamic volumes on storage devices. Allows for simple, spanned, or striped volumes Dynamic Disk: A disk made up of volumes; cannot be on a removable drive Simple volume: Disk space allocated from one hard drive Spanned Volume: Disk space created from multiple hard drives; Known as “just a bunch of disks”(JBOD) Striped Volume: Disk space in which data is written across 2 to 32 hard drives; RAID 0 System Volume: Disk space that holds the files needed to boot the operating system Boot Volume: Disk space that holds the remaining operating system Files RAW volume: A volume that has never had high-level formatting performed and that does not contain a file system Basic disks, simple volumes, and spanned volumes can be resized, shrunk, or expanded

Fault Tolerance: Drive Array: involves using two or more hard drives configured for speed, redundancy, or both Redundant Array of Independent Disks(RAID): allows reading from and writing to multiple hard drives for larger storage areas, better performance, and fault tolerance. Fault Tolerance: the ability to continue functioning after a hardware or software failure You need raid drivers when configuring RAID RAID can be configured in the BIOS or RAID BIOS RAID 0(Disk Striping): data is alternately written on two or more hard drives, which increases system performance. RAID 0 doesn’t protect from hard drive failure. Used for speed RAID 1(Disk Mirroring): protects against hard drive failure. The same data is written onto two drives, so if one failed, the system can continue to function RAID 0+1: A striped and mirrored set combined. At least four hard drive required RAID 5: writes data to three or more hard drives. If a drive fails, the data can be rebuilt based on the information from the other two drives. Speed + fault tolerance Hot Swappable: can be removed or installed while power is applied to the computer. Supported by USB, SATA, SAS AHCI Mode: hot swapping may be supported RAID Mode or Discrete SATA Mode: Allows you to select a particular RAID level and the drives associated with the RAID Detected RAID Volume: Info screen that shows the type of RAID configured eSATA Controller Mode: Allows configuration of RAID through the eSATA port eSATA Port x Hot Plug Capability: Allows hot swapping to be enabled or disabled for eSATA ports

Removable Drive A Storage: Tape Drives: can be attached using SATA or can attach to USB, eSATA, or eSATAp May require two USB ports Tapes can be between 12GB and 10TB Most common removable storage is optical discs, USBs, and Hard Drives

Windows Storage Spaces: Windows Storage Spaces: combines drives into a flexible storage option Storage Pool: two or more physical disks that can be different types, such as a SATA drive and a USB drive Storage Space: A virtual disk created from available space in a storage pool Simple: Data is striped across physical disks Parity: Data is striped across physical disks and parity is included Mirror: Data is striped across multiple disks, and the same data is copied for the highest level of resiliency Storage Spaces ar created in control panel

Disk Caching/Virtual Memory: Disk Cache: involves putting data into RAM, where it can be retrieved much faster than if the data were still on the hard drive The read/writes are enabled to read more than one sector at a time Virtual memory uses Hard drive space as if it were RAM Disk Cache is dynamic The paging file is used when extra memory is needed. The paging file is pagefile.sys

Troubleshooting Storage Devices Overview: 22% of hard drives failed within the first four years of use Stay calm and be nice when dealing with angry customers Most hard drives fail because of moving Parts Maintenance is good Lost Clusters: clusters that have become disassociated from dta files but still occupy disk space. Disk Cleanup can be used to remove temporary files, offline internet files, empty the recycle bin, compress unused files, and remove unused programs. Files become fragmented over time Defragmentation: the process of placing files in contiguous sectors. Command: defrag, could be used

Troubleshooting New Storage Device Installation: When a drive isn’t recognized, try checking the physical configurations and the settings in the BIOS Make sure there is at least one partition on the drive Make sure the mounting screws aren’t too tight

Troubleshooting Previously Installed Storage Devices: Hard drives can make noise since they have moving parts Sometimes it is normal, and sometimes it is not Back up a drive when it starts making clicking or tapping sounds because it is failing Viruses or physical tampering could be reasons for a Hard Drive failure Research any S.M.A.R.T errors appear Press F8 on startup for windows startup issues For Read/write errors, check the hard drive with the tools tab in the properties box

RAID Issues: RAID issue symptoms are similar to Hard Drive issues If you get a “RAID not found” error, then check the hardware and software configuration Power surges can mess up RAID

SSD Issues: Possible fixes coud be to reinstall driver, restart PC, try a different SATA port, Turn off Wake on LAN BIOS option Phone communication skills are important In person skill are important too Good things to do are draw a picture, use gestures, show empathy, be nice, be clear, don’t waste anyone’s time