ITEC1420_Chapter 5-1.pptx

What is Storage? Storage is considered any medium data can be written to and retrieved from Long-term storage includes: – USB memory sticks (flash drives) – Secure Digital (SD) cards and Compact Flash (CF) – CDs and DVDs – Magnetic tape – Solid state drives – Hard disk...

What is Storage? Storage is considered any medium data can be written to and retrieved from Long-term storage includes: – USB memory sticks (flash drives) – Secure Digital (SD) cards and Compact Flash (CF) – CDs and DVDs – Magnetic tape – Solid state drives – Hard disk drives Public 1 © Cengage Learning 2015  What is Storage? Server storage is based on hard disk drives (HDDs) – Although solid state drives are gaining popularity. Solid state drive (SSD) - uses flash memory and the same type of high-speed interfaces as traditional hard disks – Usually uses SATA or SATA Express interfaces – Has no moving parts, requires less power, and is faster and more resistant to shock than HDD. – Do not have the capacity of HDDs Public 2 © Cengage Learning 2015  Reasons for Storage We need storage for: Operating system files Log files Virtual machines Database storage User documents Etc… Public 3 © Cengage Learning 2015  Storage Access Methods Four broad categories of storage access methods: – Local storage – Direct-attached storage (DAS) – Network-attached storage (NAS) – Storage area network (SAN) Public 4 © Cengage Learning 2015  Local Storage Local storage - storage media with a direct, exclusive connection to the computer’s system board through a disk controller. – Almost always inside the computer’s case – Usually refers to HDDs or SDDs instead of CD/DVDs – Provides rapid and exclusive access Disadvantage: only the system where it’s installed has direct access to the storage medium. Public 5 © Cengage Learning 2015  Direct-Attached Storage Direct-attached storage (DAS) - similar to local storage but can also refer to one or more HDDs in an enclosure with its own power supply. Public 6 © Cengage Learning 2015 Network-Attached Storage Public 7 © Cengage Learning 2015  Network-Attached Storage Network-attached storage (NAS) - has an enclosure, power supply, slots for multiple HDDs, a network interface, and a built-in OS tailored for managing shared storage. NAS is typically dedicated to file sharing NAS shares files through standard network protocols such as: – Server Message Block(SMB), Network File System (NFS), and File Transfer Protocol (FTP) Public 8 © Cengage Learning 2015  Storage Area Network Storage area network (SAN) - uses high-speed networking technologies to give servers fast access to large amounts of shared disk storage. Most common network technologies used in SANs are Fibre Channel and iSCSI. Public 9 © Cengage Learning 2015 Figure 4-1 A storage area network Public 10 © Cengage Learning 2015  Configuring Local Disks Configuration of local disks can be divided into two categories: – Physical disk properties - involve disk capacity, physical speed, and the interface for attaching a disk to the system. – Logical disk properties - include its format and the partitions or volumes created on it. Public 11 © Cengage Learning 2015  Configuring Local Disks Disk-storage terminology: – Disk drive - a physical component with a disk interface connector and a power connector. – Volume - a logical unit of storage that can be formatted with a file system. A disk drive can contain one or more volumes – Partition - an older term that means the same thing as a “volume” but is used with basic disk. – Formatting - prepares a disk with a file system used to organize and store files. Public 12 © Cengage Learning 2015  Disk Capacity and Speed HDD capacities are now measured in hundreds of gigabytes – One and two terabyte (TB, 1000 gigabytes) disks are common Factors that affect the speed of HDDs: – Disk interface technology – Rotation speed - servers should have an HDD with a minimum speed of 7200 rpm (10,000-15,000 preferred) Public 13 © Cengage Learning 2015  Disk Capacity and Speed Disk capacity considerations: – Windows installation should be on a separate disk form data. An SSD is a good choice for Windows installation Public 14 © Cengage Learning 2015  Disk Interface Technologies Disk interface - connects a disk to a computer system. – Usually with some type of cable The faster the bus, the faster the system can read from and write to the disk Most common types of disk interfaces: – SATA – SAS – SCSI Public 15 © Cengage Learning 2015  Disk Interface Technologies Serial Advanced Technology Attachment (SATA) - Drives have mostly replaced parallel ATA (PATA) drives. – Advantages: faster transfer times and small cable size. SATA drives are inexpensive, fast, and reliable. Current standard supports speeds up to 16 Gb/s Public 16 © Cengage Learning 2015  Disk Interface Technologies Small computer system interface (SCSI) drives - a parallel bus technology still used on some servers but has reached its performance limits. – Latest variation is Ultra-640 which supports up to 640 MB/s transfer rates. Serial attached SCSI (SAS) - a newer, serial form of SCSI with transfer rates up to 6 Gb/s and higher. – SATA drives can be connected to SAS backplanes – Backplane - a connection system that uses a printed circuit board instead of traditional cables to carry signals Public 17 © Cengage Learning 2015