• In fixed length records, if N is the size of each record, then the ith record will be available at the position n*(i-1)

Disk Interface Standards Families

• ATA (AT Attachment) range of standards
• SATA (Serial ATA)
• SCSI (Small Computer System Interconnect) range of standards
• SAS (Serial Attached SCSI)
• Several variants of each standard (different speeds and capabilities)

Disc Controller

• Disc controller accepts high-level command to read or write a sector.
• Disc controller provides interface between the computer system and the disk drive hardware.
• Disc controller initiates action moving the disk arm to the right track.

SSD vs HDD

• SSD is faster
• SSDs do not include moving parts unlike HDD

Flash Storage

• NAND flash is cheaper than NOR flash.

Optical vs Magnetic Disk Storage

Read and write is faster in magnetic disk than optical disk.

Rotational Latency