What is the difference between logical block and physical block?

The logical block size is the size of the blocks that the UNIX kernel uses to read or write files. The logical block size is usually different from the physical block size (usually 512 bytes), which is the size of the smallest block that the disk controller can read or write.

What is a block in a hard disk?

On hard drives and floppies, each sector can hold 512 bytes of data. A block, on the other hand, is a group of sectors that the operating system can address (point to). A block might be one sector, or it might be several sectors (2,4,8, or even 16). The bigger the drive, the more sectors that a block will hold.

What is the difference between page and block?

A block is the smallest unit of data that an operating system can either write to a file or read from a file. What exactly is a page? Pages are used by some operating systems instead of blocks. A page is basically a virtual block.

What is the purpose of logical block addressing?

Logical block addressing (LBA) is a common scheme used for specifying the location of blocks of data stored on computer storage devices, generally secondary storage systems such as hard disk drives.

What is the major difference between logical and physical view of a system?

The basic difference between Logical and physical address is that Logical address is generated by CPU in perspective of a program whereas the physical address is a location that exists in the memory unit.

What is the difference between physical and logical design?

The main difference between logical database design and physical database design is that logical database design helps to define the data elements and their relationships, but physical database design helps to design the actual database based on the requirements gathered during the logical data design.

What is logical sector size?

The physical sector size is what the hard drive actually reads and writes in; the logical sector size is what you can ask it to read or write (and I believe what logical block addresses are in). The physical block size is always equal to or larger than the logical one.

How many blocks are in a hard drive?

Each sector stores a fixed amount of user-accessible data, traditionally 512 bytes for hard disk drives (HDDs) and 2048 bytes for CD-ROMs and DVD-ROMs. Newer HDDs use 4096-byte (4 KiB) sectors, which are known as the Advanced Format (AF). The sector is the minimum storage unit of a hard drive.

What is the difference between block and Cluster?

The block size is the physical size of a block, mostly 512 bytes. There is no way to change this. The cluster size is the minimal size of a block that is read and writable by the OS.

What is the difference between word address and block?

Instead, MAR bit 0 is wired to address bus line 2 , MAR bit 1 is wired to address bus line 3 and so on. The upper 2 bits of MAR are discarded since they are only needed for word addresses above 2^32 none of which are legal for our 32 bit machine.

What is CHS in hard disk?

Cylinder-head-sector (CHS) is an early method for giving addresses to each physical block of data on a hard disk drive. It is a 3D-coordinate system made out of a vertical coordinate head, a horizontal (or radial) coordinate cylinder, and an angular coordinate sector.

What is LBA SSD?

HOST accesses SSD through LBA (Logical Block Address). Each LBA represents a Sector (generally 512B in size) and the operating system generally accesses SSD in 4K. With this mapping, the next time HOST needs to read a HOST Page, the SSD knows where to read the data from FLASH.

What is a block in a drive?

A block, on the other hand, is a group of sectors that the operating system can address (point to). A block might be one sector, or it might be several sectors (2,4,8, or even 16). The bigger the drive, the more sectors that a block will hold. So why are there blocks.

What is the difference between logical and physical address space?

The set of all logical addresses generated by CPU for a program is called Logical Address Space. However, the set of all physical address mapped to corresponding logical addresses is referred as Physical Address Space. The logical address is also called virtual address as the logical address does not exist physically in the memo…

What is the difference between a block address and Sector ID?

usually each block address corresponds to exactly one sector id, but sometimes a block address corresponds to multiple sectors ids. I/O layer of the OS translates disk addresses, expressed as a combination of a drive #, a cyclinder #, a track #, and a sector #, into sector ids (and if necessary block numbers).

What is the maximum size of a block in a disk?

By defining a block as several sectors, an OS can work with bigger hard drives without increasing the number of block addresses. For example, PC DOS (earlier versions at least) could only address 65,536 blocks (64K), and each block could could only be a single sector. Thus, the largest size a disk volume could be was 32mb (64K * 512K).