What is write same?
WRITE SAME is basically a SCSI operation that tells the storage to write a certain pattern, in this case zeros. So instead of ESXi issuing possibly terabytes of zeros, ESXi just issues a few hundred or thousand small WRITE SAME I/Os and the array takes care of the zeroing.
What is SCSI write same?
Is SCSI Serial or parallel?
Interfaces. SCSI is available in a variety of interfaces. The first was parallel SCSI (also called SCSI Parallel Interface or SPI), which uses a parallel bus design. Since 2005, SPI was gradually replaced by Serial Attached SCSI (SAS), which uses a serial design but retains other aspects of the technology.
Is SCSI Serial or Parallel?
How does a SCSI device send a response?
Finally, the device sends a response information unit to the computer. SCSI commands are sent in a command descriptor block (CDB), which consists of a one byte operation code (opcode) followed by five or more bytes containing command-specific parameters.
What is the SCSI command architecture?
The SCSI command architecture was originally defined for parallel SCSI buses but has been carried forward with minimal change for use with Fibre Channel, iSCSI, Serial Attached SCSI, and other transport layers. In the SCSI protocol, the initiator sends a SCSI command information unit to the target device.
What is the client-server model in SCSI?
In SCSI computer storage, computers and storage devices use a client-server model of communication. The computer is a client which requests the storage device to perform a service, e.g., to read or write data.
What are the lengths of the SCSI CDB?
The lengths are as follows: When a command is defined in multiple CDB sizes, the length of the CDB is given in parentheses after the command name, e.g., READ (6) and READ (10). “SCSI Commands Reference Manual” (PDF).