hot swap vs warm swap

[geeta]

Can anybody explain the difference between hot swap and warm swap? To me, they are the same, but apparently- there is a difference which impacts while swapping drives on some particular systems.

Appreciated :)

[David Claypool]

Here is an explanation from the Tape Array 5300 QuickSpecs:

The Tape Array 5300 supports offline hot-swap (sometimes referred to as "warm-swap") tape drive modules. This means the drives can be removed and replaced with the power on and the SCSI cables attached to the server. Because the array's SCSI buses are not buffered, however, drive replacement should only take place while the SCSI bus is quiescent (no SCSI activity from the tape drive or any other device on the same bus). This is similar to HP hot-plug tape drives, though the hot-plug drives are not affected by other devices on the bus. With both hot-plug and offline hot-swap drives, however, the operating system or application may not recognize that a drive has been replaced until the system is rebooted and/or other configuration steps are taken.

http://h18000.www1.hp.com/products/quickspecs/11878_na/11878_na.HTML

[geeta]

So basically warm swap is when there is no I/O to the devices whereas in hot swap there can be I/O while one of the drives is being swapped??

Did i get tht right?

[Basil Vizgin · Accepted solution]

Almost:)
With warm swap entire bus must be quiescented, with hot-swap--I/O stopped (in most cases automatically) only to affected device.

[geeta]

Got it !!

Thanx man !

[geeta]

well explained thanx Basil !