Quantum ATL PowerStor L200 Series, Руководство пользователя

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Chapter 4 SCSI Interface
General SCSI Bus Operation
ATL PowerStor L200 Series Library User’s Guide 55
Bus Parity Errors
4
Bus parity errors (i.e. single bit errors) are very serious because they
imply the possibility of undetected double-bit errors on the bus, which
most likely would result in undetected data corruption. On properly
configured SCSI buses, parity errors are extremely rare. If any are
detected, they should be addressed quickly by improving the
configuration of the SCSI bus. A well configured SCSI system in a
normal environment is virtually free of bus parity errors.
Bus parity errors cause the library to retry the operation, go to Status
phase, or go to bus free and prepare sense data. Retrying parity errors
during Data Out Phase is normally not done, however, by changing
the EnaParErrRetry parameter in the Vendor Unique (VU) EEROM
Mode Page, retrying parity errors can be enabled. This feature is not
enabled by default because of negative impacts on device
performance.