Legacy HDS Forums

SATA arrays without "Read-after-write Data Protection Mechanism"

Discussion created by Legacy HDS Forums on Mar 14, 2007
Latest reply on Mar 26, 2007 by Legacy HDS Forums

Originally posted by: przemolb



Hello,

according to the following document [url="http://www.hds.com/pdf/wp_157_sata.pdf"]http://www.hds.com/pdf/wp_157_sata.pdf[/url] there is "Read-after-write Data Protection Mechanism" used in HDS arrays with SATA disks. It means that "controller keeps a copy of the original data in cache memory as it writes that data onto the disk. The controller then physically rereads that data into cache memory and uses ?Verify? byte check logic borrowed from the SCSI command set to make sure the correct data has been recorded."
Someone mentioned on this forum that there is a plan to release a new firmware which will let us turn the feature off (so server receives approval from storage when write request comes to cache). Is that true ? If so does anybody know release date of the firmware ?

Regards
przemol

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