Editing USB mass storage device class (section)

== Design ==
Some advanced [[hard disk drive]] commands, such as [[Tagged Command Queuing]] and [[Native Command Queuing]] (which may increase performance), [[ATA Secure Erase]] (which allows all data on the drive to be securely erased) and S.M.A.R.T. (accessing indicators of drive reliability) exist as extensions to low-level drive command sets such as [[SCSI]], [[ATA command set|ATA]] and [[ATAPI]]. These features may not work when the drives are placed in a [[disk enclosure]] that supports a USB mass-storage interface. Some USB mass-storage interfaces are generic, providing basic read-write commands; although that works well for basic data transfers with devices containing hard drives, there is no simple way to send advanced, device-specific commands to such USB mass-storage devices (though, devices may create their own communication protocols over a standard USB control interface). The [[USB Attached SCSI]] (UAS) protocol, introduced in USB&nbsp;3.0, fixes several of these issues, including command queuing, command pipes for hardware requiring them, and power management.

Specific USB&nbsp;2.0 chipsets had proprietary methods of achieving SCSI pass-through, which could be used to read S.M.A.R.T. data from drives using tools such as [[smartctl]] (using the {{mono|-d}} option followed by "chipset").<ref>{{cite web|url=http://sourceforge.net/apps/trac/smartmontools/ticket/25#comment:17 |title=#25 (SCSI pass through for SMART via USB on MacOSX smartmontools? 3rd party code available!) – smartmontools |website=Sourceforge.net |access-date=2014-01-21}}</ref> More recent USB storage chipsets support the [[SCSI / ATA Translation]] (SAT) as a generic protocol for interacting with ATA (and SATA) devices.<ref>{{cite web |url=http://sourceforge.net/apps/trac/smartmontools/wiki/USB |title=USB smartmontools |website=Sourceforge.net |access-date=2014-01-21 |url-status=dead |archive-url=https://web.archive.org/web/20120207000458/http://sourceforge.net/apps/trac/smartmontools/wiki/USB |archive-date=2012-02-07 }}</ref> Using esoteric ATA or SCSI pass-through commands (such as secure-erase or password protection) when a drive is connected via a USB bridge may cause drive failure, especially with the [[hdparm]] utility.<ref>{{cite web|url=https://ata.wiki.kernel.org/index.php/ATA_Secure_Erase |title=ATA Secure Erase - ata Wiki |website=Ata.wiki.kernel.org |date=2013-07-22 |access-date=2014-01-21}}</ref>