Recognizing SMR HDDs

Peter Jeremy peter at
Thu May 26 08:39:32 UTC 2016

On 2016-May-26 08:42:53 +0200, Gary Jennejohn <gljennjohn at> wrote:
>Now that ken@ has checked in the SMR code I'm wondering how I can see
>whether it's having any effect.

camcontrol(8) has been enhanced with SMR options and there's a new
zonectl(8) command - these should be able to report whether the drive
is recognized as a host-aware or host-managed SMR drive.  I believe
that drive-managed SMR drives don't admit to anything.

>Does the fact that the drive appears as a /dev/daX play any role?

USB drives are handled via the SCSI CAM layer rather than as SATA
drives.  It's possible that either the umass(4) driver or your USB
to SATA adapter are not correctly handling the relevant commands.

Peter Jeremy
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