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I have been following this guide on how to secure erase an SSD (trying to improve the performance of mine, which currently only writes at about 30mb/s seq).

However, I'm using an USB-->Sata docking device to avoid having the harddrive frozen. Apparently using this solution the SATA device is recognized as a SCSI drive, which is giving me trouble.

I use the "hdparm -I /dev/sda" command with those parameters, and I get the error;

HDIO_DRIVE_CMD (identify) failed: Invalid Exchange

After a lot of googling on the issue I can't seem to find anyone who has actually solved this problem. However, I have not tried to just go ahead and use the secure erase. So I'm not sure if this would actually still work.

I would love any and all input I can get on this, especially on whether it will still work to do a secure erase with the drive being recognized as a SCSI drive.

The drive itself is a Samsung 256gb SSD (pm800), I'm sure you can understand my reluctance to go through this procedure without feeling reasonably safe that I won't mess it up beyond repair.

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Please elaborate on "avoid having the harddrive frozen". – RolKau Dec 18 '10 at 18:45
Is your docking device USB 3.0? Does you computer have USB 3.0? – liori Mar 25 '11 at 23:26

Probably the USB->SATA device doesn't support passing all the special commands needed to do a 'secure erase', just the minimum number of commands required to use the drive normally.

Also, in my experience, SATA and USB storage devices will always show up as /dev/sdX, they aren't actually being recognized as SCSI, they just use some of the same infrastructure in the Linux kernel.

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