Hot-swap SATA and atacontrol

Justin Finkelstein justin at
Tue Aug 2 09:23:23 GMT 2005

OK, so how can I be sure that the controller DOES support hotswap SATA?
I've tested pulling and replacing the drive several times while the system's
on, umounting and remounting it to no ill affect.

atacontrol's capability list below shows me lots of info, but I don't know
how that relates to hotswap.
one point is that the case comes with a hotswap backplane and I presume that
the Supermicro board that's running the SATA should support hot-swap - it's
running an Intel 6300ESB controller, and afaik that supports hot-swap.

ATA channel 1, Master, device ad2:

Protocol              Serial ATA v1.0
device model          ST3160827AS
serial number         4MT0J7AA
firmware revision     3.42
cylinders             16383
heads                 16
sectors/track         63
lba supported         268435455 sectors
lba48 supported       312581808 sectors
dma supported
overlap not supported

Feature                      Support  Enable    Value   Vendor
write cache                    yes      yes
read ahead                     yes      yes
SATA NCQ                       yes       -      31/0x1F
SMART                          yes      yes
microcode download             yes      yes
security                       yes      no
power management               yes      yes
advanced power management      no       no      65278/0xFEFE
automatic acoustic management  no       no      0/0x00  254/0xFE

-----Original Message-----
From: Søren Schmidt [mailto:sos at] 
Sent: 02 August 2005 10:11
To: Justin Finkelstein
Cc: 'Colin King'; freebsd-current at
Subject: Re: Hot-swap SATA and atacontrol

On 02/08/2005, at 9:42, Justin Finkelstein wrote:

> OK; so, what you're saying is that it'll be ok to pull the drive if
> I've
> unmounted it?
> In that case, is the atacontrol step unneccesary? My thinking is  
> that it
> might be, but it's just another step to ensure nothing goes wrong.


If the SATA controller supports hotswap ATA will notice when you yank  
the drive and detach it properly from the system (ATA wise, if  
mounted you get into trouble). Also it will autodiscover any SATA  
driver added, again only on supporting chipsets (and those I know how  
to handle).

- Søren

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