Can you safely remove a HDD from a SATA3 rack while power is on ?

[Castor Nageur]

Hi all,

I am actually building my new home computer which will exclusively use
SATA3 hard disks.
For the convenience, I want to have all my hard disks racked.

I read the reviews on NewEgg and most of the recent racks (mostly Icy
Box & Icy Dock) do not have a power off switch.
I know the SATA3 connector is designed to be plug & play but I think
it would be much better is the power could be off while removing the
disk.

In my old computer, I use some Icy Box IB-138SK-B-II SATA2 racks wich
have a mixed lock/power off key but I did not find the equivalent on
new SATA 3 HDD.
These racks work very well and I never met any issues with them (but
they are SATA2 :-().

Here are my questions:

* I found much trayless racks than in the past so what do you think of
them ? Are they as reliable as tray racks (personally, I don't think
so) ?
* Do you thing a hard disk can really be safely removed from the rack
while the power is on ?
* Do you know a robust SATA3 rack model which has a front power off
switch (as far as I am concerned, I did not find one) ?

 

[Castor Nageur]

I have an external disk "cabinet" (it is open, and has only space for
one disk) connected by a cable directly to the motherboard's SATA
interface.  I regularly hot-plug and hot-unplugg devices on it.  I can't
say for sure if it is the power or the sata cable that disconnects first
from the disk.

Yes, as far as I am concerned, I have exactly the same system (a power
& e-SATA cords outside of the case) but I only plug a disk I do not
care of.

 

[Castor Nageur]

One thing to make sure of is that you are not using the disk when you
remove it (umount the filesystem(s) for Linux, or use "safe remove" for
windows).

I am using Windows 7 so that's not a problem because W7 handles hot
swap quite well : the SATA devices are listed with the USB devices and
can be ejected the same way before physical remove.

My main concern is about what happens when the rack and the HDD
connector meet together while the power is on.
I know that electronic components like capacitors does not like it. Of
course, it can work 99% of the times but the remaining 1% will destroy
your drive.

 

[Rod Speed]

Castor Nageur wrote

My main concern is about what happens when the rack and
the HDD connector meet together while the power is on.

The SATA standard has been designed to handle that.

I know that electronic components like capacitors does not like it.

Thats just plain wrong. The problem is quite a different
one, connecting the supply rails before the ground line.

The SATA connectors are designed so that does not happen.

Of course, it can work 99% of the times but the remaining 1% will destroy your drive.

Not with SATA drives that have the connector designed to allow a hot swap.

Thats why you cant fine racks that have a power switch, they dont need one.

 

[Rod Speed]

David Brown wrote

Castor Nageur wrote

Again, you have to make sure it is safe to remove the drive

Nope, it handles hot swap fine.

 

[Arno]

Hi all,

I am actually building my new home computer which will exclusively use
SATA3 hard disks.
For the convenience, I want to have all my hard disks racked.

I read the reviews on NewEgg and most of the recent racks (mostly Icy
Box & Icy Dock) do not have a power off switch.
I know the SATA3 connector is designed to be plug & play but I think
it would be much better is the power could be off while removing the
disk.

In my old computer, I use some Icy Box IB-138SK-B-II SATA2 racks wich
have a mixed lock/power off key but I did not find the equivalent on
new SATA 3 HDD.
These racks work very well and I never met any issues with them (but
they are SATA2 :-().

Here are my questions:

* I found much trayless racks than in the past so what do you think of
them ? Are they as reliable as tray racks (personally, I don't think
so) ?
* Do you thing a hard disk can really be safely removed from the rack
while the power is on ?

Electrically, absolutely. SATA drives are designed for that.
The way this is done is by longer ground traces. There are
also longer power-traces, but they must be unused or protected
by hotplug-curcuitry. The data-lines are actually insulated with
capacitors and only transfer data-pulses.

Mechanically, you can still damage a disk on hot unplug, especially
if you bump it while it is spinning down. This is where the
power-switch makes things safer. That said, disks have gotten
more robust while spinning and if you are reasonable careful,
you sould not damage them by a hot unplug.

Arno

 

[Arno]

I have an external disk "cabinet" (it is open, and has only space for
one disk) connected by a cable directly to the motherboard's SATA
interface. I regularly hot-plug and hot-unplugg devices on it. I can't
say for sure if it is the power or the sata cable that disconnects first
from the disk.

It does not matter, the connectors and electrical connector
attackments are designed for this. The only risk I see is
mechanical damage if you unplug a still spinning disk. This
risks should be low if youa re reasonably careful.

Of course, if you inplug a disk while writing to it,
your data will be damaged.

Arno

 

[Arno]

On 12 sep, 21:06, David Brown <[email protected]>
wrote:

I am using Windows 7 so that's not a problem because W7 handles hot
swap quite well : the SATA devices are listed with the USB devices and
can be ejected the same way before physical remove.

My main concern is about what happens when the rack and the HDD
connector meet together while the power is on.
I know that electronic components like capacitors does not like it. Of
course, it can work 99% of the times but the remaining 1% will destroy
your drive.

Dont't worry, SATA devices are designed for this.

Arno

 

[Castor Nageur]

Electrically, absolutely. SATA drives are designed for that.
The way this is done is by longer ground traces. There are
also longer power-traces, but they must be unused or protected
by hotplug-curcuitry. The data-lines are actually insulated with
capacitors and only transfer data-pulses.

Thanks Arno, that's good to know that.

Mechanically, you can still damage a disk on hot unplug, especially
if you bump it while it is spinning down. This is where the
power-switch makes things safer. That said, disks have gotten
more robust while spinning and if you are reasonable careful,
you sould not damage them by a hot unplug.

It seemed to me that the disk stopped spinning once ejected from
Windows (I could hear the disk slowing down). I noticed this under
Windows XP but I did not test under Windows 7 so I am going to do it.
If true, it means I just have to wait a few seconds before taking the
disk out.
But I suppose it also depends on the disk brand you are using.
(I have WD Caviar Green EADS disks).

 

[Rod Speed]

Castor Nageur wrote

Thanks Arno, that's good to know that.

It seemed to me that the disk stopped spinning once ejected from
Windows (I could hear the disk slowing down). I noticed this under
Windows XP but I did not test under Windows 7 so I am going to do it.
If true, it means I just have to wait a few seconds before taking the disk out.

But I suppose it also depends on the disk brand you are using.

Nope, on the OS and controller.

 

[Mike Tomlinson]

En el artículo <[email protected]

I know the SATA3 connector is designed to be plug & play but I think
it would be much better is the power could be off while removing the
disk.

The connector on the back of SATA drives is designed to be hot
plug/remove. You're worrying too much.

In my old computer, I use some Icy Box IB-138SK-B-II SATA2 racks wich
have a mixed lock/power off key but I did not find the equivalent on
new SATA 3 HDD.

You don't need SATA3 ones. Your existing SATA2 ones will work fine.

These racks work very well and I never met any issues with them (but
they are SATA2 :-().

They're SATA, full stop.

* I found much trayless racks than in the past so what do you think of
them ?

I like them a lot. I use this one: http://tinyurl.com/6j6paav

Are they as reliable as tray racks

Yes, if not more so (fewer connections)

(personally, I don't think
so) ?

How do you know if you haven't used them?

* Do you thing a hard disk can really be safely removed from the rack
while the power is on ?

Yes, it's designed for it! The SATA connector was explicitly designed
for hot plug/removal in RAID arrays.

* Do you know a robust SATA3 rack model which has a front power off
switch (as far as I am concerned, I did not find one) ?

Because you don't need one.

IDE caddies came with a switch because IDE wasn't designed for hotplug.
SATA is.

 

[Mike Tomlinson]

En el artículo <[email protected]

My main concern is about what happens when the rack and the HDD
connector meet together while the power is on.

Look at the data/power connectors on the back of the drive. You'll see
some of the gold fingers are longer than the others. This is to ensure
that these are the first connections to be made when inserting and the
last when removing.

I know that electronic components like capacitors does not like it. Of
course, it can work 99% of the times but the remaining 1% will destroy
your drive.

Nonsense.

 

[Castor Nageur]

The connector on the back of SATA drives is designed to be hot
plug/remove.  You're worrying too much.

Probably but I had memory & disk issues last year so I prefer being
very careful before buying.

You don't need SATA3 ones.  Your existing SATA2 ones will work fine.
They're SATA, full stop.

Do you mean that my SATA2 racks will work at SATA3 speed (up to 6
GBPS) if I plug them if my new SATA3 disk & mobo computer ?

I am surprised because rack's manufacturers seem to make a difference
between their SATA2 and SATA3 racks' in the specifications.

 

[Castor Nageur]

It seemed to me that the disk stopped spinning once ejected from
Windows (I could hear the disk slowing down). I noticed this under
Windows XP but I did not test under Windows 7 so I am going to do it.

I did a simple test by putting my hand on the disk.
I directly hot-plugged 2 of my HDD (Seagate & WD) on the external
eSATA & power connectors.

When ejecting the Seagate Barracuda 7200.12 500 GB (ST3500413AS) disk
from W7, I could notice it kept on spinning.

When ejecting the WD Caviar Green 1.5TB (WD15EARS) disk, it seemed
that it stopped.
I know that WD Caviar Green rotation speed can vary from 5400 RPM to
7200 RPM so it's possible it runs too slowly so I can feel it
spinning.

 

[Rod Speed]

Castor Nageur wrote
Thats just plain wrong later when you have SATA3 ports
on your motherboard and SATA3 drives which come
close to wringing out the SATA physical connection.

I have this external enclosure at home:

It has an eSATA and an USB port and is said to
work at SATA2 speed (up to 3 Gb/s or 375 MB/s).

I plugged the rack on my computer using an eSATA cord and
HDTach reported a speed of 110 MB/s (~ SATA1 like speed).

I directly plugged the hard disk using the same eSATA cord
then HDTach reported 230 MB/s (~ SATA2 like speed).

I never understood what was going wrong (I checked and
there is no switch, no jumper nowhere) but I do not care
because I only use the USB ports.

To me, eSATA is just the electrical continuity of the internal
SATA cable so I do not know how I can lose half the speed

Presumably its the bridge in the external enclosure thats doing that.

and that's why I am asking plenty of questions here about racks ;-)

He's wrong.

 

[Castor Nageur]

Castor Nageur wrote


Thats just plain wrong later when you have SATA3 ports
on your motherboard and SATA3 drives which come
close to wringing out the SATA physical connection.

No, I do not think he is wrong, I we only talk about the SATA
connectors, he is right.
The SATA 1/2/3 connectors are the same so it should not be a problem.
I found this rack which finally works exactly as I expect:

http://www.lian-li.com/v2/en/product/product06.php?pr_index=285&cl_index=2&sc_index=5&ss_index=71

The rear connectors are directly connected to the SATA motherboards
cables : there is no electronic between the rack and the motherboard
so everything is fine.

Presumably its the bridge in the external enclosure thats doing that.

Absolutely, that's what I presume.
I had a look at my current Icy Box IB-138SK-B-II rack and found some
electronic components inside.
I suppose they handle the HDD power LED and they are required by the
power switch to properly switch the HDD off (perhaps there is also a
fan temp control but I am not sure).
Because SATA3 works at higher speed, I suppose there is less
electronic tolerance and that's why manufacturers specify them as only
SATA2.
I don't see any other reason.

 

[Rod Speed]

Castor Nageur wrote

No, I do not think he is wrong,

Corse he is. If he was right, there wouldnt be any point in introducing SATA3 at all.

I we only talk about the SATA connectors, he is right.

There is no difference what so evere with the SATA connector, there is
no such animal as a SATA3 connector, the same connector is used for
all of the SATA, SATA1, SATA2, SATA3.

The SATA 1/2/3 connectors are the same

Yes, but you werent just talking about SATA connectors,
you were talking about SATA3 BAYs, not connectors.

so it should not be a problem.

You're wrong. There are different SATA3 cables for a reason.

I found this rack which finally works exactly as I expect:

http://www.lian-li.com/v2/en/product/product06.php?pr_index=285&cl_index=2&sc_index=5&ss_index=71

Irrelevant to how well it will work with SATA3 ports on the motherboard
and SATA3 drives that really wring out the physical connection.

The rear connectors are directly connected to the SATA
motherboards cables : there is no electronic between the
rack and the motherboard so everything is fine.

You dont know that they will perform as well with SATA3 ports on the
motherboard and SATA3 drives that really wring out the physical connection.

Absolutely, that's what I presume.

I had a look at my current Icy Box IB-138SK-B-II
rack and found some electronic components inside.

Yes, there has to be to provide the USB connection.

Usually called the bridge.

I suppose they handle the HDD power LED

You dont need any electronics for that, there are LEDs which can be
directly applied to the power supply rails without any extra electronics.

and they are required by the power switch to properly switch the HDD off
Nope.

(perhaps there is also a fan temp control but I am not sure).

Because SATA3 works at higher speed, I suppose there
is less electronic tolerance and that's why manufacturers
specify them as only SATA2. I don't see any other reason.

There clearly are SATA3 cables and the same considerations apply
with whats between the end of the cable and the drive connector too.

 

[Castor Nageur]

Just don't un-plug the system/OS disk!

Windows 7 does not allow you to eject the OS disk and you must not
remove a disk without ejecting it before.
So there is no problem.

 

[Castor Nageur]

Yes, but you werent just talking about SATA connectors,
you were talking about SATA3 BAYs, not connectors.

Yes, I thought that all SATA bays were just forwarding the signal from
the HDD to the mobo but I was wrong.

You're wrong. There are different SATA3 cables for a reason.

There clearly are SATA3 cables and the same considerations apply
with whats between the end of the cable and the drive connector too.

Here is what the SATA organisation official document says:

http://www.serialata.org/documents/SATA-Revision-3.0-FAQ-FINAL.pdf

9: Does SATA 6Gb/s require different connectors and cables to support
the higher
transfer speed?
A9: The same cables and connectors used for current SATA 1.5 and SATA
3.0 Gb/s
implementations can be used to connect SATA 6Gb/s devices, although
SATA-IO recommends
quality components be selected to ensure data integrity and robust
operation at the faster SATA
6Gb/s transfer rate. Keeping the existing SATA connector form factor
enables SATA 6Gb/s to
be designed into the same cost-conscious hardware architectures while
minimizing
infrastructure changes.

Q14: Were there any attenuation or jitter issues that had to be
addressed with the jump to
6Gb/s?
A14: Ensuring signal integrity was the primary challenge in doubling
the SATA transfer speed
for a second time while using the same cables and connectors that were
originally defined for
the first generation 1.5Gb/s version.

So yes and no.
The same cables can be used but you need better quality cables for
SATA3 otherwise the induced noise will decrease the transfer rate.
Consequently, you will not reach the 6 GB/s specification (even if a
few HDD actually reach it).

Yes, there has to be to provide the USB connection.
Usually called the bridge.

The IB-138SK-B-II has no USB port. It only includes SATA connector.

http://www.raidsonic.de/en/products/mobile-racks.php?we_objectID=6275

 

[Mike Tomlinson]

En el artículo <[email protected]

A9: The same cables and connectors used for current SATA 1.5 and SATA
3.0 Gb/s
implementations can be used to connect SATA 6Gb/s devices, although
SATA-IO recommends
quality components be selected to ensure data integrity

Quite so. You're wasting your time with Rod, he's full of shit.