# How Hot swappable is SATA?



## ex-dohctor (Mar 3, 2009)

As above?

How safe is it to plug in/out PC hard discs while the power is on?

I've been told this is possible by powering down the drive through the "Safely remove hardware" feature in most windows OS's but never tried it myself?

Any information will be appreciated. 

Thanks in advance.


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## Mussels (Mar 3, 2009)

SATA is not hot swappable.

SATA II, on a SATA II board, is.

that means DVD drives etc arent going to like you, but its safe with hard drives. As long as no data is being written at the time, take the data cable out, followed by the power cable a few seconds later. that gives it a few seconds to empty its cache/finish any random operations you may have interrupted, before taking the power out.

If you think its madness or going to damage your drive, its no different to unplugging a USB hard drive, or turning your PC off. data stops going, then it loses power.


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## ex-dohctor (Mar 3, 2009)

Many thanks for the feedback Mussels. 

My H.D.D's are all SATA 2 luckily. 

So do I need to power down the drive through windows or is it cool to just unplug the device as indicated above? 

The reason I am asking is because I am setting up a spare machine that will be used for testing customers H.D.D's and maybe some data recovery if I can get the drives working. 

I just didn't want to power down the machine everytime I want to plug in or remove a drive from the machine. 

I have an external carriage I could use for the IDE and SATA devices which connects via Firewire so that isn't a problem.


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## human_error (Mar 3, 2009)

ex-dohctor said:


> Many thanks for the feedback Mussels.
> So do I need to power down the drive through windows or is it cool to just unplug the device as indicated above?



You can do it as above without safely removing via windows, however safely removing it from windows (telling the OS you intend to unplug it) is probably a better idea if you are doing any file transfer/ file creation. 

Most modern OSs often claim to have moved/written a file and it will look like they have in the file view, but actually what they have done is queued up the write operation, the reason behind this is to prevent file fragmentation on newly created files which grow in size quickly after creation but all you need to know is that if you are doing any file moving/modification/creation then getting windows to allow safe removal of the drive is best as it allows all queued write operations to finish correctly, all this can be done without shutting the pc down, just like with a memory stick. The only danger of not safely removing before hot unplugging teh drive is that a file you moved/created/modified may not have been written back to the drive so either the older version of it or no version at all will be on the disk, but the disk itself will not be damaged.


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## Tau (Mar 3, 2009)

Mussels said:


> SATA is not hot swappable.
> 
> SATA II, on a SATA II board, is.
> 
> ...




Both versions of Sata are hotpluggable.

Though some drives, and motherboards can be picky... and windows XP has issues with it.

i hotplug sata drives all day long on one of my machines at work (laptop hdds mostly, but some desktop) and almost never run into issues.


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## Widjaja (Mar 3, 2009)

What I use at work is either a multi adaptor or SATA docking bay.
This way you don't have to touch the motherboard and bump some thing like  stupidly long cap located next to a port which is use all the time.
The multi adaptor needs external power from a sata connector if using SATA though and only uses USB.
The docking bay has it's own power source and can use 3.5" or 2.5" HDD.
There is a docking bay out there which has SD card ports etc included.
The docking bay has the choice of using eSATA or USB as connection to the motherboard.
I prefer the docking bay because all you have to do is put the drive in and away it goes as its always attached.
The adaptor needs to be plugged into the USB port after the drive has been connected.
I safely remove all drives regardless PATA, SATA I or II.


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## Mussels (Mar 3, 2009)

SATA 1 it was *optional* for hotswap support. thats the key there. I've got sata 1 DVD burners here, and some hotplug, while others freeze the machine, for example.

Its a very good idea to use the safely remove if the drive was in use moments before, i've definately seen the windows file transfer thing dissapear, while a bandwidth meter program i use still shows the file being copied across the network.


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## adrianx (Mar 3, 2009)

the problem is from connector

it's preferable to plug first the power and after that the data cable (sata cable)

and when you want to remove a drive from the sistem, remove the sata first and power after. also it's a good idea not to move the hdd from running position in first 30 second after you disconnect the power from hdd. because the hdd heads must return in the landing zone (aka the parking zone for the head/heads). with the head of the hdd in this zone, the risc of the bad sectors are very low (but still exist).

also you can use same hdd racks with hot swap/plug option.

P.S. don't play with the raid array ... same controllers will try to prepare the hdd for the raid ... with a erase command or a zero fill . read the raid controller manual frist 


best regards


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## Tau (Mar 3, 2009)

Mussels said:


> SATA 1 it was *optional* for hotswap support. thats the key there. I've got sata 1 DVD burners here, and some hotplug, while others freeze the machine, for example.
> 
> Its a very good idea to use the safely remove if the drive was in use moments before, i've definately seen the windows file transfer thing dissapear, while a bandwidth meter program i use still shows the file being copied across the network.



That makes sence,  I try to stay as far away from Sata optical drives as i can, as i despise them.  So i cant really comment on that front, though with regular HDDs it usually works fine.


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## ex-dohctor (Mar 3, 2009)

Thanks for all the info guys. 

Using the hot swappable option should save me some time at work. 

Just wanted to make sure before I went ahead and tried it for myself.


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