Hi,

 

One of my 2TB disks is dying, so I'm going to replace it this week with a 4TB disk.

I would like to preclear the new 4TB using an USB adapter.

 

I've already done this, the preclear went through without any problem, but after installing the hard drive on a SATA port and powering the machine on, it's like unRAID had "forgotten" about this disk. I had to clear it again (plugged to a SATA port) before adding it to the array.

 

Is preclearing using an USB to SATA adapter possible? My problem is that I don't have any free SATA port, so I'd like to leave the array running while preclearing new disks since it takes days to clear a 4TB HDD. I'm asking this before trying mostly because of the very long time it would take to "check" if it works.

 

Thank you!

I've done this without any issues.

 

Note that if you are using unRAID v6 it is important that you use the latest version of the pre-clear script.  Earlier versions did something wrong (I think with writing the unRAID pre-clear signature) that could result in the symptoms you mention.  However that fault occurred on both SATA and USB connections so maybe your problem was something else.  It may also be important that the USB adaptor can handle drives of the size you mention.

From what I remember, and I could be wrong, you don't get the full smart information from USB.

That could have changed, but that's what I remember. Plus you are limited to around 30MB/s (unless usb 3.0 is working now).

 

 

So while you can do the pre-clear. I think you need to redo the preclear signature after it is installed in the sata port.

Then check all the smart information manually. Look for the amount of reallocated sectors and/or any pending sectors.

Pending sectors = bad, do not use for unRAID.

 

 

FWIW, I have a dell laptop with esata port and a external trayless SATA housing specifically for these cases.

Boot with a flash in basic mode and preclear on the extra machine. Used dell 4200,4300,6400,6410 are pretty cheap these days.

Granted not everyone has the budget for this sort of thing, just throwing it out there.

Hi and thank you both for your replies.

 

I'm taking note that I need the new preclear script for unRAID 6. I wouldn't have thought of that.

 

Using a spare laptop is a great idea. I happen to have a few unused laptops with eSATA ports, I'll be giving it a try !

Thank you !

You are correct about the lack of SMART information.   

 

When I tried it on a new 6TB drive and an USB dock the pre-clear signature appeared to be OK.  Also I was using USB 3.0 on unRAID v6 which was similar in speed to a direct SATA connection.

These are the units I use.

 

StarTech SAT3510BU2E Aluminum 3.5" Black eSATA USB Trayless SATA External Hard Drive Enclosure

(The fan doesn't last long on these. )

http://www.newegg.com/Product/Product.aspx?Item=N82E16817707169&cm_re=trayless_sata-_-17-707-169-_-Product

 

 

USB 2.0/eSATA Dual Hard Drive/HDD Desktop Docking Station with Card Reader, SIM Port, & Dual USB Ports

(Although mine was branded d2 communicator and I think I purchased it from monoprice).

http://www.newegg.com/Product/Product.aspx?Item=9SIA1SK1883785&cm_re=dual_esata_dock_card_reader-_-0N6-00T7-000N0-_-Product

 

 

SANS DIGITAL TR4UTBPN 4Bay USB 3.0 / eSATA Hardware RAID 5 Tower RAID Enclosure (no eSATA card bundled)

http://www.newegg.com/Product/Product.aspx?Item=N82E16816111149

 

 

I'm planning to go with one of these,

Orico 6518US3-BK USB 3.0 2.5 " & 3.5 " SATA Hard Drive Dock Station, ( I would probably use a usb fan with this)

http://www.newegg.com/Product/Product.aspx?Item=9SIA1DS0FR8421&cm_re=orico_sata-_-9SIA1DS0FR8421-_-Product

 

and a pair of these for the future.

Oyen Digital Mobius 5-Bay FireWire 800/eSATA/USB 3.0 RAID Enclosure

http://www.bhphotovideo.com/c/product/1062451-REG/oyen_digital_3r5_eb3_m_mobius_5_bay_raid_enclosure.html

 

 

 

Point is, I usually purchase units with usb and esata interface so I can move them around between machines and get the biggest bang for the buck. I'll usually do something by purchasing a combo controller that has eSATA ports and/or run one from in the machine to a PCI bracket with SATA also.

You are correct about the lack of SMART information.   

 

When I tried it on a new 6TB drive and an USB dock the pre-clear signature appeared to be OK.  Also I was using USB 3.0 on unRAID v6 which was similar in speed to a direct SATA connection.

 

 

Good to know about the USB 3.0 thing! Thanks for the update, I'll have to try it out somehow. None of my junktops or external units have USB 3.0 at the moment.

If USB 3.0 drives are running at full speed, it might be useful to allow them to be added to an array!

 

Note that I WAS able to get smart reports when preclearing a USB disk in an enclosure. I had to play around with some smartctl parameters to find a combination that worked. ("-A -d sat" worked for my Seagate USB3 external drive.)

 

See HERE.

If USB 3.0 drives are running at full speed, it might be useful to allow them to be added to an array!

 

Note that I WAS able to get smart reports when preclearing a USB disk in an enclosure. I had to play around with some smartctl parameters to find a combination that worked. ("-A -d sat" worked for my Seagate USB3 external drive.)

 

See HERE.

 

I made a feature request here. Chime in if you are interested.

 

Add support for USB array devices. w Experimental support as unRAID array drives

http://lime-technology.com/forum/index.php?topic=35976.0

Well, that'd be nice !