HDD disappears in Windows 8

you can use the automount command in disk part - so it mounts them automatic
run disk part -select disk

automount enable

Hi nobus,

it happened again last night and nothing logged in eventvwr... i have enabled it just now, lets see what's gonna happen.

What brand drive?

Run a harddrive diagnostic on it. I use GsmartControl for general-purpose SMART Check and self tests:
http://gsmartcontrol.sourceforge.net/home/index.php/Downloads

I'll also run the manufaturer-specific tool like SeaTools for Seagate Drives or Data Lifeguard for WD drives:
https://www.lifewire.com/barts-stuff-test-review-2624555

It does sound like your HDD may be failing. Somewhat ironically, HDDs are mostly likely to fail early in their lifespan or later in their lifespan, with them less likely to fail during the middle of their lifespan. It's not uncommon for defects to show up after just a little while. The good news is that it's still under warranty and you can get it replaced, and once you get a drive that works early on, it'll likely last you years.

Also, unless you really need 8TB in a single drive, you may want to go with lower capacity ones. 8TB drives are a fairly new capacity, and when HDDs push capacity like that, it takes a while for them to work out the kinks on reliability. 4TB drives are probably currently more reliable, in terms of having less failures.

i use the ubcd for this  - it contains all diags i need
Hardware diagnostic CD    UBCD
---------------------------------------------------
go to the download page, scroll down to the mirror section, and  click on a mirror to start the download
Download the UBCD and make the cd   <<==on a WORKING PC, and boot the problem PC from it
Here 2 links, one to the general site, and a direct link to the download

since the downloaded file is an ISO file, eg ubcd527.iso - so you need to use an ISO burning tool
if you don't have that software, install cdburnerXP : http://cdburnerxp.se/

If you want also the Ram tested - run memtest86+ at least 1 full pass,  - you should have NO errors!
 
For disk Diagnostics run the disk diag for your disk brand (eg seagate diag for seagate drive)  from the HDD section -  long or advanced diag !  (runs at least for30 minutes)

http://www.ultimatebootcd.com/      

**  you can make a bootable cd - or bootable usb stick
*** note *** for SSD drives  use the tool from the manufacturer, like intel 's toolbox :
https://downloadcenter.intel.com/download/18455/Intel-Solid-State-Drive-Toolbox

for completeness -here's how i handle disk problems : https://www.experts-exchange.com/Storage/Hard_Drives/A_3000-The-bad-hard-disk-problem.html

==>>****in order to be able to  boot from CD or usb - you may have to disable secure boot in the bios

UBCD is really good if you need to check the system drive, especially if its having problems booting. However, since it's a secondary drive, running the utilities from Windows instead of booting from UBCD seems easier.

i use it for all - i don't trust the windows versions as much as  the Dos one

Hi Guys,

It's a WDC WD80PUZX 8TB drive.
As this PC is a remote one so it's hard for me to do tests from BIOS, however the test from WD Data Lifeguard Diag and GsmartControl were all showing me PASS (Quick test tho), do i have to run extended test at this stage?
QuickTest.png

the Q test tests the basic operations of the drive : seek, read, write, speedon a limited number of tracks

if the problem is related to sectors in the rest of the disk - you have to run the Long test, in this case i suppose it's gonna be looooonnngg

do bad sectors cause this kind of problems? is it possible that it's a Windows system issue?
i will run extended test today and post result when it's done.

This morning, i got an onsite guy changed sata cable as well as sata port, resat the sata power cable, then rebooted the PC, then it disappeared after 2 hours.

>>  do bad sectors cause this kind of problems? is it possible that it's a Windows system issue?  <<  YES  Windows are hundredsof thousands of files written on the disk - so if some sectors go bad - no telling whta the result can be

Try turning off any powersave or sleep options and see if the drive stays visible.  I suspect something more like this and that Windows doesn't know the drive is gone to sleep or such.

tx for backing me - dbrunton !

the PC was set up as a NAS and is never going to sleep, double checked power settings,
the extended test finished and no bad sector found, all passed...
someone suggested me to reformat it with 64k block size, already done so, will post back results.

so i have formatted the drive and problem still exists, any idea or suggestions please?

@nobus
it backed up to C drive (2TB) before,  i use this backup software (Shadow Protect) in a few other companies as well, never seen this before. but it is the first time i ever use 8TB drive.

@dbrunton
it feels like it's more of a windows problem, i will put this drive on another machine and see if it drops.

the second idea sounds good too, i will give it a try as well.

is it possible to test the drive + software on another PC?
that would show if the problem lies with pc or not

so, i got this drive acctached to another Windows 8 machine as a test yesterday, so far it has been working fine.

it looks like it's the windows problem, but i have ran following cmd on the PC in problem
Dism /Online /Cleanup-Image /RestoreHealth
and
SFC /scannow
corrupted files have been restored but still, it didnt help.

At this point, a complete OS re-install on the PC may be needed.

You said this PC was going to be used as a NAS. Have you thought about installing FreeNAS on it instead of Windows? It could reduce overhead and improve performance. Here's a basic guide:
http://www.tecmint.com/installation-of-freenas/

what pc model was the first?  and the second?  
both Bios - or UEFI ?

tx for feedback!

tried this out and it worked for this problem