• Hello, I'm running 6.2.0-rc3 with (1) 2Tb parity drive and (5) 2Tb data drives.
  I would like to physically remove my parity drive and replace it with a WD Red 8Tb
  I've done a parity check on the system and all is good.
  I did install the Beta Preclear plugin and can see the icon in the "Tools" menu under "Disk Utilities"
  I'm a little rusty on this. I have been searching and reading the forums but would like a little help if someone has time.
  
  • Before I shut down the server and physically take the old parity drive out and plug in the new one, do I need to change any settings or prepare in any way?
    
  • When I power up the server with the new drive, I assume the Parity drive will automatically show "Unassigned" under "Main" menu?
    
  • Should I now run the "Preclear" plugin? Is this self explanatory?
    
  • Will there be an "Assign" to start the rebuild process?

 

I'm sorry if these questions sound simple, if someone can please help I appreciate it! I'm also going to replace one of my data drives with a WD Red 8Tb but will tackle that after I get through the new parity drive install. I'm assuming I wouldn't do this at the same time as the parity drive replacement?

 

Thanks,

Tom

 

 

Ideally you would preclear the new drive before removing the old one, since preclear will take days. It is not required to have the new parity clear since it will be completely overwritten anyway, so if you want to you could use the manufacturer's software to test the drive on another system instead of preclearing it.

 

I think unRAID will say the parity drive is missing rather than unassigned when you replace it. Then you can assign the new one are let it sync.

 

It's probably easier to do than to explain. If you get stuck post a screenshot.

Thanks trulr! for the information! I'm going to order a couple of drives and proceed

The safest approach is as follows:

 

(1)  Turn off auto-start so the array doesn't automatically start on boot.

(2)  Stop the array and unassign your parity drive.

(3)  Start the array -- it will show a missing parity drive.

(4)  Stop the array;  then shut it down and replace the parity drive with your new 8TB unit.

(5)  Boot the array;  assign the new drive as parity; and then Start the array.  It will now do a parity sync with the new drive.

 

Done :-)

... You can now turn auto-start back on.

 

Great! Thanks, and appreciated!

And it sounds like a preclear is not necessary?

A pre-clear is not needed.    But you may want to at least test the disk before installing it ... although I've had NO issues with the 8TB WD Reds => these are SUPERB helium-filled units that work VERY well.

 

You could test them using WD's Data Lifeguard on a PC ... just run both the Quick and Extended test.

 

HOWEVER ... they are so reliable I'd be inclined to simply put it in the system and "test" it by doing the parity sync, followed by a parity check.    This will cause the entire disk to be written (during the parity sync); and then everything will be read back and confirmed (during the parity check).    This is effectively as good a test as Data Lifeguard or a single pass of pre-clear would do anyway ... and you need to do the parity sync and parity checks anyway, so it doesn't add any time waiting for the tests.

 

Sounds like a good plan, that is what I will do. I ordered two of these drives today and will receive them Wednesday.

After I get through the new parity drive install I want to replace one of my 2Tb data drives with the other 8Tb WD. This will need a preclear, right? If so, I have the beta preclear plugin installed so hoping I can use it ok? I'm running 6.2.0-rc3.

One more thing, should I turn off the auto-start when replacing a data drive?

 

Thanks

Depending on who I ordered the drive from I would never trust the shipper even if I do trust WD for a good drive from factory.

Actually a pre-clear doesn't save any time when doing a replacement either.    The only time it saves time is if you're adding a drive => if it's pre-cleared, then it can be added "instantly" (will just require a format, which only takes a couple minutes).

 

Pre-clear is still a useful tool for testing the drive; but as I noted above, you can do this offline with WD's Data Lifeguard; or you an simply let the act of writing the drive and then reading it be your test.

 

I'd be inclined to just do that => but if you do that, you should NOT use the system at all during the replacement.  Reason is simple:  If you do effectively what I outlined earlier (yes, you should disable auto-start); and replace the data drive; then when you Start the array it will do the rebuild of the data from your "missing" 2TB drive onto the 8TB drive and update the rest of the 8TB unit with zeroes.  After that, you should do a "non-correcting" parity check (this is the ONLY time I recommend the non-correcting option).    And if all is well, you're done.    But if for some reason things didn't go well, then you can shut down; put the old 2TB drive back; and do a New Config with the "Parity is already valid" option box checked, and you'll be back to where you started.  This will only be true if you did NOT use the array during the rebuilding process.

 

Note, however, that even if you want to use the array, you can still replace the 8TB drive with the original 2TB drive if anything doesn't check out well => you just can't check the "Parity is already valid" checkbox in that case.

 

Yes, I definitely understand it can get damaged in transit. I ordered them from Amazon LLC, not one of their third party sellers. They will be overnighted. I've had extremely good luck in the past. If it doesn't turn out well they have a 30 day return/money back policy including shipping. No one has these local to me.

Depending on who I ordered the drive from I would never trust the shipper even if I do trust WD for a good drive from factory.

 

Agree some distributors have a poor record of this.  Newegg had a bad spell a few years ago, but has been MUCH better in the last year or two.  And Amazon is excellent as long as you order drives that are noted as  "ships from and sold by" Amazon.

 

In any event, the process I outlined does indeed test the drives rather thoroughly -- it just doesn't do that before you've added them to the array.

 

To date, I've bought 8 of the 8TB Reds for myself and others, and have had ZERO issues ... these are VERY nice units.  [FWIW 5 of them were bought from Amazon; 3 from Newegg]

 

 

Actually a pre-clear doesn't save any time when doing a replacement either.    The only time it saves time is if you're adding a drive => if it's pre-cleared, then it can be added "instantly" (will just require a format, which only takes a couple minutes).

 

Pre-clear is still a useful tool for testing the drive; but as I noted above, you can do this offline with WD's Data Lifeguard; or you an simply let the act of writing the drive and then reading it be your test.

 

I'd be inclined to just do that => but if you do that, you should NOT use the system at all during the replacement.  Reason is simple:  If you do effectively what I outlined earlier (yes, you should disable auto-start); and replace the data drive; then when you Start the array it will do the rebuild of the data from your "missing" 2TB drive onto the 8TB drive and update the rest of the 8TB unit with zeroes.  After that, you should do a "non-correcting" parity check (this is the ONLY time I recommend the non-correcting option).    And if all is well, you're done.    But if for some reason things didn't go well, then you can shut down; put the old 2TB drive back; and do a New Config with the "Parity is already valid" option box checked, and you'll be back to where you started.  This will only be true if you did NOT use the array during the rebuilding process.

 

Note, however, that even if you want to use the array, you can still replace the 8TB drive with the original 2TB drive if anything doesn't check out well => you just can't check the "Parity is already valid" checkbox in that case.

 

Thank you so much! for your experience and knowledge. This will help me a lot!

I feel more at ease now with what to do.

This will be a VERY nice upgrade => bumping your total capacity from 10TB to 16TB, and allowing easily growing to far more capacity with additional 8TB drives as needed ... up to a total of 40TB with no increase in the # of drives 

 

This will be a VERY nice upgrade => bumping your total capacity from 10TB to 16TB, and allowing easily growing to far more capacity with additional 8TB drives as needed ... up to a total of 40TB with no increase in the # of drives 

Yes, I was thinking the same thing. Buying the parity drive and the first drive seems expensive to only gain 6Tb, but now, I'll be set to expand to 40Tb like you say. I have a Lian Li case that is nice and compact but maxed out so I can't add, just exchange. When I first built this in 2010 I never thought I would see this same box hold 40TB or more!

Is this in a Q25B ??  (One of my favorite cases)

 

One of my servers is in the same case ... and I've been seriously thinking about doing EXACTLY what you just did.  It's currently populated with 3TB drives, and I still have a couple TB free ... but once it gets below 1TB of free space I'll likely do the same thing.

 

...and yes, the cost/TB is pretty high for the initial "jump", since you have to buy both a parity drive and a new data drive.  But once you have that 8TB parity, it makes expansion OH-so-nice 

 

Is this in a Q25B ??  (One of my favorite cases)

 

One of my servers is in the same case ... and I've been seriously thinking about doing EXACTLY what you just did.  It's currently populated with 3TB drives, and I still have a couple TB free ... but once it gets below 1TB of free space I'll likely do the same thing.

 

...and yes, the cost/TB is pretty high for the initial "jump", since you have to buy both a parity drive and a new data drive.  But once you have that 8TB parity, it makes expansion OH-so-nice 

 

I think it's actually a PC-V354B, which looks like the same size as the Q25B but has the grill in front along with a drive bay etc... I don't remember seeing the Q25B back in 2010, or I just overlooked it?

Just had a look => that's a very nice looking case.    Looks like a slightly larger version of the Q25B ... something close to the new PC-M25.  The front USB ports and optical drive bay are nice ... not needed for UnRAID, but certainly nice to have.

 

Just had a look => that's a very nice looking case.    Looks like a slightly larger version of the Q25B ... something close to the new PC-M25.  The front USB ports and optical drive bay are nice ... not needed for UnRAID, but certainly nice to have.

Yes, great cases. Built strong, finished off nice, and look great!

Just had a look => that's a very nice looking case.    Looks like a slightly larger version of the Q25B ... something close to the new PC-M25.  The front USB ports and optical drive bay are nice ... not needed for UnRAID, but certainly nice to have.

More like a larger version of the PC-Q08.