Hello all.  I recently decided to start my first unRAID server after looking into a variety of NAS options for a few weeks.

 

It is built off of an old PC that I originally built in 2008, and had lying around doing nothing, so it was a fairly cheap NAS to get going (Just had to buy a few drives and the unRAID license to get started).

 

I started everything up, got through my initial parity check and started the array.

 

Currently I am copying data off of my desktop and onto a 2TB data disk.  Once this completes, I will pull the 1.5TB disk from my PC, and add it to the array.  I will proceed in this fashion with another 1TB, and a 750GB disk in my PC until they are all in the array, giving me 3TB Parity, 2TB, 1.5TB, 1TB, 750GB.  This will be ongoing for the next few days until all drives are copied across.

 

This brings me to my first question.

 

I am seeing a number of posts and recommendations for pre-clearing the drives before adding them to the array, but I cannot tell if this stands for v6.  I did not Pre-Clear the 3TB parity or the 2TB data disks that I currently have installed.  They went through the format that unRAID forced upon mounting them, but that was it.

 

Should I be pre-clearing the drives before adding to the array?

 

2nd Question - I am planning on using a 250GB SSD as a cache disk.  Should I wait to mount this until after my initial data copy to the array?  Based on my understanding of how the cache would work, When I save data to the array, it writes to the cache, and stays there until a specified time (3:40am) when it is copied to the data disks, and wiped from the cache.  I dont imagine this would work properly when I am copying 1TB of data at a time.  But, please let me know if it would, Im looking at 4 or 5 days of non-stop data copying at this point (only getting 11 mb/s transfer) and if cache disk can work and speed up this process, I would plug it in today.

 

 

Appreciate the help, and I look forward to being a part of this awesome community!

 

Further specs if there are any questions...(woohoo 2008 hardware!)

 

2x2GB DDR2 SDRAM

BIOSTAR A770 Motherboard

AMD Phenom 9850 Black Quad Core 2.5 Ghz CPU

hec HP585DB 585W ATX12V Power Supply

 

Drives

3TB WD Red (Parity)

2TB WD Blue

1.5 TB WD Green

1TB Seagate Barracuda

750 GB WD Caviar

250 GB Samsung EVO SSD

 

 

 

1) There isn't anything to preclear after you have formatted the whole drive really.

2) Yes, you should enable a cache drive only after you put your initial data on the array. Even more, if you are copying your data and thus have a backup (the original place) during transfer, disable parity disk too. Enable it after the transfer is complete.

Writes directly to disks are never cached. Only writes to user shares that have been set to Use cache: Yes.

 

unRAID only requires a clear disk if you are adding it to a new slot in an array that already has parity built. A clear disk is all zeros and so parity will remain valid when you add a clear disk. If you don't preclear a disk when unRAID requires a clear disk, it will clear the disk.

 

Many recommend preclearing a disk to test it anyway, and to eliminate infant mortality. If the disks aren't new and you know they are OK (have you actually checked their SMART attributes?) then it is probably OK to go ahead and use them.

 

Be aware though that just because Windows never complained about a disk doesn't mean it doesn't have problems. All bits of all disks must be trustworthy because all bits of all disks will be required if one needs to be rebuilt.

 

Post a diagnostic if you want us to check your disks SMART for you.

 

And one other thing, parity disk is not formatted because it doesn't have a filesystem. Many people have a very vague notion of what formatting a disk is, just something that is done to a disk to get it ready to use.

 

Format actually means "write an empty filesystem to this disk". That is what it has always meant on every operating system you have ever used.

Thanks.

 

I am writing to user shares.  I do not have cache enabled at this time because of the concerns I explained.  So, I am still assuming that I should not use Cache until after my initial data transfer.

 

Thank you for the clarification on the Pre-Clear.  I was unaware of the pre-clear checking to ensure the disk is fully healthy.  I have never had any issues with the 3 disks I am moving from my PC to the unRAID, but I will pre-clear them to be safe.  I did not pre-clear the first disk in the array, so fingers crossed it was ok out of the box (brand new bare disk).

 

Appreciate the help.

So I ran a SMART via command prompt (wmic diskdrive get status) and CrystalDiskInfo.  I have attached the reports that I got from them...I recieved a "Caution" on 2 of the disks I planned on moving to my array.  WMIC came up clean.

 

Can someone check the attached images and let me know if these will be OK to use in the array?  Or is there a better SMART report I can run (apart from pre-clear obviously).

 

Appreciate any help.

 

So I ran a SMART via command prompt (wmic diskdrive get status) and CrystalDiskInfo.  I have attached the reports that I got from them...I recieved a "Caution" on 2 of the disks I planned on moving to my array.  WMIC came up clean.

 

Can someone check the attached images and let me know if these will be OK to use in the array?  Or is there a better SMART report I can run (apart from pre-clear obviously).

 

Both have issues, and considerable age.  I would not add them until you have Precleared them 2 or 3 times, and they have passed every time.

That was my thought as well...

 

Thanks for confirming.

For future reference, you can get the SMART for any disk in the unRAID webUI by clicking on the disk. And Tools - Diagnostics will let you download a zip containing syslog, SMART for all, and other useful things.