Total disc size??

[industrialarts]

I finally got UNRAID up and running to test.  I had two 40G hard drives to play with.  When I look at the properties in Windows explorer for the new drive (Tower/disk1) I have mapped, it shows the total space to be 40G.  Huh?  I expected to have the 80g minus the space for parity.  I can find no info in the forums or documentation in reference to this.

 

Could someone please explain how this works?

 

Thanks

 

industrialarts

[cmhardwick]

Disk1 is ONE physical disk, so 40gb is correct. The parity will not show as a share.

 

If you had both 40gb drives configured as data drives (no parity) and had a directory on each drive called MOVIES for instance then, in windows, after updating user shares and making sure they are being exported, you would see the following

 

Tower/disk1 (properties would show 40gb)

Tower/disk2 (properties would show 40gb)

Tower/MOVIES (properties would PROBABLY only show about 40mb. This is just the ramdisk that is used to make the share, on 2 physical locations, look like one drive).

[industrialarts]

Thanks, but I still am not sure just how drive space is calculated.  For example, if I have 3 500G drives, does that make 1T of storage?

 

 

industrialarts

[Joe L.]

Simple answer. 

 

To protect your  data, you need one parity drive, regardless of the number of data drives.

Nothing is stored on the parity drive except for parity.  Therefore, you do not add its capacity to your data total.

 

So, with 2 500Gig drives, one would be available for data, one for parity.  Total storage for your data = 500 Gig.

 

With three 500 Gig drives, two would be available for data, and one used for parity. Total storage for data = 1000 Gig.

 

Add one more 500 Gig drive and now  three would be available for data, and one used for parity. Total storage for data = 1500 Gig.

 

Now, lets say you get a great deal on a 750 Gig drive, but the sale is limited, one to a customer.  It you attempt to install it in you unRaid array as a data drive it will complain and not start, stating that the new drive is larger than your parity drive.  You must therefore assign it as the parity drive and assign the old parity drive as a data drive. 

 

Now, you would have one 750 Gig drive for parity, and 4 500 Gig data drives, for a total data capacity of 2000 Gig.

 

If at a later date you find another 750 Gig drive on sale, you can add it as a data drive, now 2750 Gig total is available for your data. (4 500 Gig drives and a single 750 Gig drive)

 

Joe L.

[industrialarts]

Got it - Thanks!