Ok... I'm new to UnRaid, and finally have my server up and running... I think.

 

I have 2x 2TB data drives and 1X1TB parity drive.

 

I have set up user shares for several different purposes. Here's the general layout:

 

\\tower\Acronis with sub directories for each machine's backups

\\tower\Files with sub directories for different file type (installs, shared files, etc.)

\\tower\Media with sub directories for BluRay, DVD, TvShows, Music and so on

 

 

So far I have close to 30 gig in movies in the Media share, 30 gig in the Files share, and 60 gig in the Acronis share.

 

What is confusing me is that when I look at the state of my UnRaid box, Disk 1 is taking all the data while Disk 2 has not been touched since I started the array (only reporting 10 writes). Is this how it should be? I expected the data to be spread across the disks. I left the shares with the default settings when I created them.

 

If Disk 1 fails in the current setup, is that data just gone? I ran a parity check and it checks OK, but I just don't understand how it could be rebuilt with absolutely no writes to disk 2.

I assume there is a typo somewhere, since it is not possible to have a 1TB parity drive with 2TB data drives.

 

The default share configuration is High-Water, meaning it will write to a disk until half of the freespace is used, then switch to writing to another disk. You really should read this Configuration Tutorial completely.

 

As for losing a disk, if you have good parity and all of the other drives are good, you can rebuild it.

I believe hat the default allocation method for a share is 'high-water' which means that a disk is half filled before the next disk starts being used so the behaviour you are seeing is normal.  If you want more information on the details of the different allocation methods read the wiki.

 

As to what happens if disk 1 ails, you WILL be able to recreate it from the combination of disk 2 plus parity.    When parity was calculated it took into account the current state of disk 2 so the fact no files are currently on it does not invalidate the ability to recreate a disk.  In fact parity has no concept of files anyway - it works at the disk physical sector level which is one of the reasons that the parity drive can never be smaller than any of the data drives.

Yes... there was a typo, it's a 2TB parity.

 

That makes sense. I'm just so used to the stripe world that I'm having a hard time wrapping my head around this

 

I like to think of it as parity without putting all my data at risk for the sake of achieving parity, in a cost effective and flexible manner.