Trying to understand disk usage

[TheSJDRising]

Hi there

 

Currently evaluating Unraid to replace my aging Windows Home Server box. It seems great and it ticks the boxes and I think I'm going to go ahead with a license, but I'm struggling with the 'disk used' column in the 'Main' tab. 

 

As a point of order I've a simple setup. 2x14TB WD Reds in my new server - one as a data disk and one as a parity disk (parity still building). I've setup one Windows 10 VM but haven't stored any other data on the server other than the Windows install ISO.

 

It seems that the 'Used' column is counting all my data twice - once under the User Share, and once under the Disk Share. I haven't setup any disk shares on the server, and they're set to auto in the Global Shares settings. Even if I set the Disk share setting to 'No' and restart the array the issue persists. If I look at the terminal I can confirm this usage:

 

root@NAS:/mnt# du -h | sort -n
0       ./disk1/appdata
0       ./user/appdata
1.0G    ./disk1/system/libvirt
1.0G    ./user/system/libvirt
5.5G    ./disk1/isos
5.5G    ./user/isos
20G     ./disk1/system/docker
20G     ./user/system/docker
21G     ./disk1/system
21G     ./user/system
24G     ./disk1/vms
24G     ./disk1/vms/Atlas
24G     ./user/vms
24G     ./user/vms/Atlas
50G     ./disk1
50G     ./user
100G    .

 

So my 'Used' column is showing 151GB of data, despite my only having a 40GB thin provisioned VM, the 20GB docker file, the 5.5GB Windows ISO and a few other system bits and pieces. 

 

Please help!?

 

Thanks

 

Simon

Edited March 30, 2020 by TheSJDRising
Typo

[trurl]

The user shares are just another view of the disks, but it is a view which spans disks. Each top level folder across all disks in the array or cache pool is a user share. Top level folders with the same name are in the same user share. 

 

For most purposes you should just work with the user shares and not worry about the individual disks.

[TheSJDRising]

Thanks trurl and thanks for taking the time to reply.

 

I understand what you're saying about the user shares and how they span the disks. That definitely all makes sense.  However, my concern is that my disk1 will show as full when I've got only about 7TB of data on in it?

Edited March 30, 2020 by TheSJDRising

[TheSJDRising]

I should also say - I"m seeing the same thing on the main dashboard. It's saying the Array has 151GB of 14TB used already in the Array area of the dashboard.

 

My user shares are all incorrectly reporting their free space too...

Edited March 30, 2020 by TheSJDRising

[testdasi]

56 minutes ago, TheSJDRising said:

I should also say - I"m seeing the same thing on the main dashboard. It's saying the Array has 151GB of 14TB used already in the Array area of the dashboard.

You need to take a screenshot of your dashboard because I have never seen any issue with free space / used space counting by Unraid.

I think it's more likely than not that you misunderstood the information provided.

 

With regards to the du command, you used it incorrectly.

Think of /mnt/user as a bind mount that join up your various /mnt/diskx.

So by doing a du on /mnt, you are double counting the bind mount + the original data.

It has zero implication to how Unraid would understand the used/free space.

[Squid]

3 hours ago, TheSJDRising said:

40GB thin provisioned VM,

Should also be noted that the VMs while are technically thin provisioned, will always grow in size and never shrink unless you do this

 

[trurl]

3 hours ago, TheSJDRising said:

2x14TB WD Reds in my new server - one as a data disk and one as a parity disk

You have 14TB data, and 14TB parity. Parity is not data storage. All 14TB it is showing are from that single 14TB data disk.

[trurl]

Each additional data disk you add will be additional data capacity. If you add another parity disk (up to 2 are allowed) it won't give any additional storage, but it will provide additional redundancy.

 

Each parity disk must be at least as large as any single data disk. So, you can add a lot more disks, each up to 14TB, and they will have parity protection from that single parity disk. Single parity allows recovery of a single data disk, dual parity allows recovery of 2 data disks.

 

Take a look at this wiki overview for a better idea of how parity works, how user shares work, and many other things about Unraid features:

 

https://wiki.unraid.net/UnRAID_6/Overview