How I can Understund the space allocation on FreeNAS

[PCorsetti]

Hi,

From few days I have received the duties to manage two FreeNAS server, unfortunately I don't have people to ask information about the configuration setting.

I need help to understand how the space has been allocated on FreeNAS configuration.

I have a System with 6 HDD from 3.64TB for more o less 20TiB of space, the pools give me information that the pools has been used for 5.16 TiB (49%) and I have 5.38 TiB free.

I report the pools information below because I have difficult to attach the files.
Pools

vol1_raidz10_freenas1 HEALTHY(5.16 TiB (49%) Used / 5.38 TiB Free)
settings
Name Type Used Available Compression Compression Ratio Readonly Dedup Comments
vol1_raidz10_freenas1 dataset 5.16 TB 5.38 TB lz4 1.95x false off
iscsi_1 zvol 5.16 TB 9.18 TBInherits (lz4) 1.95x false off

I don't understand where the space is allocated and used.

The space used is the same on the first raw (vol1xxxxxx of type dataset) and for the second raw iscsi_1 type zvol but the available space are different, can you explain me what means this?

How I can check where is configured the remaining spaces or where I can found free spaces that need to be configured?

Can you help me to understand how read the FreeNAS conguration?

 

[dlavigne]

It's really hard to read your usage output (please use code tags to format the output of zpool status).

 

[PCorsetti]

It's really hard to read your usage output (please use code tags to format the output of zpool status).

I put the images of the information that FreeNAS give me :

Zpool list command output

df -h command output

These are the information about the system:

We have 6 disk from 3.64 TiB for a total of 21,84 TiB as you can see:

we have on the system a pool defined as follow:

Summary:

1) I have a total of 21TiB

2) I have a pool that:

the command zpool list tell me that has been defined a pool vol1_raidz10_freenas1 of 10.9 TiB

the FreeBUS gui console tell me that the pool vol1_raidz10_freenas1 has been defined 5.16 TiB

(which information is true)

3) we have defined iscsi space and I don't understand if this space need to add to the space of the pool vol1_raidz10_freenas1

4) I don't understand if we have unallocated space on the system

 

[sretalla]

2) I have a pool that:

the command zpool list tell me that has been defined a pool vol1_raidz10_freenas1 of 10.9 TiB

the FreeBUS gui console tell me that the pool vol1_raidz10_freenas1 has been defined 5.16 TiB

(which information is true)

10.9 TiB is the total... you're using 5.16 TiB, leaving 5.38 TiB free just like it says... allowing for a little rounding in there.

3) we have defined iscsi space and I don't understand if this space need to add to the space of the pool vol1_raidz10_freenas1

4) I don't understand if we have unallocated space on the system

I can't tell you anything about what's going on if you don't share the output of zpool status as asked by @dlavigne already.

 

[PCorsetti]

10.9 TiB is the total... you're using 5.16 TiB, leaving 5.38 TiB free just like it says... allowing for a little rounding in there.
Yes the output is clear but I don't found the same information using du -sh command.
As you can see the pool vol1_raidz10_freenas1 is empty

I suppose that 5,16 TiB are used by iscsi_1 but don't understand how to verify this.

Another information that is not clear is that if I sum for iscsi_1 the space used and available I obtain 14 TiB that is grather than 10.9 TiB of the pool vol1_raidz10_freenas1
I don't understand how to read this information.

I can't tell you anything about what's going on if you don't share the output of zpool status as asked by @dlavigne already.

This is the output of zpool status

 

[sretalla]

So with Mirrored VDEVs in your pool, it's perfectly normal to lose half the capacity to parity/mirroring. (that explains how you get from 21 to 10.9)

There seems to be no spare capacity in the system as I see it.

The discrepancy you're seeing is related to the compression ratio... You see that you're getting a compression ratio of almost 2 in your zvol... this means you can fit nearly twice the bits on it as are available on the disks themselves... hence showing more free space than you really have (on the assumption that the ratio continues to remain at that level).

I think that should now solve the mysteries of it all.

 

[sretalla]

Maybe just to help a little more... zvols aren't logically stored in the same place as they are physically stored.

Look inside /dev/zvol and you should find the file itself that's taking the space as reported in the GUI.

 

[PCorsetti]

So with Mirrored VDEVs in your pool, it's perfectly normal to lose half the capacity to parity/mirroring. (that explains how you get from 21 to 10.9)

There seems to be no spare capacity in the system as I see it.

The discrepancy you're seeing is related to the compression ratio... You see that you're getting a compression ratio of almost 2 in your zvol... this means you can fit nearly twice the bits on it as are available on the disks themselves... hence showing more free space than you really have (on the assumption that the ratio continues to remain at that level).

I think that should now solve the mysteries of it all.

Thanks for your help.

Sorry for later answers, but I was busy with a critical issue.

Ok for the Total space.
You tell me that with zpool status I can see the raid 1 configuration.
If I analyze the zpool output I have three disk mirrored ( 0 - 1 - 2) that are added into the pool and is normally that we have available only half of total space.

Now, when we define a pool we assign a space and we can use the space as we want.
If we define a iscsi space it use the pool space.

How I can verify the space used by iscsi process?

 

[PCorsetti]

Maybe just to help a little more... zvols aren't logically stored in the same place as they are physically stored.

Look inside /dev/zvol and you should find the file itself that's taking the space as reported in the GUI.

Follows the list of the files on /dev/zvol but I don't understand how to read it.

I see that we have a pool defined as directory vol1_raidz10_freenas1 and iscsi_1 as a special connector