topic Re: CDOT 8.3.2 percent-used, percent-physical-used, and volume show-space in ONTAP Discussions

CDOT 8.3.2 percent-used, percent-physical-used, and volume show-space

SMLocke — Wed, 04 Jun 2025 15:06:32 GMT

This feels like it should be a very basic Storage Guy question that I should already know the answer to, but I'm not having a lot of luck so far.

A certain volume hit 93% usage, which threw an alert. By the time I looked at it, it was down to 90%, which is fine. It prompted me to look further into that volume though, and some numbers aren't adding up.

The volume hosts a handful of iSCSI LUNs. The percent-used value is still 90%. The percent-physical-used value is 20%. The volume show-space command shows 30% used (because of the +10% snapshot reserve). There's no snapshot spillover - I'm currently using less than half the reserve. What distinguishes one of the used percent values from another? How can I account for the difference?

Below is the output of the vol show -instance, and the vol show-space. Relevant items are highlighted. Thanks!

Vserver Name: [redacted]
Volume Name: [redacted]
Aggregate Name: [redacted]
Volume Size: 50TB
Volume Data Set ID: 1589
Volume Master Data Set ID: 2147485245
Volume State: online
Volume Type: RW
Volume Style: flex
Is Cluster-Mode Volume: true
Is Constituent Volume: false
Export Policy: default
User ID: 0
Group ID: 0
Security Style: unix
UNIX Permissions: ---rwxr-xr-x
Junction Path: -
Junction Path Source: -
Junction Active: -
Junction Parent Volume: -
Comment: [redacted]
Available Size: 4.71TB
Filesystem Size: 50TB
Total User-Visible Size: 45TB
Used Size: 9.87TB
Used Percentage: 90%
Volume Nearly Full Threshold Percent: 95%
Volume Full Threshold Percent: 98%
Maximum Autosize (for flexvols only): 50TB
(DEPRECATED)-Autosize Increment (for flexvols only): 100GB
Minimum Autosize: 38.76TB
Autosize Grow Threshold Percentage: 92%
Autosize Shrink Threshold Percentage: 50%
Autosize Mode: grow
Autosize Enabled (for flexvols only): true
Total Files (for user-visible data): 31876689
Files Used (for user-visible data): 166
Space Guarantee Style: none
Space Guarantee in Effect: true
Snapshot Directory Access Enabled: true
Space Reserved for Snapshot Copies: 10%
Snapshot Reserve Used: 43%
Snapshot Policy: 3dailys
Creation Time: Tue Apr 12 15:45:58 2016
Language: C.UTF-8
Clone Volume: false
Node name: [redacted]
NVFAIL Option: on
Volume's NVFAIL State: false
Force NVFAIL on MetroCluster Switchover: off
Is File System Size Fixed: false
Extent Option: off
Reserved Space for Overwrites: 0B
Fractional Reserve: 0%
Primary Space Management Strategy: volume_grow
Read Reallocation Option: off
Inconsistency in the File System: false
Is Volume Quiesced (On-Disk): false
Is Volume Quiesced (In-Memory): false
Volume Contains Shared or Compressed Data: true
Space Saved by Storage Efficiency: 11.38TB
Percentage Saved by Storage Efficiency: 54%
Space Saved by Deduplication: 1.72TB
Percentage Saved by Deduplication: 8%
Space Shared by Deduplication: 1.57TB
Space Saved by Compression: 9.66TB
Percentage Space Saved by Compression: 45%
Volume Size Used by Snapshot Copies: 2.15TB
Block Type: 64-bit
Is Volume Moving: false
Flash Pool Caching Eligibility: read-write
Flash Pool Write Caching Ineligibility Reason: -
Managed By Storage Service: -
Create Namespace Mirror Constituents For SnapDiff Use: -
Constituent Volume Role: -
QoS Policy Group Name: -
Caching Policy Name: auto
Is Volume Move in Cutover Phase: false
Number of Snapshot Copies in the Volume: 3
VBN_BAD may be present in the active filesystem: false
Is Volume on a hybrid aggregate: true
Total Physical Used Size: 9.83TB
Physical Used Percentage: 20%

[cluster]::> vol show-space [redacted]

Vserver : [redacted]
Volume : [redacted]

Feature Used Used%
-------------------------------- ---------- ------
User Data 9.70TB 19%
Filesystem Metadata 27.93GB 0%
Inodes 128KB 0%
Snapshot Reserve 5TB 10%
Deduplication 72.02GB 0%
Performance Metadata 72.03GB 0%

Total Used 14.87TB 30%

Total Physical Used 9.83TB 20%

Re: CDOT 8.3.2 percent-used, percent-physical-used, and volume show-space

robinpeter — Tue, 09 May 2017 01:40:27 GMT

Can you please run the follwing commands and paste the output.

which might help to clarify few things..

::> lun show -vserver <vserver> -volume <volume> -instance
::> df -S <volume>
::> df -r <volume>
::> snapshot show -volume <volume>

Robin.

Re: CDOT 8.3.2 percent-used, percent-physical-used, and volume show-space

SMLocke — Tue, 09 May 2017 13:13:54 GMT

Hoo boy that's a lot of text, but here you go, enjoy!

cluster::> lun show -vserver VSERVER -volume VOLUME -instance

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_D.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_D.lun
LUN Size: 300.0GB
OS Type: windows_2008
Space Reservation: enabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 299.6GB
Maximum Resize Size: 2.94TB
Creation Time: 4/14/2016 01:07:44
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_1
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_L.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_L.lun
LUN Size: 150.0GB
OS Type: windows_2008
Space Reservation: enabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 121.0GB
Maximum Resize Size: 1.47TB
Creation Time: 4/14/2016 01:07:44
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_1
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_E.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_E.lun
LUN Size: 150.0GB
OS Type: windows_2008
Space Reservation: enabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 39.74GB
Maximum Resize Size: 1.47TB
Creation Time: 9/15/2016 23:42:55
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_2
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_F.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_F.lun
LUN Size: 1.46TB
OS Type: windows_2008
Space Reservation: enabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 874.6GB
Maximum Resize Size: 14.71TB
Creation Time: 9/15/2016 23:42:56
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_3
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_M.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_M.lun
LUN Size: 6.35TB
OS Type: windows_gpt
Space Reservation: disabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 5.17TB
Maximum Resize Size: 15.97TB
Creation Time: 11/14/2016 15:50:40
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_3
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_N.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_N.lun
LUN Size: 3.42TB
OS Type: windows_gpt
Space Reservation: disabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 2.99TB
Maximum Resize Size: 15.97TB
Creation Time: 11/14/2016 15:51:06
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_3
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_S.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_S.lun
LUN Size: 1.00GB
OS Type: windows_2008
Space Reservation: enabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 11.60MB
Maximum Resize Size: 502.0GB
Creation Time: 9/15/2016 23:42:56
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_3
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_W.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_W.lun
LUN Size: 500.1GB
OS Type: windows_2008
Space Reservation: enabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 232.3GB
Maximum Resize Size: 4.90TB
Creation Time: 9/15/2016 23:42:56
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_4
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_L.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_L.lun
LUN Size: 1.46TB
OS Type: windows_2008
Space Reservation: disabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 1001GB
Maximum Resize Size: 14.71TB
Creation Time: 12/17/2016 04:01:50
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_4
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_M.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_M.lun
LUN Size: 6.35TB
OS Type: windows_gpt
Space Reservation: disabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 4.72TB
Maximum Resize Size: 15.97TB
Creation Time: 12/17/2016 04:02:05
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_4
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_O.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_O.lun
LUN Size: 4.40TB
OS Type: windows_gpt
Space Reservation: disabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 3.43TB
Maximum Resize Size: 15.97TB
Creation Time: 12/17/2016 04:02:17
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_4
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_Q.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_Q.lun
LUN Size: 1.00GB
OS Type: windows_2008
Space Reservation: enabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 11.57MB
Maximum Resize Size: 502.0GB
Creation Time: 9/15/2016 23:42:57
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_4
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_P.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_P.lun
LUN Size: 700.0GB
OS Type: windows_2008
Space Reservation: enabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 46.48GB
Maximum Resize Size: 1.96TB
Creation Time: 9/15/2016 23:42:57
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_5
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false

Vserver Name: VSERVER
LUN Path: /vol/VOLUME/REDACTED_R.lun
Volume Name: VOLUME
Qtree Name: ""
LUN Name: REDACTED_R.lun
LUN Size: 600.0GB
OS Type: windows_2008
Space Reservation: enabled
Serial Number: REDACTED
Serial Number (Hex): REDACTED
Comment:
Space Reservations Honored: false
Space Allocation: disabled
State: online
LUN UUID: REDACTED
Mapped: mapped
Block Size: 512
Device Legacy ID: -
Device Binary ID: -
Device Text ID: -
Read Only: false
Fenced Due to Restore: false
Used Size: 59.06GB
Maximum Resize Size: 1004GB
Creation Time: 9/15/2016 23:42:57
Class: regular
Node Hosting the LUN: CLUSTER-05
QoS Policy Group: QOS_5
Clone: false
Clone Autodelete Enabled: false
Inconsistent import: false
14 entries were displayed.

cluster::>
cluster::>
cluster::> df -S VOLUME
Filesystem used total-saved %total-saved deduplicated %deduplicated compressed %compressed Vserver
/vol/VOLUME/ 10512136344 12381963928 54% 1848242360 8% 10533721568 46% VSERVER

cluster::>
cluster::> df -r VOLUME
Filesystem kbytes used avail reserved Mounted on Vserver
/vol/VOLUME/ 48318382080 10512242360 5745788364 0 --- VSERVER
/vol/VOLUME/.snapshot 5368709120 1579221768 3789487352 0 --- VSERVER
2 entries were displayed.

cluster::> snapshot show -volume VOLUME -fields size
vserver volume snapshot size
------------- ------------------ -------------------------- -------
VSERVER VOLUME daily@0500.2017-05-07_0334 341.9GB
VSERVER VOLUME daily@0500.2017-05-08_0334 607.6GB
VSERVER VOLUME daily@0500.2017-05-09_0334 556.9GB
3 entries were displayed.

cluster::> lun show -vserver va01vs_dmcs_p -volume dmcs_p_lun_high_01 -fields size,size-used
vserver path size size-used
------------- ------------------------------------- ----- ---------
VSERVER /vol/VOLUME/REDACTED.lun 300GB 299GB
VSERVER /vol/VOLUME/REDACTED.lun 150GB 121GB
VSERVER /vol/VOLUME/REDACTED.lun 150GB 39GB
VSERVER /vol/VOLUME/REDACTED.lun 1500GB 874GB
VSERVER /vol/VOLUME/REDACTED.lun 6500GB 5297GB
VSERVER /vol/VOLUME/REDACTED.lun 3500GB 3061GB
VSERVER /vol/VOLUME/REDACTED.lun 1GB 0GB
VSERVER /vol/VOLUME/REDACTED.lun 500GB 232GB
VSERVER /vol/VOLUME/REDACTED.lun 1500GB 1001GB
VSERVER /vol/VOLUME/REDACTED.lun 6500GB 4831GB
VSERVER /vol/VOLUME/REDACTED.lun 4505GB 3513GB
VSERVER /vol/VOLUME/REDACTED.lun 1GB 0GB
VSERVER /vol/VOLUME/REDACTED.lun 700GB 46GB
VSERVER /vol/VOLUME/REDACTED.lun 600GB 59GB
14 entries were displayed.

cluster::>
cluster::>
cluster::>
cluster::> vol show VOLUME
Vserver Volume Aggregate State Type Size Available Used%
--------- ------------ ------------ ---------- ---- ---------- ---------- -----
VSERVER VOLUME AGGR online RW 50TB 5.35TB 89%

cluster::>
cluster::> vol show-space VOLUME

Vserver : VSERVER
Volume : VOLUME

Feature Used Used%
-------------------------------- ---------- ------
User Data 9.58TB 19%
Filesystem Metadata 27.85GB 0%
Inodes 128KB 0%
Snapshot Reserve 5TB 10%
Deduplication 46.04GB 0%
Temporary Deduplication 67.07GB 0%
Performance Metadata 70.68GB 0%

Total Used 14.79TB 30%

Total Physical Used 9.07TB 18%

cluster::>

My thoughts upon looking at the above:

The sum of all snapshots is 1506GB, which is less than the snapshot reserve of 5120GB.
Some LUNs are thin provisioned and some aren't. The correct sum of LUNs, near as I can tell, is 21605GB (i.e., the LUN size of thick LUNs plus the used size of thin LUNs)
That sum of LUNs (21605) and the snapshot reserve (5120GB) is 26725GB, or about 52% of the total volume (51200GB). That percentage value doesn't align to any other figure present, so maybe I'm mistaken there.
I may not have a clear idea of how dedupe and compression interact with any of the "used percentage" figures CDOT coughs up.

Re: CDOT 8.3.2 percent-used, percent-physical-used, and volume show-space

robinpeter — Tue, 09 May 2017 16:07:01 GMT

I havn't looked at everything.. just starting my day in west-cost.

You have few thick provisioned lun in a thin provisioned volume, that might be the reason for this reporting...

Even though you created 50TB volume, that space is not reserved for that volume from aggr until its used by it.

Volume:

Space Guarantee Style: none

LUN:

Space Reservation: enabled

My Suggestion, It might help you understand this lil better if you read about

Storage Efficiency

Space Guarantee

Fractional Reserve,

Space Reserve &

Space Allocation.

robin.

Re: CDOT 8.3.2 percent-used, percent-physical-used, and volume show-space

SMLocke — Tue, 09 May 2017 16:58:26 GMT

Right, yep, a couple of thick provisioned LUNs in a thin provisioned volume, which isn't ideal, but it's what I've got.

So, if I've tallied everything correctly that should be present, I have something like:

3902GB of thick provisioned LUNs (lun show -volume VOL -space-reserve enabled -fields size)
17703GB of used capacity in thin provisioned LUNs (lun show -volume VOL -space -reserve disabled -fields size-used)
5120GB of snapshot reserve (less than 100% of which is used)

This sums to 24433GB, which is 47.7% of the 51200GB volume. That figure doesn't align with any other percentage figure I can summon from the NetApp:

89% used, 10009GB used, 9378GB physical-used, 5230GB available (vol show VOL -fields size,used,percent-used,available,physical-used)
30% total used (15129GB used, which aligns w/ 10009GB "used" from previous command + 5120GB snapshot reserve) (vol show-space VOL)

The real outlier here is that big 89% used value. How can I be using 15129GB/51200GB and that shakes out to 89% usage? Is it all down to "something weird" about having thick provisioned LUNs inside a thin provisioned volume? Is it worth opening a ticket to NetApp to confirm?

Re: CDOT 8.3.2 percent-used, percent-physical-used, and volume show-space

robinpeter — Tue, 09 May 2017 17:19:24 GMT

"The real outlier here is that big 89% used value. How can I be using 15129GB/51200GB and that shakes out to 89% usage? Is it all down to "something weird" about having thick provisioned LUNs inside a thin provisioned volume? Is it worth opening a ticket to NetApp to confirm?"

Feel free to open the ticket.. if they can find a different answer.. keep us updated.

Simple answer is.. your volume DONT have 51200GB until you write that much data to it... again.. because, your volume is thin provisioned.

So just tallying the number against 51200GB dont work while you have a thin provisioned volume.

Re: CDOT 8.3.2 percent-used, percent-physical-used, and volume show-space

aborzenkov — Tue, 09 May 2017 19:26:54 GMT

How much free space on aggregate? Volume cannot have more space available than containing aggregate.