Allocated Space: 99% for all disks – could it be a concern?

Note: We do not use scheduled snapshot (replay profile) or any advanced features

Hello darienwu,

Looking at the screen shots that you posted I can see that you have 1.81TB of free space left on your SCv2020.  You will start getting alerts that you are running out of space at 10% space left, as that is what the threshold is set to.  You will need to add more drives to get more space before you run out of free space.

Please let us know if you have any other questions.

I am not a big fan of looking at space usage under the disk folder. I feel this does not always show the full picture. I would suggest to follow the steps on page 315 of the Dell Storage Manager 2016 R3 Administrator’s Guide:
For each storage type, the data progression pressure report displays how space is allocated, consumed, and scheduled to move across different RAID types and storage tiers. Use the data progression pressure report to make decisions about the types of disks to add to a Storage Center.
1. Select a Storage Center from the Storage view. (Data Collector connected Storage Manager Client only)
2. Click the Storage tab.
3. In the Storage tab navigation pane, expand Storage Type, then select the individual storage type that you want to examine.
4. Click the Pressure Report subtab to view the data progression pressure report. By default, the most recent data gathered from the Storage Center is displayed.
5. (Optional) To view a previously generated data progression report, select a report from the drop-down menu. Reports are identified by the date and time at which they were generated.

Disk Space Available - Total amount of disk space available on the disks of a Storage Center
Disk Space Allocated - Total amount of disk space allocated on the disks

Disk Allocated - Space reserved for volumes.
Disk Used - From the amount of space allocated, the amount that is in use by volumes.

Volume Allocated - Amount of space reserved for use by volumes after RAID is applied.
Volume Used - Amount of space used by volumes after RAID is applied.
I feel this can give you a better view of what is allocated, used, and available.

https://topics-cdn.dell.com/pdf/storage-sc2000_administrator-guide_en-us.pdf

Hi Bob,

Please find the Pressure Report and related screenshots as follows. I would appreciate it if you could take a look at this other question as well since I believe both are correlated and a part of the question is better suited to the subject there: 

https://www.dell.com/community/Compellent/Why-RAID10-is-allocated-when-only-Efficiency-profile-is-used/m-p/6208542#M2521

Hi Darren,

I have a similar scenario where 2 (7K disks, and 15K disks) out of 3 tiers of disks shows as 99% fully allocated while I am using 50% of my actual space.  Like you, I would like to know:

• Is it a concern?
• Is that normal behavior?
  I have all profiles set to use the Dell Recommended profile so I have not "allocated" space directly to a tier or specific disk type.  So what is allocating to my 15K and 7K disks?
• Is performance being affected?
  (is my 15K disks still being used to write/read frequently used data)
  (is the system still 'archiving' old data to tier 3 - the progression report would show this I'm sure)

I have a feeling that since you gave Kudos to Bob he may not come back to read your post again :(

Hello Andrew_P76,
Actually in another post I sent a private message to Darien to work with him on his concerns.
https://www.dell.com/community/Compellent/Why-RAID10-is-allocated-when-only-Efficiency-profile-is-used/m-p/6208542#M2521

In your case I suspect you had migrated data from another system, or recently added new data. New data is written to Tier 1 and then moved down over time. The system looks at data as it is imported, or written and tries to determine how much space is needed. Then as no new data is added the system will then remove older allocated space.

•Is it a concern?
Answer: No
•Is that normal behavior?
I have all profiles set to use the Dell Recommended profile so I have not "allocated" space directly to a tier or specific disk type.  So what is allocating to my 15K and 7K disks?

Answer: The system tries to determine space usage based upon recently added data. If a large amount of data is added at once ther system "thinks" this much space will be added on a consistent basis so it make more allocated space available

•Is performance being affected?
(is my 15K disks still being used to write/read frequently used data)
(is the system still 'archiving' old data to tier 3 - the progression report would show this I'm sure)

Answer: No, as long as there is free space to write to there is no performance impact. If Tier 1 runs out of space to write to then it could impact performance as all data writes will go to Tier 3 which has slower disks.

If you want to open a case to remove some allocted space please send me a private message to work with you on this.