Pools, aggregates, and common provisioning groups

View the information that is shown about pools, aggregates, and common provisioning groups in block storage systems.

To view information about the pools, aggregates, or common provisioning groups that are associated with a storage system, click Pools, Aggregates, or Common Provisioning Groups. The type of the storage system determines which of these components can be viewed.

A storage pool is a grouping of storage that consists of volumes, logical unit numbers (LUNs), or addresses that share a common set of administrative characteristics.

An aggregate is a collection of physical disks or partitions arranged into one or more RAID arrays (NetApp RAID groups).

A common provisioning group is a user-defined pool of storage space on a HPE 3PAR StoreServ Storage system.

Tip: To see the information about all of the block storage pools in your data center, click Resources > Pools. If you are in the modern UI of IBM Storage Insights, click Main menu, expand Inventory, click Pools.
Special considerations for particular storage system models:
Pure FlashArray//M and FlashArray//X
While Pure storage systems do not have the concept of pools, a pool is displayed to maintain consistency in the IBM Storage Insights data model and to correctly display relationships between storage components.
SAN Volume Controller / Storwize V7.4 and later
These storage systems have the capacity to define parent and child pools. A parent pool has all the capabilities and functions of a normal SAN Volume Controller / Storwize pool. A child pool is a logical sub division of a storage pool or managed disk group. Like a storage pool, a child pool supports volume creation and migration, but the user can specify the capacity of the child pool at creation.
  • A child pool inherits its tier setting from the parent pool. Changes to a parent's tier setting are inherited by child pools. Changes to a child pool are applied to the parent pool and inherited by other siblings.
  • A child pool supports the Easy Tier® function if the parent pool has Easy Tier enabled. The child pool also inherits Easy Tier status, pool status, capacity information, solid state status, and back-end storage information. The activity of parent pool and child pool are the same since the volumes from the child pool reside on the parent pool.
The following information is shown for each pool:
Restriction: Definitions are provided only for column headings that might require more information to understand the values that are shown in the table.
Tip: To see information that is not shown by default in the table, right-click a column heading and select the information that you want to be shown.
Acknowledged
Shows whether a user marked the status of a pool as acknowledged. An acknowledged status indicates that the status was reviewed and is either resolved or can be ignored. An acknowledged status is not used to determine the status of related, higher-level resources.
For example, if a pool has an error status, the related storage system also shows an error condition. If the error status of the pool is acknowledged, it changes to Error-Acknowledged. This acknowledged status is then treated as normal, and is used in evaluating the overall condition of the storage system. In this case, if the other internal resources of the storage system are also normal, the storage system condition is considered normal.
Activity

Shows the activity level of pools. For pools on storage systems other than XIV systems and IBM Storage Accelerate, the activity level is set to the following value:


[Read I/O Rate × (1 − Read I/O Cache Hit %)] ÷ Total Pool Capacity

The activity level of pools on XIV systems and IBM Storage Accelerate is set to the following value:


(Total I/O Rate ÷ Total Capacity)
Adjusted Used Capacity (%)

The amount of capacity that can be used without exceeding the capacity limit.

Adjusted Used Capacity

The formula for calculating Adjusted Used Capacity (%) is (Used Capacity in GiB/Capacity Limit in GiB )*100. For example, if the capacity is 100 GiB, the used capacity is 40 GiB, and the capacity limit is 80% or 80 GiB, then the value for Adjusted Used Capacity (%) is (40 GiB/80 GiB )* 100 or 50%. So, in this example, you can use 30% or 40 GiB of the usable capacity of the resource before you reach the capacity limit.

If the used capacity exceeds the capacity limit, the value for Adjusted Used Capacity (%) is over 100%.

To add the Adjusted Used Capacity (%) column, right-click any column heading on the Pools page.

See these related values for more information Capacity Limit (%) and Capacity-to-Limit (GiB).

Availability: This metric is not available for all storage systems, such as Dell EMC VMAX.
Available Capacity (GiB)
(Previously known as Available Pool Space) The amount of physical space that is available in the pool. If the pool is a parent pool, the amount of space that is used by the volumes in the child pools is also included.
Availability: All storage systems. For IBM FlashSystem A9000 and IBM FlashSystem A9000R, this value represents provisioned capacity rather than physical space.
Available Repository Capacity (GiB)
The available, unallocated storage space in the repository for Track Space-Efficient (TSE) thin-provisioning.
Availability: DS8000 thin-provisioned pools.
Available Soft Capacity (GiB)
The amount of virtual storage space that is available to allocate to volumes in a storage pool.
Availability: XIV systems, and IBM Storage Accelerate storage systems.
Available Volume Capacity (GiB)
(Previously known as Effective Unallocated Volume Space) The total amount of remaining capacity that can be used by the existing volumes in the pools. The following formula is used to calculate this value:
Provisioned Capacity − Used Capacity
The capacity that is used by thin-provisioned volumes is typically less than their provisioned capacity. Therefore, the available capacity represents the difference between the provisioned capacity and the used capacity for all the volumes in the pool. For Hitachi VSP non-thin provisioned pool capacity, the unused volume capacity is always zero.
Availability: All storage systems, except IBM FlashSystem A9000 and IBM FlashSystem A9000R.
Available Written Capacity (GiB)
(Previously known as Effective Used Capacity) The amount of capacity that can be written to the pools before inline compression is applied. If the pools are not compressed, this value is the same as Available Capacity.
Important: Because data compression is very efficient, a pool can run out of Available Written Capacity while physical capacity is still available. To stay aware of your capacity needs, monitor this value and Available Capacity.
Back-End Storage Disks
The number of physical disks that contribute to the volumes on the back-end storage system. Available only for pools on storage systems that run IBM Storage Virtualize.
If the back-end storage system was not probed, then the value in this column is blank. To manually define the number of disks to help calculate the approximate read I/O capability of the pool, right-click a pool in the list and select View Properties. On the Back-end Storage tab in properties notebook, click Edit.
Back-End Storage Disk Type
The class and speed of the physical disks that contribute to the volumes on the back-end storage system. Available only for pools on storage systems that run IBM Storage Virtualize.
If the back-end storage system was not probed, then the value in this column is blank. To manually define a disk type to help calculate the approximate read I/O capability of the pool, right-click a pool in the list and select View Properties. On the Back-end Storage tab in properties notebook, click Edit.
Back-End Storage RAID Level
The RAID level of the volumes on the back-end storage system that are providing storage space to a pool. Available only for pools on storage systems that run IBM Storage Virtualize.
If the back-end storage system was not probed, then the value in this column is blank. To manually define a RAID level to help calculate the approximate read I/O capability of the pool, right-click a pool in the list and select View Properties. On the Back-end Storage tab in properties notebook, click Edit.
Back-End Storage System Type
The type of storage system that is providing storage space to a pool. Available only for pools on storage systems that run IBM Storage Virtualize.
If the back-end storage system was not probed, then the value in this column is blank. To manually select a type of storage system to help calculate the approximate read I/O capability of the pool, right-click a pool in the list and select View Properties. On the Back-end Storage tab in properties notebook, click Edit.
Capacity Limit (%) and Capacity Limit (GiB)

The limit that was set on the capacity that is used by your pools. For example, the policy of your company is to keep 20% of the usable capacity of your pools in reserve. So, you log into the GUI as Administrator and set the capacity limit of your pools to 80%.

Set the capacity limit Set the capacity limit

Tip Click the illustration above to find out how to set capacity limits.

The GiB value for the capacity limit for the pool is calculated when you set the value for the Capacity Limit (%).

To add the Capacity Limit (%) and the Capacity Limit (GiB) columns, right-click any column heading on the Pools page.

See these related values for more information Adjusted Used Capacity (%) and Capacity-to-Limit (GiB).

Zero capacity: When you set the capacity limit for pools, the values shown for Zero Capacity are readjusted to take into account the capacity limit of the pool. The date will represent when the capacity limit of the pool is reached. If the pool has already reached the capacity limit, Depleted is shown. None is shown when a trend in storage consumption can't be detected because the pool's storage isn't being consumed or because not enough data was collected to predict storage consumption.
Availability: This metric is not available for all storage systems, such as Dell EMC VMAX.
Capacity-to-Limit (GiB)

The amount of capacity that is available before the capacity limit is reached.

Capacity-to-limit

The formula for calculating Capacity-to-Limit (GiB) is (Capacity Limit in GiB - Used Capacity in GiB). For example, if the capacity limit is 80% or 80 GiB and the used capacity is 40 GiB, then the value for Capacity-to-Limit (GiB) is (80 GiB - 40 GiB or 80% - 50%) which is 30% or 40 GiB.

See these related values for more information Capacity Limit (%) and Adjusted Used Capacity (%).

This metric is not available for all storage systems, such as IBM FlashSystem A9000, IBM FlashSystem A9000R, and Dell EMC VMAX.

Compressed Capacity
Total used capacity for all compressed volume copies in regular storage pools.
Compression Opportunity
The total capacity of all compressed volume copies in a data reduction pool.
Custom tag 1, 2, and 3
Any user-defined text that is associated with the pool. This text can be included in reports that you create for the pool.
Data Reduction Status
The physical capacity status. This column is shown for DS8000 storage systems only.
Data Reduction Threshold (% full)
The maximum threshold percentage of the used physical capacity. This column is shown for DS8000 storage systems only.
Deduplication Capacity Savings
Indicates the total amount of used capacity that is saved by data deduplication. This saving is before any compression.
Deduplication Savings (%)
The estimated amount and percentage of capacity that is saved by using data deduplication. The percentage is calculated across all deduplicated volumes in the pool and does not include the capacity of volumes that are not deduplicated.
The following formula is used to calculate the amount of storage space that is saved: 
written capacity − deduplicated size
The following formula is used to calculate the percentage of capacity that is saved:
((written capacity − deduplicated size) ÷ written capacity) × 100
For example, the written capacity, which is the amount of data that is written to the volumes before deduplication, is 40 GiB. The deduplicated size, which reflects the size of deduplicated data that is written to disk, is just 10 GB. Therefore, data deduplication reduced the size of the data that is written by 75%.
Availability: Storage systems that run IBM Storage Virtualize 8.1.3 or later.
Easy Tier
The Easy Tier value determines whether Easy Tier is enabled and the Easy Tier Status determines how tiering is managed. For example, Easy Tier can be configured to tier all pools, single-tier pools (pools with one class drive), or multitier pools (pools with multiple class drives).
You can configure Easy Tier for DS8000 and storage systems that run IBM Storage Virtualize.

The following table shows the possible Easy Tier and related Easy Tier Status values:

Number of Tiers Easy Tier Easy Tier Status
One Off Inactive
Two or more Off Inactive
One Measure Measured
Two or more Measure Measured
One Auto Balanced
Two or more Auto Active
One On Balanced
Two or More On Active
Encryption Group
The identifier of the encryption group that was specified when the pool was created. Available only for DS8000 pools.
Enterprise HDD Available Capacity (GiB)
The amount of storage space that is available on the Enterprise hard disk drives that can be used by Easy Tier for re-tiering the volume extents in the pool.
Availability: DS8000 and storage systems that run IBM Storage Virtualize.
Enterprise HDD Capacity (GiB)
The total amount of storage space on the Enterprise hard disk drives that can be used by Easy Tier for re-tiering the volume extents in the pool.
Availability: DS8000 and storage systems that run IBM Storage Virtualize.
Extent Size (MiB)
The extent granularity that was specified when a pool was created. Smaller extent sizes limit the maximum size of the volumes that can be created in a pool, but minimize the amount of potentially wasted space per volume. Available for pools on DS8000 and storage systems that run IBM Storage Virtualize only.
Format
The formats of the volumes that are allocated from a pool, such as FB (fixed block) or CKD (count key data). Available only for DS8000 pools.
Flash Core Module Capacity (GiB)
The total usable capacity in gibibytes (GiB) of all FlashCore Modules (FCMs) that are part of the storage pool. This column is shown for DS8000 storage systems only.
Flash Core Module Available Capacity
The storage pool’s total usable capacity that is provided by FlashCore Modules. This column is shown for DS8000 storage systems only.
Free Extents
Number of free extents in pool.
Mapped Capacity (GiB)
The space on all of the volumes in a pool that are mapped or assigned to host systems. For a thin-provisioning pool, this value includes the provisioned capacity of thin-provisioned volumes, which might exceed the total space in the pool.
Nearline HDD Available Capacity (GiB)
The amount of storage space that is available on the Nearline hard disk drives that can be used by Easy Tier for re-tiering the volume extents in the pool.
Availability: DS8000 and storage systems that run IBM Storage Virtualize.
Nearline HDD Capacity (GiB)
The total amount of storage space on the Nearline hard disk drives that can be used by Easy Tier for re-tiering the volume extents in the pool.
Availability: DS8000 and storage systems that run IBM Storage Virtualize.
Number of Extents
Number of extents in pool.
Overhead Capacity (GiB)
The amount of usable capacity that is occupied by metadata in a pool or system and other data that is used for system operation.
Overprovisioned Capacity (GiB)
(Previously known as Unallocatable Volume Space) The capacity that cannot be used by volumes because the physical capacity of the pool cannot meet the demands for provisioned capacity. The following formula is used to calculate this value:
[Provisioned Capacity − Capacity]
In thin-provisioned environments, it is possible to over commit (over provision) storage in a pool by creating volumes with more provisioned capacity than can be physically allocated in the pool. This value represents the amount of volume capacity that cannot be allocated based on the current capacity of the pool. For Hitachi VSP non-thin provisioned pool capacity, this value is always zero.
Availability: All storage systems, except IBM FlashSystem A9000, IBM FlashSystem A9000R, XIV, and IBM Storage Accelerate.
Over Provisioning Ratio
The total provisioned capacity divided by total real capacity that is allowable for the volume. This column is shown for DS8000 storage systems only.
Over Provisioning Ratio Limit
Indicates if the overprovisioning is allowed on the extent pool. This column is shown for DS8000 storage systems only.
Owner Name
The name of the user who owns the child pool.
Parent Name
The name of the parent pool.
Pool Attributes

Shows whether data reduction, encryption, thin provisioned, or all the three are configured for the pool. If neither feature is configured, the column is blank.

Data reduction is available for pools on IBM FlashSystem A9000, IBM FlashSystem A9000R, and storage systems that run IBM Storage Virtualize 8.1.1 or later.

Encryption is available for all pools.
Examples:
  • If only data reduction is configured, the value Data Reduction is shown.
  • If only encryption is configured, the value Encryption is shown.
  • If both features are configured, the value Data Reduction, Encryption is shown.
Pool Compression Ratio
The ratio of the uncompressed data size to the compressed data size for a particular pool in a storage system.
Availability: Storage systems that run IBM Storage Virtualize 8.4.0.0 or later.
Pool Compression Savings
The estimated amount and percentage of capacity that is saved in a particular pool of a particular storage system.
Availability: Storage systems that run IBM Storage Virtualize 8.4.0.0 or later.
Pool threshold (% full)
The maximum threshold percentage of the used real extents. This column is shown for DS8000 storage systems only.
RAID Level
The RAID level of the pool, such as RAID 5 and RAID 10. The RAID level affects the performance and fault tolerance of the volumes that are allocated from the pool. In some cases, there might be a mix of RAID levels in a pool. The RAID levels in a mixed pool are shown in a comma-separated list.
Rank Group
The rank group to which a pool is assigned. Available only for DS8000 pools.
Recent Fill Rate (%)

The rate at which the capacity of the pool is being consumed over the last 30 days. Use this value to see how quickly your pools are filling up.

Fill rate for pools
If 30 days of historical data is not available, it is the difference between today's fill rate % and the oldest value for the fill rate % in the last 30 days.

If you want to add the growth in used capacity in GiB, right-click any column heading and click Recent Growth (GiB).

This metric is not available for all storage systems, such as IBM FlashSystem A9000, IBM FlashSystem A9000R, and Dell EMC VMAX.

Recent Growth (GiB)

The amount of used capacity that is consumed by the storage system over the last 30 days. Use this value to identify the pools with the highest growth rates in used capacity.

Recent growth is the difference between today's used capacity of the pool and the used capacity of the pool that was reported 30 days ago. If 30 days of historical data is not available, it is the difference between today's used capacity for the pool and the oldest value for the used capacity of the pool that was reported in the last 30 days.

Availability: This metric is not available for all storage systems, such as IBM FlashSystem A9000, IBM FlashSystem A9000R, and Dell EMC VMAX.
Reclaimable Capacity
Unused capacity that will be available after data is reduced.
Repository Capacity (GiB)
The total storage capacity of the repository for Track Space-Efficient (TSE) thin-provisioning.
Availability: DS8000 thin-provisioned pools.
Reserved Volume Capacity
(Previously known as Unused Space) The amount of pool capacity that is reserved but has not been used yet to store data on the thin-provisioned volume.
Availability: Resources that run IBM Storage Virtualize.
Safeguarded Capacity (GiB)

The capacity that is consumed by all of the Safeguarded Copies for a source volume in IBM Storage Virtualize and DS8000. This value applies only to volumes that are the source in a Safeguarded Copy relationship.

SCM Available Capacity (GiB)
The available capacity on Storage Class Memory (SCM) drives in the pool. Easy Tier can use these drives to retier the volume extents in the pool.
Availability: IBM Storage Virtualize systems, such as IBM Storage FlashSystem 9100, IBM Storage FlashSystem 7200, and Storwize family storage systems that are configured with block storage.
SCM Capacity (GiB)
The total capacity on Storage Class Memory (SCM) drives in the pool. Easy Tier can use these drives to retier the volume extents in the pool.
Availability: IBM Storage Virtualize systems, such as IBM Storage FlashSystem 9100, IBM Storage FlashSystem 7200, and Storwize family storage systems that are configured with block storage.
Shortfall (%)
The difference between the remaining unused volume capacity and the available capacity of the associated pool, expressed as a percentage of the remaining unused volume capacity. The shortfall represents the relative risk of running out of space for overallocated thin-provisioned volumes. If the pool has sufficient available capacity to satisfy the remaining unused volume capacity, no shortfall exists. As the remaining unused volume capacity grows, or as the available pool capacity decreases, the shortfall increases and the risk of running out of space becomes higher. If the available capacity of the pool is exhausted, the shortfall is 100% and any volumes that are not yet fully allocated have run out of space.
If the pool isn't thin-provisioned, the shortfall percentage equals zero. If shortfall percentage isn't calculated for the storage system, the field is left blank.
The following formula is used to calculate this value: 
Overprovisioned Capacity ÷ Committed but Unused Capacity
You can use this percentage to determine when the amount of over-committed space in a pool is at a critically high level. Specifically, if the physical space in a pool is less than the committed provisioned capacity, then the pool does not have enough space to fulfill the commitment to provisioned capacity. This value represents the percentage of the committed provisioned capacity that is not available in a pool. As more space is used over time by volumes while the pool capacity remains the same, this percentage increases.
Example: The remaining physical capacity of a pool is 70 GiB, but 150 GiB of provisioned capacity was committed to thin-provisioned volumes. If the volumes are using 50 GiB, then 100 GiB is still committed to the volumes (150 GiB − 50 GiB) with a shortfall of 30 GiB (70 GiB remaining pool space − 100 GiB remaining commitment of volume space to the volumes).
Because the volumes are overcommitted by 30 GiB based on the available capacity in the pool, the shortfall is 30% when the following calculation is used: 
[(100 GiB unused volume capacity − 70 GiB remaining pool capacity)
 ÷ 100 GiB unused volume capacity] × 100
Availability: DS8000, Hitachi Virtual Storage Platform, and storage systems that run IBM Storage Virtualize.

For IBM FlashSystem A9000 and IBM FlashSystem A9000R, this value is not available.

Soft Capacity (GiB)
The amount of virtual storage space that is configured for the pool.
Availability: XIV systems and IBM Storage Accelerate storage systems.
Solid State
Shows whether a pool contains solid-state disk drives. If a pool contains solid-state disks and other disks, the value Mixed is shown.
Status
The status of a pool. Statuses include Normal, Warning, Error, and Unknown. Use the status to determine the condition of a pool, and if any actions must be taken. For example, if a pool has an Error status, take immediate action to correct the problem.
Tier
The tier level of pools on storage virtualizers. If the pool is not assigned a tier level, the cell is blank. To set or change the tier level, select one or more pools. Right-click, and then select Set Tier. Note that tier changes to a parent or child pool affect all pool family members.
Tier 0 Flash Available Capacity (GiB)
The amount of storage space that is available on the Tier 0 flash solid-state drives that can be used by Easy Tier for retiering the volume extents in the pool.
Availability: DS8000 and storage systems that run IBM Storage Virtualize.
Tier 0 Flash Capacity (GiB)
The total amount of storage space on the Tier 0 flash solid-state drives that can be used by Easy Tier for retiering the volume extents in the pool.
Availability: DS8000 and storage systems that run IBM Storage Virtualize.
Tier 1 Flash Available Capacity (GiB)
The amount of storage space that is available on the Tier 1 flash, read-intensive solid-state drives that can be used by Easy Tier for retiering the volume extents in the pool.
Availability: DS8000 and storage systems that run IBM Storage Virtualize.
Tier 1 Flash Capacity (GiB)
The total amount of storage space on the Tier 1 flash, read-intensive solid-state drives that can be used by Easy Tier for retiering the volume extents in the pool.
Availability: DS8000 and storage systems that run IBM Storage Virtualize.
Tier 2 Flash Available Capacity (GiB)
The available capacity on Tier 2 flash, high-capacity drives in the pool. Easy Tier can use these drives to retier the volume extents in the pool.
Availability: DS8000 storage systems.
Tier 2 Flash Capacity (GiB)
The total capacity on Tier 2 flash, high-capacity drives in the pool. Easy Tier can use these drives to retier the volume extents in the pool.
Availability: DS8000 storage systems.
Tier Distribution (%)
The distribution of volume extents across the Easy Tier drive classes in a pool, such as the percentage of volume extents on SCM drives, Tier 0, Tier 1, and Tier 2 flash drives, Enterprise hard disk drives, and Nearline hard disk drives.
Total Savings (%)
The estimated amount and percentage of capacity that is saved by using data deduplication, pool compression, thin provisioning, and drive compression, across all volumes in the pool.
The following formula is used to calculate the amount of storage space that is saved: 
Total Provisioned − Used Capacity
The following formula is used to calculate the percentage of capacity that is saved: 
((Total Provisioned − Used Capacity) ÷ Total Provisioned) × 100
Availability: IBM FlashSystem A9000 and IBM FlashSystem A9000R, IBM Storage Accelerate, XIV storage systems with firmware version 11.6 or later, and resources that run IBM Storage Virtualize.
Total Compression Ratio
The ratio of the uncompressed data size to the compressed data size for all the pools in a storage system.
Availability: DS8000 and storage systems that run IBM Storage Virtualize 8.4.0.0 or later.
Total Compression Savings
The estimated amount and percentage of capacity that is saved in all pools in a particular storage system by using data compression techniques.
Availability: Storage systems that run IBM Storage Virtualize 8.4.0.0 or later.
Total Provisioned (GiB)
The total amount of provisioned capacity of volumes within the pool. If the pool is a parent pool, it also includes the storage capacity that can be made available to the volumes in the child pools.
Availability: All storage systems.
Total Provisioned (%)
(Previously known as Provisioned capacity) The percentage of the physical capacity that is committed to the total provisioned capacity of the volumes in the pool. If the value is greater than 100%, more provisioned capacity is committed to the volumes than is physically available to the pools. The following formula is used to calculate this value:
[(Total Provisioned ÷ Capacity) × 100]

For example, if the total provisioned percentage is 200% for a storage pool with a physical capacity of 15 GiB, then the total provisioned that is committed to the volumes in the pools is 30 GiB. Twice as much capacity is committed to the pools than is physically available to the pools. If the total provisioned percentage is 100% and the physical capacity is 15 GiB, then the total provisioned that is committed to the pools is 15 GiB. The total physical capacity that is available to the pools is allocated to the volumes in the pools.

A total provisioned percentage that is higher than 100% is considered aggressive because insufficient physical capacity is available in the pool to satisfy the maximum allocation for all the thin-provisioned volumes in the pool.  In such cases, you can use the value for Shortfall (%) to estimate how critical the shortage of space is for a pool.
Availability: All storage systems.
Uncompressed Capacity
Total uncompressed used capacity for all compressed volume copies in regular storage pools.
Unmapped Capacity (GiB)
The total amount of space in the volumes that are not assigned to hosts. For a thin-provisioning pool, this value includes the provisioned capacity of thin-provisioned volumes, which might exceed the total space in the pool.
Usable Capacity (GiB)
The total amount of storage space in the pool. For XIV systems and IBM Storage Accelerate, capacity represents the physical or ("hard") capacity of the pool, not the provisioned ("soft") capacity.
Availability: All storage systems.
Used Capacity (%)

(Previously known as Physical Allocation)

Illustration of used capacity percentage
The percentage of physical capacity that is used by the volumes in the pool, including the volumes in child pools. This value is always less than or equal to 100% because you cannot allocate more physical space than is available in a pool. Check the value for used capacity to see:
  • Whether the physical capacity of the pool is fully allocated. That is, the value for used capacity is 100%.
  • Whether you have sufficient capacity to provision new volumes with storage
  • Whether you have sufficient capacity to allocate to the compressed and thin-provisioned volumes in the pool
Availability: All storage systems, except IBM FlashSystem A9000 and IBM FlashSystem A9000R.
Used Capacity (GiB)
(Previously known as Allocated Space) The amount of physical capacity that is used by the volumes in the pool. If the pool is a parent pool, the amount of space that is used by the volumes in the child pools is also included.
The capacity that is used by thin-provisioned volumes is less than their provisioned capacity, which is shown in the Provisioned Capacity column. If a pool does not contain thin-provisioned volumes, this value is the same as Provisioned Capacity .
Availability: All storage systems, except IBM FlashSystem A9000 and IBM FlashSystem A9000R.
Used Capacity After Reduction
Total amount of data that is written to thin-provisioned and compressed volume copies that are in data reduction storage pools - after data reduction occurs.
Used Capacity Before Reduction
Total amount of data that is written to thin-provisioned and compressed volume copies that are in data reduction storage pools - before data reduction occurs.
Used Written Capacity (GiB)
(Previously known as Effective Used Capacity) The amount of capacity that is written to the volumes in a pool before inline disk compression is applied. If a pool is not compressed, this value is the same as Used Capacity.
Volumes
The number of volumes that are allocated from a pool.
Written Capacity Limit (GiB)
(Previously known as Effective Capacity) The maximum of amount of capacity that can be written to a pool before inline-disk compression is applied. If a pool is not compressed, this value is the same as Capacity.
Zero Capacity
The capacity information that is collected over 180 days is analyzed to determine, based on historical storage consumption, when the pools will run out of capacity. The pools that have already run out of capacity are marked as depleted. For the other pools, a date is provided so that you know when the pools are projected to run out of capacity. None is shown when a trend in storage consumption can't be detected because the pool's storage isn't being consumed or because not enough data was collected to predict storage consumption. When you set the capacity limit for pools, the values shown for Zero Capacity are readjusted to take into account the capacity limit of the pool. The date will represent when the capacity limit of the pool is reached. If the pool has already reached the capacity limit, depleted is shown.
For a demonstration of the Zero Capacity value, watch the video at https://youtu.be/hIhpG_TymS8.