# Pools
## Understanding Storage Pools
Storage Pools are virtual entities that manage storage provisioning from
the aggregated capacity of one or more RAID Groups pooled into a single
construct with some QoS attributes.
Volumes are thinly provisioned, allocating capacity from the Pool only
when needed. The Pool has an underlying block virtualization layer which
maps virtual address space to physically allocated Pool space and
manages sharing of Pool physical chunks between Volumes, Snapshots and
Clones.
Snapshots and Clones consume zero capacity when they are created
because they share the same data chunks as the originating Volume. Anytime
you actually modify the data in the Volume, or in one of the Clones, the
data chunk is copied-on-write (COW) from the source in order to apply the
new data write to a new Pool region without affecting the data set of any
other objects that share the same data chunk.
The Pool’s attributes define the way Volumes, Snapshots and Clones are
provisioned.
A single VPSA can have multiple storage pools based on the VPSA type and
engine type according to the following specifications:
* **VPSA Storage Array** - 3 Pools
* **VPSA Flash Array**
* H100 - 1 Pool
* H200 - 2 Pools
* H300 - 2 Pools
* H400 - 2 Pools
### Tiers
Scope: VPSA Flash Array
Supported configurations:
- Tier 0 is SSD and Tier 1 (low tier) is HDD.
- Tier 0 is SSD and Tier 1 (low tier) is Remote Object Storage.
Inline data reduction is supported irrespective of the actual data location.
Data storage placement in the VPSA Pool is aligned dynamically, based on an
internal heat index.
Scanning, promotion and demotion of the storage location between tiers is
embedded in the VPSA garbage collection cycle.
The VPSA tier manager keeps track of heat scores for the hottest LSA chunks
in each tiered Pool.
The heat score is calculated according to:
- Frequency of chunk read-write operations
- Chunk deduplication references
The VPSA attempts to stabilize SSD utilization at a steady state around 80%.
| SSD utilization | Promotion and demotion considerations |
|-------------------------------------------------|----------------------------------------------------------|
| Below steady state | All data is retained in SSD and no demotions take place. |
| At stabilization target
around steady state | Placement considerations, promotions and demotions. |
| Above steady state | Demotions are increased and promotions are blocked. |
**Chunk promotion**: Chunks can be promoted to a higher tier:
- By the low tier defragger
- On host reads
- By the tier manager, based on periodic assessing of chunks with highest heat scores
**Chunk tier demotion**: Chunks can be demoted to a lower tier:
- By the SSD defragger
- By the tier manager, when SSD utilization is at the steady state and higher
## Understanding Pool’s Capacity
Scope: VPSA Flash Array
The introduction of data reduction makes the Pool capacity management more complex.
Data reduction efficiency depends on the nature of the data, therefore it is harder
to predict the drive capacity needed for each workload.
Capacity metrics to consider:
### Physical View
**Raw Capacity** - Sum of all drives capacities in the Pool
**Usable Capacity** - Total capacity of all RAID Groups in the Pool
**Used by Volumes** - Capacity used to store the Volumes’ data
**Used by metadata** - Capacity used to store the Pool’s metadata
**Used by data copies:** - Capacity used to store the Snapshots and Clones
**Used Capacity** - The total size of all data written in the Pool
*Used Capacity = Used by Volumes + Used by metadata + Used by data copies*
**Free Capacity** - Available Capacity in the Pool that can be used for new Data and Metadata writes
*Free Capacity = Usable Capacity – Used Capacity*
*%Full = “Used Capacity” / “Usable Capacity”*
### Virtual View
**Provisioned Capacity** - Sum of Pool’s Volumes and Clones capacities as seen by the hosts
**Allocated Capacity** - Pool’s allocated address space of all Volumes, Snapshots and Clones
**Allocation Limit** - Max Capacity of the Pool’s address space. Depends on the Pool type.
*Free Address Space = Allocation Limit – Allocated Capacity*
**Effective Capacity** - Amount of data written in the Pool by all Volumes and can be accessed by hosts.
Not including space taken by Snapshots
### Data Reduction Saving
**Thin Provision Ratio** = Provisioned Capacity / Effective Capacity
**Data Reduction Ratio** = Effective Capacity / Used by Volumes
**Data Reduction Saving** = Effective Capacity - Used by Volumes
**Data Reduction Percentage** = 1- (1 / Data Reduction Ratio)
e.g.
Data reduction ratio 2:1 , Data Reduction Percentage 50%
Data reduction ratio 5:1 , Data Reduction Percentage 80%
Data reduction ratio 20:1 , Data Reduction Percentage 95%
### Pool Capacity Monitoring
The VPSA Flash Array **Dashboard** shows the capacity
consumption and data reduction saving.
The upper bar shows the current capacity provisioned to the hosts by all Pools vs.
the effective
capacity written by the hosts vs. the physical space needed to store the data.
The lower chart shows trend of time of the physical capacity used and available.
The Pools table on the **Pools** page shows 2 bars per Pool:
- The **Physical capacity** bar shows the usable vs. used capacities.
- The **Virtual capacity** bar shows the allocated capacity vs. the allocation limit.
## Viewing the List of Pools
The Pools page displays a table listing the VPSA’s Pools in the upper part
of the screen.
Both VPSA Storage Array Pools and VPSA Flash Array Pools have the following
common columns:
| **Property** | **Description** |
|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Name | User assigned name. Can be modified anytime. |
| Status | - Normal
- Creating
- Deleting
- Partial/Failed – At least one of the underlying RAID Groups has failed, or the Pool metadata cannot be initialized at Start Of the Day. |
| Raid Group(s) | RAID Group name, or “Multiple (X)” where X denotes the number of RAID Groups in the Pool. |
* Columns specific to VPSA Storage Array Pools:
| **Property** | **Description** |
|----------------------|---------------------------------------------------------------------------|
| Capacity | Total available capacity for user data and system metadata. |
| Type | - Transactional Workloads
- Repository Storage
- Archival Storage |
| Cached | Yes/No – Indicates whether the Pool utilizes SSD for read/write caching. |
| Provisioned Capacity | Sum of Pool’s Volumes and Clones capacities as seen by the hosts. |
* Columns specific to VPSA Flash Array Pools:
| **Property** | **Description** |
|----------------------|------------------------------------------------------------------------------------------------------------------|
| Physical Capacity | The usable vs. used capacities in the Pool. |
| Virtual Capacity | The allocated capacity vs. the allocation limit in the Pool. |
| Type | - IOPS-Optimized
- Balanced
- Throughput-Optimized |
| Data Reduction Ratio | Capacity savings by all data reduction techniques. *Data Reduction Ratio = Effective Capacity / Used by Volumes* |
### Filtering the List of Pools
To filter the list of Pools displayed in the center pane, you can use
a predefined custom tag.
1. Expand the **Filter** control.
2. On the right, click the **Add Filter** dropdown, and select **Tag**.
The tag input fields appear on the left.
3. The **Tag** filter requires input of the predefined custom **Tag Name**,
and optionally, a **Tag Value** to further refine filtering for tags
that have specific values for assigned Pools.
Wildcards are not accepted.
See the [Tags tab](#pool-tags-tab) section for configuring predefined
custom tags.
4. Click **Search** to apply the filter.
5. To remove the filter, click **Clear**, or click the trash icon to the
right of the filter.
Click **Search** again to refresh the Volumes list.
## Creating and Managing Pools
### Creating a Pool
To create a new Storage Pool press either the Create button on
the Pools page or the Create Pool button on the RAID Groups page.
There are 2 methonds to create a Pool:
* Create a Pool from RAID Groups
* Create a Pool from drives, and the let the system automatically create the needed RAID Groups.
You can toggle between the two by clicking Use Drive Selection / Use RAID Group Selection
at the lower left corner of the dialog
#### Create a Pool from RAID Groups
To create a Pool from RAID Groups, click the **Create** button on the Pools
page.
The **Create Pool** dialog opens. At the lower left, select
**Use RAID Group Selection** from the toggle:
Select the Pool attributes:
- **Display Name** – You can modify this anytime later.
- **RAID Group(s) selection** – Check the box(es) of one or more RAID
Groups from which protected storage capacity will be allocated for
this Pool.
- **Capacity** – The Pool’s physical capacity shown in GB. By default
the capacity is the aggregated capacities of all the selected RAID
Groups, but you do not have to allocate full RAID Groups. If you
define a capacity smaller than is available in the selected RAID
Groups the capacity will be evenly distributed between the RAID
Groups.
- **Type**
- VPSA Storage Array supports Transactional, Repository, Archive Pool
and Depot Pool types.
- VPSA Flash Array supports IOPS-Optimized, Balanced Pool and
Throughput-Optimized Pool types.
These Pool types use different chunk sizes for the mapping of
virtual LBAs to Physical Drive addresses.
The following tables
describe the tradeoffs for each type and the recommended use cases:
VPSA Storage Array **Pool types**:
| | **Transactional Pool** | **Repository Pool** | **Archive Pool** | **Depot Pool** |
|------------------|-----------------------------------------------------------------------------|-------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| **Chunk size** | 256KB | 1MB | 2MB | 4MB |
| **Pros** | - Faster COW operation
- Space efficiency on random writes to Snapshots | - Smaller metadata size
- Sequential workload performance is similar to transactional | - Allows large Pools
- Sequential workload performance is the same | - Optimal capacity consolidation for backup and media storage |
| **Cons** | - Increased metadata size | - Slower COW operation
- Less space efficient | - Slower with frequent data modifications
- Limited Snapshots frequency (1 hour min) | - Slower for small block transactional workloads (optimal support for workloads with IO block size >=256KB)
- Limited Snapshot frequency (1 per day with 30 days retention)
- Less space-efficient for small files (recommended for file sizes >= 1MB) |
| **Use case** | - Transactional workload with Snapshots | - Repository type workload
- Large Pools
- Many Snapshots to keep | - Relatively static data
- Archive type workloads
- Very large Pools/Volume (> 100TB) | - Backup repositories
- Media repositories
- Large files archive |
| **Maximum size** | 20TiB | 100TiB | 200TiB | 500TiB |
VPSA Flash Array **Pool types**:
| | **IOPS-Optimized Pool** | **Balanced Pool** | **Throughput-Optimized Pool** |
|-------------------------------|----------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| **Thin Provision Chunk size** | 1MB | 2MB | 4MB |
| **Deduplication Chunk size** | 16KB | 32KB | 64KB |
| **Pros** | - Smaller metadata size
- Better deduplication
- Lower COW overhead in cases of small block I/O | - Allows large Pools
- Better sequential workload throughput compared
to IOPS-Optimized Pools
- Better compression ratio compared
to IOPS-Optimized Pools | - Optimal capacity consolidation for backup and
media storage
- Better sequential workload throughput compared
to other Pool types
- Better compression ratio compared to other Pool
types |
| **Cons** | - Increased metadata size | - Higher COW overhead for IOPS < 16KB in
comparison to IOPS-Optimized Pools
- Lower deduplication efficiency compared to
IOPS-Optimized Pools | - Higher COW overhead for IOPS < 32KB in
comparison to other Pool types
- Higher latency for small block writes < 64KB due
to RMW
- Less space-efficient for small files
(recommended for file sizes >= 1MB)
- Low deduplication efficiency (recommendation is
to turn deduplication off) |
| **Use Case** | - Analytics
- Small block IOPS workloads
- High IOPS
- Database (OLTP)
- Deduplication-friendly data | - Pools/Volumes (> 100TB)
- Archive type workloads
- Workloads with average IO block size of 32KB
- General purpose
- File system | - Relatively static data
- Backup repositories
- Media repositories
- Large file archives
- Archive type workloads
- Sequential workloads auch as video streaming
- Workloads with average IO block size > 128KB |
| **Maximum size** | 100TiB | 200TiB | 500TiB |
When there are a number of Pools in a given VPSA, there is a limit to the
aggregated total size of all Pools.
The following table lists the maximimum capacity per Pool type in TB,
per VPSA Flash Array engine:
| | | | | |
|----------------------|------|------|------|------|
| | H100 | H200 | H300 | H400 |
| IOPS-Optimized | 60 | 100 | 100 | 100 |
| Balanced | 100 | 160 | 200 | 200 |
| Throughput-Optimized | 140 | 220 | 400 | 500 |
- **Cached** – Check this box to use SSD to Cache Server’s reads and
writes.
- All Pools that are marked as “Cached” share the VPSA Cache.
- Flash cache usually improves the performance of Volumes based on HDD’s Pools.
However it depends on the specific workload and the size of the cache
vs. the size of the active data set.
- If the Pool consists of SSD drives this option will be disabled.
- **Striped** – This check box is enabled only when you select two or
more RAID Groups. Striping over RAID-1 creates a
RAID-10 configuration. Use striping to
improve performance of random workloads, since the IOs will be
distributed and all drives will share the workload.
VPSA Flash Array Pools are always striped, and the
**Striped** check box is hidden.
#### VPSA Flash Array configurations
Scope: VPSA Flash Array
- **Additional Storage Class**: Adding a storage class defines a low tier
for the Pool as HDD or remote Object Storage. Adding a storage class opens
the **SSD Cool Off** configuration option.
- **SSD Cool Off**: Set a goal for data retention in SSD with a value of
0 to 720 hours (30 days). The default is 0 (disabled). This hints to
the system that within the cool-off period there will be a repeated
access to a data chunk in the Pool. When SDD utilization is around
the steady state, the tiering manager references the cool-off period
definition in its decision to determine tier placement for the data chunk.
#### Create a Pool from Drives
To create a Pool from Drives, click the **Create** button on the Pools page.
The **Create Pool** dialog opens. At the lower left, select
**Use Drive Selection** from the toggle:
The parameters are the same as above. Check the boxes of drives that will be allocated for
this Pool.
### Expanding Pool Capacity
To Expand the Pool press the Expand button on the Pools page.
You can use capacity from any RAID Group to expand a Pool.
#### VPSA Flash Array configuration
Scope: VPSA Flash Array
**Expand in Storage Class**: Choose SSD or HDD to list the storage class
resource details and availability for expansion.
### Shrinking Pool Capacity
Scope: VPSA Flash Array
If the Pool capacity is not fully used you can shrink it’s size by removing
one RAID Group at a time from the Pool. The VPSA will evacuate the selected RAID Group and will return
the RAID Group to the VPSA for reuse, or for the RAID Group to be deleted and the drives removed from the VPSA.
To Shrink the Pool press the Shrink button on the Pools page.
**Storage Class to Shrink**: Choose SSD or HDD to list the storage class
RAID Group details and availability for shrinkage.
Select the RAID Group to remove from the Pool. Check the physical size expected after the
shrinking operation is completed, and press Shrink.
The operation might take a while, depending on the amount of data to be copied to other drives.
The system will generate an Event once done.
### Caching
Scope: VPSA Storage Array
It is possible to enable Caching on non-cached Pools.
One use case for leveraging this capability is to enable caching only
after the initial copy of the data into the VPSA. The initial copy
typically generates a sequential write IO workload, where non-cached
Pools are most efficient. Once the initial copy is completed enable
caching on the Pool if you expect a more random type of IO workload.
### Disabling SSD cache on a Pool
Scope: VPSA Storage Array
By default every Pool is cached by the VPSA’s SSD cache, but it is also
possible to disable caching on cached Pools which will remove this
feature. The Enable Cache/Disable Cache buttons toggle depending on the
current caching state of the Pool.
### Creating a Volume
A Volume can be created from the **Create Volume** button in the top menu in
the Pools view or in the Volumes view. Both flows are identical.
See [Creating and Deleting a Volume](volumes.md#creating-and-deleting-a-volume) on the
**Managing Volumes, Snapshots and Clones** page.
### Creating a share
A NAS share can be created from the **Create Share** button in the top menu in
the Pools view or in the Volumes view. Both flows are identical.
See [Creating a NAS share](volumes.md#creating-nas-share) on the
**Managing Volumes, Snapshots and Clones** page.
### Adding a tier
Scope: VPSA Flash Array
It is possible to add a low tier to an existing VPSA Flash Array Pool.
1. In the **Pools** view, search for the Pool in the Pool table, and
mark it by clicking its row.
2. Click **Create** in the top menu.
The **Create Pool** dialog opens.
1. Select the high tier from the list in the **SSD Storage Class**
table.
2. Select the **Additional Storage Class**: Either **HDD** or **OBS**
(remote Object Storage).
Depending on the selection, either the **HDD Storage Class** list
or the **OBS Storage Class** list is displayed.
The **SSD Cool Off** field is also displayed.
3. Select the low tier from the **HDD Storage Class** or
**OBS Storage Class** list.
4. Set the number of hours for **SSD Cool Off**, between 0 and 720
(30 days).
During the cool-off period there is repeated access to data chunks
in the Pool.
The tiering manager references the cool-off period definition
to determine tier placement for data chunks.
5. Click **Create**.
The tier’s properties will be viewable in the [Tiers tab](#pool-tiers-tab).
## Viewing Pool properties
The Pool’s details are shown in the following South Panel tabs:
### Properties tab
#### VPSA Storage Array Pool properties
Scope: Scope: VPSA Storage Array
Each VPSA Storage Array Pool has the following properties:
| **Property** | **Description** |
|--------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ID | An internally assigned unique ID. |
| Name | User assigned name. Can be modified anytime. |
| Status | - Normal
- Creating
- Deleting
- Partial/Failed – At least one of the underlying RAID Groups has failed, or the Pool metadata cannot be initialized at Start Of the Day. |
| Comment | User free text comment. Can be used for labels, reminders or any other purpose. |
| Type | - Transactional Workloads
- Repository Storage
- Archival Storage |
| Mode | - Simple – There are one or more concatenated RAID Groups.
- Stripe – There are two or more striped RAID Groups.
- Mixed – There are two or more concatenated *and* striped RAID Groups. |
| Cached | Yes/No – Indicates whether the Pool utilizes SSD for read/write caching. |
| Cache COW Writes | Yes/No – Indicates whether flash cache is used for internal Snapshots Copy-On-Write Operations. Enabled by default. Disabled only on rare cases where frequent Snapshots cause extreme load of metadata operations. Consult Zadara support. |
| Raid Group(s) | RAID Group name, or “Multiple (X)” where X denotes the number of RAID Groups in the Pool. |
| Stripe Size | Applicable only for Pools of Striped mode (i.e. when data is striped between 2 or more RAID Groups). The Stripe size is always 64KB. |
| Created | Date & time when the object was created. |
| Modified | Date & time when the object was last modified. |
| Capacity | Total available capacity for user data & system metadata. |
| Available Capacity | Available (free) capacity to be used for User data. VPSA reserves 2% of the total Pool capacity for system metadata. If the VPSA needs more capacity for the metadata (very rare scenario), it will be consumed from the available capacity. |
| Metadata Capacity | Capacity used by the metadata that is required for managing pool allocation space. |
| Capacity State | - Normal
- Alert
- Protected
- Emergency
See [Managing Pool Capacity Alerts](#managing-pool-capacity-alerts) for more details. |
#### VPSA Flash Array Pool properties
Scope: VPSA Flash Array
Each VPSA Flash Array Pool has the following properties:
| **Property** | **Description** |
|----------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| | **General** |
| ID | An internally assigned unique ID. |
| Name | User assigned name. Can be modified anytime. |
| Status | - Normal
- Creating
- Deleting
- Partial/Failed – At least one of the underlying RAID Groups has failed, or the Pool metadata cannot be initialized at Start Of the Day. |
| Comment | User free text comment. Can be used for labels, reminders or any other purpose. |
| Type | - IOPS-Optimized
- Balanced
- Throughput-Optimized |
| Raid Group(s) | RAID Group name, or “Multiple (X)” where X denotes the number of RAID Groups in the Pool. |
| SSD Cool Off | Period (hours) of repeated access to a data chunk in the Pool. Used for automatically determining tier placement for data chunks. |
| Created | Date & time when the object was created. |
| Modified | Date & time when the object was last modified. |
| | **Physical Capacity** |
| Usable Capacity | Total capacity of all RAID Groups in the Pool. |
| Used Capacity | The total size of all data written in the Pool *Used Capacity = Used by Volumes + Used by metadata + Used by data copies* |
| Used by Volumes | Capacity used to store the Volumes data. |
| Used by Data Copies | Capacity used to store Snapshots and Clones. |
| Used by Metadata | Capacity used to store the Pool’s metadata. |
| Currently Inactive | Capacity of the Pool’s data chunks that are currently not being accessed. |
| Free Capacity | Available Capacity in the Pool that can be used for new Data and Metadata writes. |
| Physical Capacity
State | - Normal
- Alert
- Protected
- Emergency
See [Managing Pool Capacity Alerts](#managing-pool-capacity-alerts) for more details. |
| | **Virtual Capacity** |
| Provisioned Capacity | Sum of Pool’s Volumes and Clones capacities as seen by the hosts. |
| Allocated Capacity | Pool’s allocated address space of all Volumes, Snapshots and Clones. |
| Pattern Capacity | Capacity savings by data blocks with predefined patterns, such as all-zeroes. Blocks that match the patterns are deduped. |
| Effective Capacity | Amount of data written in the Pool by all Volumes and can be accessed by hosts. Not including capacity taken by Snapshots. |
| Block-Virt Metadata
Capacity | Capacity used by the metadata that is required for managing pool allocation space. |
| Free Virtual Capacity
State | - Normal
- Alert
- Protected
- Emergency
See [Managing Pool Capacity Alerts](#managing-pool-capacity-alerts) for more details. |
| | **Capacity Savings** |
| Data Reduction Ratio | Capacity savings by all data reduction techniques. *Data Reduction Ratio = Effective Capacity / Capacity used by Volumes* |
| Dedupe Ratio | Capacity savings by deduplication. |
| Compression Ratio | Capacity savings by compression. |
| Thin Provision Ratio | Capacity savings by thin provisioning technique. *Thin Provision Ratio = Provisioned Capacity / Effective Capacity* |
### RAID Groups tab
Scope: VPSA Storage Array
The **RAID Groups** tab has 2 display styles to present the RAID Groups
allocated to the selected Pool:
* **RAID Groups View**
Click the **RAID Groups View** button to list the RAID Groups allocated
to the selected Pool.
A table lists the following information for each RAID Group:
* Name
* Protection (RAID-1)
* Status
* Contributed Capacity
* **Segments View**
Click the **Segments View** button to display the structure of a
Pool made of concatinated or striped segments.
Click the **Expand** or **Collapse** controls to display the detail or
summary levels.
### Tiers tab
Scope: VPSA Flash Array
The **Tiers** tab displays details of the tier types allocated to the selected Pool.
Each tier type includes the following information:
- **Type** of tier.
- **Members**: RAID Groups or Drives and their capacities, that are members of each tier.
- **Capacity**: Measurements in units for Usable capacity, Used By Volumes, Currently Inactive, and Free.
- **Status**: Operational status of the tier.
- **Utilization**: Progress bar and measurements in percentages: Used By Volumes, Currently Inactive, and Free.
### Volumes and Dest Volumes tabs
These two tabs display the provisioned Volumes and the
Provisioned Remote Mirroring Destination Volumes. Please note that the
Dest Volumes are not displayed in the main Volumes page, since most
operations are not applicable to them. Displaying the list of the Dest
Volumes in the Pools South Panel provides a complete picture of the
Objects that consume capacity from the Pool.
The **Volumes** tab displays the following information:
- Name
- Capacity (virtual, not provisioned)
- Status
- Data Type (Block or File-System)
The **Dest Volumes** tab displays the following information:
- Name
- Capacity (virtual, not provisioned)
- Data Type (Block or File-System)
- Mapped Capacity
- Data Copies Capacity
### Recycle Bin tab
By default when you delete a Volume it moves to a Pool’s Recycle Bin for
7 days until it is permanently deleted. From the Recycle Bin, an
administrator can purge (permanently delete) or restore a Volume.
A Volume in the **Recycle Bin** tab has the same details that were displayed
for it in the **Volumes** tab, before deletion:
- Name
- Capacity (virtual, not provisioned)
- Status
- Data Type (Block or File-System)
### Logs tab
The **Logs** tab displays all event logs associated with this Pool:
- Type of log entry, for example: Information, Warning, or Error.
- Title - details of the logged event.
- Time - the date and time of the logged event.
### Metering tab
The Metering Charts provide live metering of the IO workload associated
with the selected Pool.
The charts display the metering data as it was captured in the past 20
“intervals”. An interval length can be set to one of the following: 1
Second, 10 seconds, 1 Minute, 10 Minutes, or 1 Hour. The Auto button lets you
see continuously-updating live metering info (refreshed every 3 seconds).
Pool Metering includes the following charts:
| **Chart** | **Description** |
|------------------|-------------------------------------------------------------------------------------------------------|
| IOPS | The number of read and write SCSI commands issued to the Pool, per second. |
| Bandwidth (MB/s) | Total throughput (in MB) of read and write SCSI commands issued to the Pool, per second. |
| IO Time (ms) | Average response time of all read and write SCSI commands issued to the Pool, per selected interval . |
### Capacity Alerts tab
The **Capacity Alerts** tab lists the configurable attributes of the Pool
Protection Mechanism.
* VPSA Storage Array capacity alerts:
* VPSA Flash Array capacity alerts, and where they differ:
### Performance Alerts tab
The **Performance Alerts** tab lists the Pool’s configurations for sending alerts when
performance drops below expectations.
See [Managing Pool Performance Alerts](#managing-pool-performance-alerts) for more details.
### Tags tab
Predefined custom tags can be configured in the **Tags** tab.
An example use case for tags is
[Filtering the List of Pools](#filtering-pools-list)
in the center pane.
A tag is identified by its **Tag Name** and has a **Tag Value** associated
with it. A tag can be defined only once for a Pool. However, the same
**Tag Name** can be defined with a different **Tag Value** for other
Pools.
- **Create**: To create a new tag for a Pool, in the Pool’s **Tags**
tab click **Create**, and enter the **Tag Name** and **Tag Value**.
The tag is added to the list of tags in the **Tags** tab.
- **Edit**: To change the **Tag Value** of an existing tag, click on that
tab in the tags list to mark it, and then click **Edit**.
The **Edit Tag** dialog box opens, allowing overwriting of the
**Tag Value**.
- **Delete**: To delete a tag, click on that tag row in the tags list to
mark it, and then click **Delete**. A confirmation dialog box opens.
- **Refresh**: Displays the updated tags list.
## Managing Pool Capacity Alerts
The VPSA’s efficient and sophisticated storage provisioning
infrastructure maximizes storage utilization, while providing key
enterprise-grade data management functions. As a result, you can quite
easily over-provision a Pool with Volumes, Snapshots and Clones, hence
requiring a Pool Protection Mechanism to alert and protect when free
Pool space is low.
The VPSA Pool Protection Mechanism is either time-based or capacity
consumption based. The goal is to
provide you sufficient time to fix the low free space situation by
either deleting unused Volumes/Snapshots/Clones or by expanding the
Pool’s available capacity (a very simple and quick process due to the
elasticity of the VPSA and the Zadara Storage Cloud).
The VPSA measures the rate at which the Pool’s free space is consumed
and calculates the estimated time left before running out of free space.
User-configurable parameters impact alerts and operations
that are performed as part of the Pool Protection mechanism.
Capcity alerts can be viewed and configured in the Pool’s south pane
[Capacity Alerts tab](#capacity-alerts-tab).
The following table lists the default values of the configurable capacity
alert parameters for the VPSA Storage Array
compared with those of the VPSA Flash Array:
| Type | Alert Parameter Name | Alert Measurement | VPSA Storage Array | VPSA Flash Array |
|-----------------------------|-----------------------------------------|------------------------------------------------|----------------------|--------------------|
| Physical | Capacity Alert Threshold | Estimated remaining time to full capacity | 360 minutes | 600 minutes |
| Percentage of used capacity | ✗ | 90% full | | |
| Physical | Capacity Protection Threshold | Estimated remaining time to full capacity | 60 minutes | 180 minutes |
| Percentage of used capacity | ✗ | 95% full | | |
| Physical | Capacity Emergency Threshold | Free capacity less than | 50 GiB | 50 GiB |
| Percentage of used capacity | ✗ | 99% full | | |
| Physical | Capacity Alert Interval | Timeframe to calculate consumption rate | 60 minutes | 60 minutes |
| Virtual | Allocated Capacity Alert Threshold | Estimated remaining time to full address space | ✗ | 360 minutes |
| Virtual | Allocated Capacity Protection Threshold | Estimated remaining time to full address space | ✗ | 60 minutes |
| Virtual | Allocated Capacity Emergency Threshold | Free address space less than | ✗ | 5 GiB |
| Virtual | Allocated Capacity Alert Interval | Timeframe to calculate consumption rate | ✗ | 60 minutes |
### VPSA Storage Array and VPSA Flash Array physical alerts
Scope: VPSA Storage Array and VPSA Flash Array
Labels indicate where there are differences between the default values for
VPSA Storage Array and VPSA Flash Array
configurations of the capacity alert parameters, and for parameters available
only in VPSA Flash Array implementations.
- **Physical Capacity Alert Threshold**
*“Alert me when it is estimated that the Pool will be at full physical
capacity in X Minutes.”*
The estimated time (in minutes) before running
out of free space. When triggered, an online support ticket is
submitted and an email is sent to the VPSA user. When crossing
this threshold the Free Capacity State changes to “Alert” and the
available capacity will be shown in Yellow. A secondary “reminder”
ticket and an email will be generated when only half of this threshold’s
estimated time is left.
- Estimated time to reach full capacity.
- Default:
- 360 minutes (6 hours) VPSA Storage Array
- 600 minutes (10 hours) VPSA Flash Array
- Minimum: 1 minute (0 means disable this time-based alert)
- Used capacity percentage (for VPSA Flash Array only):
In addition to the time calculation, a VPSA Flash Array
can also track the Pool’s used capacity percentage, and issues an
alert on reaching either the time or percentage threshold, whichever
is first.
- Default Percentage: 90% full
- Minimum: 1 % (0 means disable this percentage-based alert)
- **Physical Capacity Protection Threshold**
*“Do not allow new Volumes, Shares, or Snapshots to be created when it
is estimated that the Pool will be at full physical capacity in X
Minutes.”*
The estimated time (in minutes) before
running out of free space. When triggered, the VPSA starts blocking the
creation of new Volumes, Snapshots and Clones in that Pool. A support
ticket and email are also generated. When crossing this threshold, the
Free Capacity State changes to “Protect” and the available capacity
will be shown in Red.
- Estimated time to reach full capacity.
- Default:
- 60 minutes (1 hour) VPSA Storage Array
- 180 minutes (3 hours) VPSA Flash Array
- Minimum: 1 minute (0 means disable this time-based alert)
- Used capacity percentage (for VPSA Flash Array only):
In addition to the time calculation, a VPSA Flash Array
can also track the Pool’s used capacity percentage, and issues an
alert on reaching either the time or percentage threshold, whichever
is first.
- Default Percentage: 95% full
- Minimum: 1 % (0 means disable this percentage-based alert)
- **Physical Capacity Emergency Threshold**
*”Delete Snapshots, starting from the oldest, when there is less than
the following capacity left in the Pool.”*
When the Pool’s free capacity drops below
this fixed threshold (in GiB),
the VPSA starts freeing Pool capacity
by deleting older Snapshots. The VPSA will delete one Snapshot at a
time, starting with the oldest Snapshot, until it exceeds the
Emergency threshold (i.e. when free capacity is greater than the
threshold). A support ticket and email are also generated. When this
threshold is crossed the Free Capacity State changes to “Emergency”
and the available capacity will be shown in Red.
- Free capacity less than:
- Default: 50 GiB
- Minimum: 1 GiB
- Used capacity percentage (for VPSA Flash Array only):
In addition to the free capacity amount, a VPSA Flash Array
can also track the Pool’s used capacity percentage.
On reaching either the capacity amount or percentage threshold, whichever
is first, the VPSA issues an alert and proceeds with snapshot deletion
until free capacity drops below the Emergency threshold.
- Default Percentage: 99% full
- Minimum: 1 % (0 means disable this percentage-based alert)
- **Physical Capacity Alert Interval**
*“Time estimations above are based on capacity usage during the last X
minutes.”*
The size of the window (in minutes) that is used
to calculate the rate at which free space is consumed. The smaller
the window is, the more this rate is impacted by intermediate changes
in capacity allocations, which can result from changes in workload
characteristics and/or the creation/deletion of new Snapshots and
Clones.
- Default: 60 minutes (1 hour)
- Minimum: 1 minute
### VPSA Flash Array allocated capacity alerts
Scope: VPSA Flash Array
In addition to the physical capacity alerts, the VPSA Flash Array also provides
configurable thresholds to alert in cases where the Pool allocation
(virtual address space) is near capacity.
*Free Address Space = Allocation Limit – Allocated Capacity*
The following user-configurable parameters impact alerts and operations
that are performed as part of the VPSA Flash Array Pool Protection mechanism:
- **Allocated Capacity Alert Threshold**
*“Alert me when it is estimated that the Pool’s address space will be
at full capacity in X Minutes.”*
The estimated time (in minutes) before running
out of free address space. When triggered an online support ticket is
submitted and an email is sent to the VPSA user. When crossing
this threshold the Allocated Capacity Alert Mode changes to “Alert” and the
available address sace will be shown in Yellow. A secondary “reminder”
ticket and an email will be generated when only half of this threshold’s
estimated time is left.
- Default: 360 minutes (6 hours)
- Minimum: 1 minute (0 means disable this alert)
- **Allocated Capacity Protection Threshold**
*“Do not allow new Volumes, Shares, or Snapshots to be created when it
is estimated that the Pool’s address space will be at full capacity in
X Minutes.”*
The estimated time (in minutes) before
running out of free address space. When triggered the VPSA starts blocking the
creation of new Volumes, Snapshots and Clones in that Pool. A support
ticket and email are also generated. When crossing this threshold, the
Allocated Capacity Alert Mode changes to “Protect” and the available address space
will be shown in Red.
- Default: 60 minutes (1 hour)
- Minimum: 1 minute (0 means disable this alert)
- **Allocated Capacity Emergency Threshold**
*”Delete Snapshots, starting from the oldest, when there is less than
the following free address space left in the Pool.”*
When the Pool’s free address space drops below
this fixed threshold (in GiB), the VPSA starts freeing Pool capacity
by deleting older Snapshots. The VPSA will delete one Snapshot at a
time, starting with the oldest Snapshot, until it exceeds the
Emergency threshold (i.e. when free address space is greater than the
threshold). A support ticket and email are also generated. When this
threshold is crossed the Free Capacity State changes to “Emergency”
and the available address space will be shown in Red.
- Default: 5 GiB
- Minimum: 1 GiB
- **Allocated Capacity Alert Interval**
*“Calculate the estimated time until the Pool’s address space is full
based on new capacity usage in the previous X minutes.”*
The size of the window (in minutes) that is used
to calculate the rate at which free address space is consumed. The smaller
the window is the more this rate is impacted by intermediate changes
in capacity allocations, which can result from changes in workload
characteristics and/or the creation/deletion of new Snapshots and
Clones.
- Default: 60 minutes (1 hours)
- Minimum: 1 minute
## Managing Pool Performance Alerts
A VPSA administrator has the option to set Pool Performance Alerts in
addition to the default Pool Capacity Alerts. Performance Alerts are
available for:
**Read IOPS Limit** – Creates an alert when the average read IOPS,
during the past minute, for a Pool exceeds a user-specified threshold.
**Read Throughput Limit** - Creates an alert when, during the past minute,
the average read MB/s for a Pool exceeds a user-specified threshold.
**Read Latency Limit** – Creates an alert when, during the past minute,
the average read latency for a Pool exceeds a user-specified threshold.
**Write IOPS Limit** – Creates an alert when, during the past minute, the
average write IOPS for a Pool exceeds a user-specified threshold.
**Write Throughput Limit** - Creates an alert when, during the past
minute, the average write MB/s for a Pool exceeds a user-specified
threshold.
**Write Latency Limit** – Creates an alert when, during the past minute,
the average write latency for a Pool exceeds a user-specified threshold.
## Deleting a Pool
The VPSA administrator can delete delete a specific Pool if it not needed by
clicking the **Delete** option under the Pool top option menu.
Due to the sensitivity of the operation the system will block a delete request
where the underlying entities (Volumes and Snapshots) still exist.
The VPSA has a built-in Recycle-Bin mechanism that protects against human error
(enabled by default). The Pool cannot be deleted where Volumes are stored in the
Recycle Bin (Pool level). If you wish to delete the Pool, ensure that all Volumes
are Purged from its Recycle Bin.