Viewing the cluster overview

In the left navigation pane of AOC, click the name of the managed ACOS cluster to go to the cluster Overview page, where you can view information about the cluster and the usage of all resources.

• Alert:

  Displays the type and number of unresolved alerts within the cluster, as well as information about recently triggered alerts.

  Based on severity and urgency, alerts are divided into three types: Critical, Notice, and Info.

  To view details of each alert, click the card to jump to the Alert page. You can also click an individual alert to open its details panel. For more information on alert rule settings and notification management, refer to Managing alert.

• Active-active status:

  If the cluster is an ACOS active-active cluster, you should see its topology status. However, for an ACOS cluster without the active-active feature enabled, this widget will not be displayed.

  • The components and resource information of the active-active cluster, such as the number of hosts and virtual machines in the availability zone (using AVE).
  • The health status of the active-active cluster: Displays the health status of the components in the active-active cluster. Any alert messages will be displayed in the status diagram.
  • The operational status of the active-active components: You can click a component to view its operational status on the pop-up overview page.

• Storage efficiency:

  Displays metrics related to cluster space reduction, including overall storage efficiency, space usage, space reduction ratio, and space reduction savings.

  The overall storage efficiency of a cluster is a measure of the storage capacity optimization that results from the cluster's use of erasure coding, snapshots, and thin provisioning. Overall storage efficiency = Maximum capacity available for all data using replication/Storage capacity used by the cluster.

  Cluster space usage refers to the percentage of the total logical capacity used by all volumes in the cluster to the total storage capacity used by the entire cluster. Space usage = total logical capacity used by all volumes/total storage capacity used by the cluster.

  The space reduction ratio refers to the percentage of space saved within the cluster by using erasure coding instead of replication with the same level of redundancy. Space reduction ratio = Capacity used by replication for all data / Capacity (S) used by current storage redundancy policy (replication or erasure coding) for all data.

  The space reduction amount refers to the storage space saved in the cluster by using erasure coding compared to using replication with the same level of redundancy. Space reduction amount = Capacity used by replication for all data - Capacity (S) used by current storage redundancy policy (replication or erasure coding) for all data.

  Note:

  For volumes using erasure coding, if the configuration is K + M:

  • When M = 1, the replication policy with the same redundancy level is 2 replicas; when 1 < M ≤ 4, the replication policy with the same redundancy level is 3 replicas.
  • Assuming that the physical capacity used by the volume is S, the capacity required by the replication policy with the same redundancy level is S / (K + M) × K × number of replicas.

• CPU:

  Displays information about the current CPU resources of the cluster.

  • The upper-right corner of this area shows:
    • Total frequency: The sum of the CPU frequencies of all hosts in the cluster, for example 998.4 GHz.
    • Total cores: The sum of the physical cores of all hosts in the cluster, for example 384 cores.
  • Click the drop-down symbol to select and view the following CPU information:

    • Usage: The CPU usage of the cluster.

    • Active VM allocation: Show the following 2 allocation ratios:

      Active (shared) allocation ratio = CPU active (shared) allocation/(number of CPUs on all hosts - number of exclusive CPUs - number of system-reserved CPUs). CPU active (shared) allocation refers to the total number of shared vCPUs allocated to all running and suspended virtual machines.

      Shared allocation ratio = CPU shared allocation/(number of CPUs all hosts - number of exclusive CPUs - number of system-reserved CPUs).

    • System reserved: The number of vCPUs reserved for system use.

• Memory:

  Displays the memory usage of the cluster, including total memory, available memory, memory allocated to active virtual machines, and system reserved memory.

• Storage:

  Displays the storage capacity of the cluster, including total storage capacity, used capacity, invalid capacity, available capacity, and estimated maximum capacity allocation.

  Invalid space refers to the sum of the data space capacity provided by unhealthy but online physical disks, nodes with storage failures, and normally unmounted physical disks.

  The estimated available storage space depends on the selected storage policy. By default, the available storage space is displayed when the cluster default redundancy policy is used. When the cluster supports erasure coding, you can select erasure coding and calculate space allocation based on the corresponding space utilization.

  • By replication: The logical space that can be allocated is the available space divided by the number of replicas. For example, when the number of replicas is two, the maximum storage space that can be allocated is 1/2 of the available space.
  • By erasure coding: The maximum capacity allocation is the storage space in the cluster plus space usage corresponding to the erasure code configuration. When the erasure coding configuration is K + M, the space usage is K / (K + M).

• Cache:

  If the cluster uses the tiered-storage mode, the total storage capacity of the cluster, as well as the used, invalid, and available capacity, will be displayed.

  • Total cache:

    Used refers to the amount of cache partition capacity in use and its proportion relative to the total cache partition capacity.

    Invalid refers to the cache partition capacity that cannot be allocated, including the sum of the data space capacity provided by unhealthy and online physical disks, nodes with storage failures, and normally unmounted physical disks.

    Available refers to the remaining cache partition capacity that can be allocated. Available capacity = Total capacity - Used capacity - Invalid capacity.

  If the cluster's node storage is a hybrid flash configuration or an all-flash configuration with various types of SSDs, it will also display the read and write cache capacity for all physical disks in the cluster. Additionally, it will show the capacity data for these two types of cache categorized by the Used, Invalid, and Available states. The ratio of total read cache capacity to total write cache capacity is 2:8.

  • Read cache:

    Used refers to the amount of read cache partition capacity in use and its proportion relative to the total read cache partition capacity.

    Invalid refers to the read cache partition capacity that cannot be allocated.

    Available refers to the remaining read cache partition capacity that can be allocated. Available read cache capacity = Total read cache capacity - Used read cache capacity - Invalid read cache capacity.

  • Write cache:

    Used refers to the amount of write cache partition capacity in use and its proportion relative to the total write cache partition capacity.

    Invalid refers to the write cache partition capacity that cannot be allocated.

    Available refers to the remaining write cache partition capacity that can be allocated. Available write cache capacity = Total write cache capacity - Used write cache capacity - Invalid write cache capacity.

  If the cluster has volume pinning enabled, it also shows the total capacity reserved for pinned volumes and its percentage of the total cache capacity.

  • Volume pinning:

    Displays the total cache partition capacity reserved for pinned volumes, the cache partition capacity used by pinned volumes, the available cache partition capacity for pinned volumes, and the percentage of total capacity that each represents.

    Used refers to the total cache partition capacity used by pinned volumes. In some cases, the used capacity may exceed the total reserved capacity (for example, when a disk is being removed). In this case, an alert may be triggered that the pinned volumes in the cluster occupy too much cache space.

    Available refers to the remaining cache partition capacity that can be allocated to pinned volumes. Available capacity (pinned volumes) = Total reserved capacity - Capacity used by pinned volumes. When the used capacity exceeds the total reserved capacity, the available capacity is 0.

    Maximum capacity allocation refers to the maximum logical capacity that can be allocated to pinned volumes calculated based on the specified numbers of replicas.

• Storage performance:

  The storage performance of the cluster in the read, write, and total (read + write) scenarios is displayed in the form of a line chart, including the following metrics:

  • IOPS
  • I/O average latency
  • I/O bandwidth
  • I/O average block size

• Dynamic resource scheduler (DRS):

  Displays the resource load status of an ACOS (AVE) cluster when the DRS feature is enabled for that cluster.

  The cluster's DRS score is the average DRS score of all running virtual machines in the cluster and is used to evaluate the overall resource balance status of the cluster. A higher DRS score indicates more balanced resource usage in the cluster.

  If there are currently unexecuted migration recommendations, you will also see the number of migration recommendations to be executed.

• Data recovery:

  Displays the amount of data to be recovered for the cluster that is currently undergoing data recovery, as well as the recovery rate.

• VM:

  Shows the total number of virtual machines in the ACOS (AVE) cluster, as well as the number of virtual machines in various states.

• Host:

  Shows the total number of hosts in the cluster and the number of hosts in various states.

• Physical disk:

  Shows the total number of HDD and SSD drives in the cluster and the number of drives in various states.

• Cluster:

  Shows the cluster's version information, license type, software, CPU architecture, mode (RDMA/Boost), and other related information.

• Recycle bin:

  Shows the number of virtual machines in the recycle bin for the ACOS (AVE) cluster, the storage capacity they occupy, and the amount of space that will be freed up over the next seven days.