eG Monitoring
 

Measures reported by EMCCtraCapctTest

An EMC Centera cluster consists of three or more hardware nodes. A single rack can hold up to 32 nodes to porvide upto 30.8 TB of raw capacity. Multiple racks can be configured as a single cluster, delivering up to 180 TB of usable storage. If the cluster lacks space, the data cannot be stored in the target storage system which may lead to critical data loss. To avoid this and to ensure peak performance of the cluster, it is mandatory to monitor the space utilization of the cluster periodically. The EMCCtraCapctTest helps administrators in this regard!

This test reports the space available for use in the cluster and space that is utilized in the cluster. By closely monitoring the space utilization of the cluster, administrators may be alerted to potential space crunch at the earliest before the users complain.

Outputs of the test : One set of results for each cluster in the target storage system.

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
numNodes Indicates the total number of nodes in the cluster. Number Storage system should have adequate number of storage nodes to store the data and access nodes to allow quick and easy access to resources.
numNodesStorageRole Indicates the number of nodes in storage node role as opposed to access nodes. Number Storage system should have adequate number of storage nodes to store the data and access nodes to allow quick and easy access to resources.
totalRawCapacity Indicates the total raw capacity available in the cluster. This includes capacity required for system, audit etc. TB If the free raw capacity is low, there will be a shortage of available capacity for upcoming reads and writes which may lead to data loss. You should monitor these number to maintain/add new capacity as and when required. The percentage of capacity provides an idea of how much of capacity is used.
usedRawCapacity Indicates the used capacity available in the cluster. This includes capacity required for system, audit etc. TB If the free raw capacity is low, there will be a shortage of available capacity for upcoming reads and writes which may lead to data loss. You should monitor these number to maintain/add new capacity as and when required. The percentage of capacity provides an idea of how much of capacity is used.
freeRawCapacity Indicates the free capacity available in the cluster. This includes capacity required for system, audit etc. TB If the free raw capacity is low, there will be a shortage of available capacity for upcoming reads and writes which may lead to data loss. You should monitor these number to maintain/add new capacity as and when required. The percentage of capacity provides an idea of how much of capacity is used.
freeRawCapacityPCT Indicates the percentage of free capacity available to use out of total capacity. Percentage If the free raw capacity is low, there will be a shortage of available capacity for upcoming reads and writes which may lead to data loss. You should monitor these number to maintain/add new capacity as and when required. The percentage of capacity provides an idea of how much of capacity is used.
systemBuffer Indicates the buffer size for system reads and writes. TB You can adjust the buffer size to achieve optimal performance for system reads and writes.
regenarationBuffer Indicates the buffer size used for regeneration. TB You can adjust the buffer size to achieve optimal performance for regeneration reads and writes after disk failure.
availableCapacity Indicates the capacity available in the cluster for user data. TB  
totalObjectCount Indicates the total number of objects which can be stored in cluster. Number  
usedObjectCount Indicates the total number of objects addresses which are already used. Number  
freeObjectCount Indicates the number of objects addresses which are already used. Number  
freeObjectCountPCT Indicates the percentage of object addresses free to be used. Percentage  
systemResources Indicates the total capacity allocated for system resources. TB  
offlineCapacity Indicates the storage capacity which is offline at the time of measurement. TB  
spareCapacity Indicates the storage capacity which is spare. TB  
usedCapacity Indicates the storage capacity already used for user data. TB  
auditMetadata Indicates the capacity in the cluster used for audit metadata. TB  
protectedUserData Indicates the capacity overhead required for providing protection to user data against failures. TB