Administrator’s Command Line Guide
Table Of Contents
- Introduction
- Accessing Acronis Storage Clusters via iSCSI
- Preparing to Work with Acronis Storage iSCSI Targets
- Creating and Running Acronis Storage iSCSI Targets
- Listing Acronis Storage iSCSI Targets
- Transferring Acronis Storage iSCSI Targets Between Acronis Storage Nodes
- Stopping Acronis Storage iSCSI Targets
- Deleting Acronis Storage iSCSI Targets
- Configuring Multipath I/O for Acronis Storage iSCSI Targets
- Managing CHAP Accounts for Acronis Storage iSCSI Targets
- Managing LUN Snapshots
- Accessing Acronis Storage Clusters via S3 Protocol
- Monitoring Acronis Storage Clusters
- Managing Cluster Security
- Maximizing Cluster Performance
4.3. Monitoring Chunk Servers
4.3.1.1 Understanding Allocatable Disk Space
When monitoring disk space information in the cluster, you also need to pay attention to the space reported
by the vstorage top utility as allocatable. Allocatable space is the amount of disk space that is free and can be
used for storing user data. Once this space runs out, no data can be written to the cluster.
To better understand how allocatable disk space is calculated, let us consider the following example:
• The cluster has 3 chunk servers. The first chunk server has 200 GB of disk space, the second one — 500
GB, and the third one — 1 TB.
• The default replication factor of 3 is used in the cluster, meaning that each data chunk must have 3
replicas stored on three different chunk servers.
In this example, the available disk space will equal 200 GB, that is, set to the amount of disk space on the
smallest chunk server:
# vstorage -c stor1 top
connected to MDS#1
Cluster ’stor1’: healthy
Space: [OK] allocatable 180GB of 200GB, free 1.6TB of 1.7TB
...
This is explained by the fact that in this cluster configuration each server is set to store one replica for each
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