Monitoring Chunk Servers
By monitoring chunk servers, you can keep track of the disk space available in a Virtuozzo Storage cluster. To monitor chunk servers, use the pstorage -c <cluster_name> top command, for example:
The command above shows detailed information about the stor1 cluster. The monitoring parameters for chunk servers (highlighted in red) are explained in the table below:
Parameter
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Description
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CSID
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Chunk server identifier (ID).
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STATUS
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Chunk server status:
- active. The chunk server is up and running.
- Inactive. The chunk server is temporarily unavailable. A chunk server is marked as inactive during its first 5 minutes of inactivity.
- offline. The chunk server is inactive for more than 5 minutes. After the chunk server goes offline, the cluster starts replicating data to restore the chunks that were stored on the affected chunk server.
- dropped. The chunk serve was removed by the administrator.
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SPACE
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Total amount of disk space on the chunk server.
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FREE
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Free disk space on the chunk server.
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REPLICAS
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Number of replicas stored on the chunk server.
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IOWAIT
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Percentage of time spent waiting for I/O operations being served.
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IOLAT
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Average/maximum time, in milliseconds, the client needed to complete a single IO operation during the last 20 seconds.
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QDEPTH
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Average chunk server I/O queue depth.
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HOST
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Chunk server hostname or IP address.
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FLAGS
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The following flags may be shown for active chunk servers:
J : The CS uses a write journal.C : Checksumming is enabled for the CS. Checksumming lets you know when a third party changes the data on the disk.D : Direct I/O, the normal state for a CS without a write journal.c : The chunk server's write journal is clean, there is nothing to commit from the write journaling SSD to the HDD where the CS is located.
Note: Flags which may be shown for failed chunk servers are described in Failed Chunk Servers.
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