Monitoring chunk servers

By monitoring chunk servers, you can keep track of the disk space available in the storage cluster. To monitor chunk servers, use the vstorage -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 the following:

CSID
Chunk server identifier (ID).
STATUS

Chunk server status:

active
The chunk server is up and running.
failed
The chunk server process is running but a problem has occured with the CS disk.
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 server was removed by the administrator.
maintenance
The node that the chunk server is located on is in maintenance.
ill
The chunk server experiences slowdown and degrades the cluster performance. The chunk server is isolated from the cluster I/O.
SPACE
Total amount of disk space on the chunk server.
AVAIL
Available disk space on the chunk server.
REPLICAS
Number of replicas stored on the chunk server.
UNIQUE
Number of chunks that do not have replicas.
IOWAIT
Percentage of time spent waiting for I/O operations being served.
IOLAT
Average/maximum time, in milliseconds, the client needed to complete a single IO operation during the last 20 seconds.
QDEPTH
Average chunk server I/O queue depth.
HOST
Chunk server hostname or IP address.
FLAGS

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.