Administrator’s Command Line Guide

4.3. Monitoring Chunk Servers
Note: The FS field shows the size of all user data in the cluster without consideration for replicas.
4.3.2 Exploring Chunk States
The table below lists all possible states a chunk can have.
Status Description
healthy Percentage of chunks that have enough active replicas. The normal state of
chunks.
replicating Percentage of chunks which are being replicated. Write operations on such chunks
are frozen until replication ends.
offline Percentage of chunks all replicas of which are offline. Such chunks are completely
inaccessible for the cluster and cannot be replicated, read from or written to. All
requests to an offline chunk are frozen until a CS that stores that chunk’s replica
goes online.
Get offline chunk servers back online as fast as possible to avoid losing data.
void Percentage of chunks that have been allocated but never used yet. Such chunks
contain no data. It is normal to have some void chunks in the cluster.
pending Percentage of chunks that must be replicated immediately. For a write request
from client to a chunk to complete, the chunk must have at least the set minimum
amount of replicas. If it does not, the chunk is blocked and the write request can-
not be completed. As blocked chunks must be replicated as soon as possible, the
cluster places them in a special high-priority replication queue and reports them
as pending.
blocked Percentage of chunks which have fewer active replicas than the set minimum
amount. Write requests to a blocked chunk are frozen until it has at least the
set minimum amount of replicas. Read requests to blocked chunks are allowed,
however, as they still have some active replicas left. Blocked chunks have higher
replication priority than degraded chunks.
Having blocked chunks in the cluster increases the risk of losing data, so postpone
any maintenance on working cluster nodes and get offline chunk servers back on-
line as fast as possible.
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