diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md b/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md index a884ed83905..4459c9475f7 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md +++ b/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md @@ -220,11 +220,14 @@ Below are the details about each command. Limitations ----------- -Certain HDFS file write operations, i.e., `hflush`, `hsync` and `append`, +Certain HDFS operations, i.e., `hflush`, `hsync`, `concat`, `setReplication`, `truncate` and `append`, are not supported on erasure coded files due to substantial technical challenges. -* `append()` on an erasure coded file will throw `IOException`. +* `append()` and `truncate()` on an erasure coded file will throw `IOException`. +* `concat()` will throw `IOException` if files are mixed with different erasure +coding policies or with replicated files. +* `setReplication()` is no-op on erasure coded files. * `hflush()` and `hsync()` on `DFSStripedOutputStream` are no-op. Thus calling `hflush()` or `hsync()` on an erasure coded file can not guarantee data being persistent.