Help & DocumentationElastic MapReduceEMR Development GuideAlluxio Development GuideMounting File System to Unified Alluxio File System

Mounting File System to Unified Alluxio File System

Last updated: 2020-04-03 15:05:17

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Background

Alluxio provides a unified namespace mechanism that allows other file systems to be mounted to the file system of Alluxio. In addition, it allows upper-layer applications to use the unified namespace to access data scattered across different systems.

Operations

bin/alluxio fs mount <alluxio-path> <source-path>

Example 1. Mounting a COS bucket to an Alluxio directory

bin/alluxio fs mount --option fs.cos.access.key=<COS_SECRET_ID> \
    --option fs.cos.secret.key=<COS_SECRET_KEY> \
    --option fs.cos.region=<COS_REGION> \
    --option fs.cos.app.id=<COS_APP_ID> \
    /cos cos://<COS_BUCKET>/<COS_DATA>/

Configure the COS configuration information in --options.

Configuration Item Description
fs.cos.access.key COS scecretId
fs.cos.secret.key COS secretKey
fs.cos.region COS region name such as ap-beijing
fs.cos.app.id User APPID
COS_BUCKET COS Bucket name
COS_DATA COS directory, which can be the root /

This command mounts the COS directory (specified by cos://bucket/xxx) to the /cos directory in Alluxio.

Example 2. Mounting an HDFS directory to an Alluxio directory

bin/alluxio fs mount /hdfs hdfs://data

This command mounts the /data directory of HDFS to the /hdfs subdirectory of Alluxio.

After the mount is successful, the mounted content can be viewed by running the alluxio fs ls command.