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    E-MapReduce:Instructions for tiered storage commands

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    E-MapReduce:Instructions for tiered storage commands

    Last Updated:Mar 26, 2026

    Starting from E-MapReduce (EMR) V3.30, JindoFS provides tiered storage. Use tiered storage commands to move data between local disks and OSS storage classes to balance access speed against storage cost.

    All tiered storage commands are asynchronous — they submit a task and return immediately. To monitor progress or wait for completion, use the Status command.

    Prerequisites

    • EMR cluster version V3.30 or later

    Storage classes

    OSS provides three storage classes. Choose a class based on how frequently data is accessed:

    Storage class Access speed Cost Best for
    Standard Fastest Highest Hot data accessed frequently
    Infrequent Access (IA) Fast Lower Warm data accessed less than once a month
    Archive Requires restore (up to 1 day) Lowest Cold data accessed rarely

    For more information about OSS storage classes, see Overview.

    Storage class transitions

    From To Command
    Local disk OSS Standard uncache
    Local disk OSS IA archive -i
    Local disk OSS Archive archive -a
    OSS Archive OSS Standard unarchive
    OSS Archive OSS IA unarchive -i
    OSS Archive Temporarily readable unarchive -o
    OSS Standard Local disk cache

    Commands

    Cache

    Back up data at a path to local disks. After caching, reads are served from local disks instead of OSS.

    jindo jfs -cache -p <path>
    Option Description
    -p Pin local data so it is not evicted based on disk usage

    Uncache

    Remove the local disk backup for a path. Data is retained only in OSS Standard storage.

    jindo jfs -uncache <path>

    Archive

    Move data off local disks and into OSS Infrequent Access (IA) or Archive storage. The local disk backup is deleted after the data is moved.

    jindo jfs -archive -i|-a <path>
    Option Target storage class
    -i Infrequent Access (IA)
    -a Archive

    Unarchive

    Convert data from Archive storage to a more accessible storage class, or temporarily restore it for reading.

    jindo jfs -unarchive [-i|-o] <path>
    Option Target storage class Notes
    *(none)* Standard Default behavior
    -i Infrequent Access (IA)
    -o Temporarily readable Data becomes readable within one day; not a permanent storage class change

    Status

    View the progress of a tiered storage task.

    jindo jfs -status [-detail|-sync] <path>
    Option Behavior
    *(none)* Show the number of files targeted for tiered storage in the directory and the data to which tiered storage has been applied
    -detail Show per-file storage progress
    -sync Block until the tiered storage task completes, then exit

    Because all tiered storage commands are asynchronous, use -sync in scripts that must wait for a task to finish before proceeding — for example, archive data and then validate the result.

    ls2

    View the storage class of files at a path. The ls2 command extends the standard Hadoop ls command with a storage class column.

    hadoop fs -ls2 <path>

    Example output:

    drwxrwxrwx  - -         0    2020-06-05 04:27 oss://xxxx/warehouse
-rw-rw-rw-  1 Archive   1484 2020-09-23 16:40 oss://xxxx/wikipedia_data.csv
-rw-rw-rw-  1 Standard  1676 2020-06-07 20:04 oss://xxxx/wikipedia_data.json

    The third column shows the storage class of each file. Possible values: Standard, Archive.

    Get help

    Run the following command to view help information for tiered storage commands:

    jindo jfs -help archive