This is documentation for MapR Version 5.0. You can also refer to MapR documentation for the latest release.

Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

However, in Version 5.0, you can upgrade old pre-4.0.2 volumes to the new format by using the maprcli volume upgradeformat command. After running this command on a specific volume, you can use the volume as a read-only or read-write volume by following standard procedures. New volumes that you create in Version 5.0 are created in the new format and are promotable automatically. You can continue to use old volumes as they are with no loss of functionality, but they will not be promotable.

...

After upgrading a cluster to Version 5.0, fully enable support for read-write mirrors (promotable mirrors) by setting both of the following parameters to 1 (true). Use the maprcli config save -values command to set these parameters.

 

Parameter

Default Value

Enables/Disables

mfs.feature.rwmirror.support

1 (true) for Versions 5.0, 4.1, and 4.0.2

0 (false) for earlier versions

Support for the read-write mirror feature (promotable mirrors)

mfs.feature.volume.upgrade

0 (false)

Ability to upgrade old-type volumes so they can be used as read-write mirrors

 

...

You can check the status of your volumes in terms of their “mirror type.” The maprcli volume info command returns the following mirrortype values:

 

mirrortype

Description

Volume upgrade required (to support promotability)

0

Old-format volume, created in an earlier release and present in the cluster after an upgrade to Version 5.0

Yes, if the volume is intended for use as a read-write mirror.

1

An old-format mirror volume whose source volume is a type 0 volume (in any MapR version). These mirror volumes cannot be upgraded.

No, not allowed. The maprcli volume upgradeformat command returns an error for these volumes.

2

New-format mirror volume that may be promoted to read-write (no upgrade command required).

No, not needed. These volumes are already in the new format and are promotable.

3

New-format standard volume: either created new in 5.0 or upgraded in 5.0 via the maprcli volume promote command.

No, not needed. These volumes are already in the new format and are promotable.

To check the mirror types for your volumes in Version 5.0, run the following command:

...

Code Block
root@node-20:~# maprcli volume upgradeformat -name vol999 -json
{
 "timestamp":1433465410299,
 "timeofday":"2015-06-04 05:50:10.299 GMT-0700",
 "status":"OK",
 "total":0,
 "data":[
 ]
}

After the promote upgradeformat command has been run, the volume’s mirror type is now 3:

...