Creating a Storage Tier

Describes how to create a sotrage tier using the Control System and the CLI.

For a primer on Data Tiering, see Data Tiering.

You can create a tier using the Control System and the CLI.

When you create a tier, filesystem creates a volume, whose mount point is /var/mapr/tier/mapr.internal.tier.<tiername>, for the tier. For warm tier volumes automatically created using the ecenable parameter or the Control System, by default, a corresponding tier volume named mapr.internal.tier.autoec.<volName>.<creationTime> is created in the /var/mapr/autoectier path. The tier volume is visible and stores all the metadata tables and information on all the jobs running on the tier. Do not modify, move, or remove this volume.

Note: If the number of cluster nodes is more than five, by default, HPE Ezmeral Data Fabric (through the enforceminreplicationforio parameter) requires minimum number of copies of the tier volume for writes to succeed. If the number of cluster nodes is less than five, HPE Ezmeral Data Fabric does not enforce minimum number of copies for writes to succeed.

Creating a Warm Tier Using the Control System

When you create a volume enabled for erasure coding, the control system automatically creates a warm tier and associates the volume with that tier. See Creating a Volume for more information. You cannot create a warm tier separately using the Control System.

Creating a Cold Tier Using the Control System

To create a cold tier:

Log in to the Control System, click Data > Volumes, and then do one of the following:
- Go to the Remote Targets tab if you wish to create a remote target that is not (yet) associated with a volume.
- Click Create Volume if you wish to create a remote target for a volume when you are creating the volume.
  Note: You must enable data tiering and select Remote Archiving (Cold) from the Tiering Type drop-down list to create the remote target.
- Click Edit Volume in the volume information page if you want to create a remote target for the volume when you are editing the volume settings.
  Note: You can create a remote target only if a remote target is already not associated with the volume.
Click one of the following to display the Create Remote Target window.
- Create Target if you are in the Remote Targets tab.
- Create link associated with the Remote Target field if you are in the Create New Volume page.
- Create link associated with the Remote Target field if you are in the Edit Volume page.
Specify a name for the tier in the Remote Target Name field.
Select a topology for the metadata volume associated with the tier from the list of topologies in the Lookup Topology drop-down menu.
The volume stores all the metadata tables and information on all the jobs running on the tier. If many volumes share the same tier (and thus the same lookup topology), the lookups might have an adverse affect by inadvertently adding background load to nodes in that topology. This property allows you to setup the lookups on other nodes.

Specify the following properties.

Vendor	The vendor from the Vendor drop-down list. Note: For cold tiering, HPE Ezmeral Data Fabric supports the following vendors: AWS (Amazon AWS) GCS (Google Cloud Platform) HDS (Hitachi HCP) IBM (IBM Cleversafe) Azure Blob (Microsoft Azure) Others (such as Minio) See Specifying the Vendor/Object Store for a Cold Tier for more information on the supported vendors.
URL	The URL to use to connect to the tier in the following format: `<protocol>://<IP\|hostname>.<domain>` If the protocol is `https`, the MAST Gateway uses HTTPS to upload data to the cold-tier. If the cold-tier storage does not support HTTPS, all tier related operations will fail. If the cold tier does not support HTTPS, set the protocol to `http`. See Specifying the Vendor/Object Store for a Cold Tier for more information on the tier endpoint URLs and supported authentication protocols.
Bucket Name	The name of the bucket on the tier. This cannot be modified once associated with a tier. If the bucket does not already exist on the tier, HPE Ezmeral Data Fabric will attempt to create the bucket. Note: For Azure, the bucket/container is created in the region that is specified in the parent storage account.
Region	The S3 region to create the bucket on. This cannot be modified once configured (explicitly or using the default) and associated with a tier. See region for more information.

Enter the credentials for accessing the tier in the Access Key and Secret Key fields.
Tip: For Azure Blobs, the storage account name is the access key.
Click Create Target to create the cold tier that you can associate with a volume.

Creating a Tier Using the CLI and the REST API

CLI

Run the following command to create a tier:

Cold tier:
```
$maprcli tier create -name <tier_name> -type cold -url <tier_url> -credential <credentials_file_path>
```
For using the -credential option, you must have the credential file already set up as described in Setting up a Credentials File for Connecting to a Cold Tier Using the CLI or REST API. On the other hand, if you do not have the file already set up, use the -credential_str option as follows:
```
$maprcli tier create -name <tier_name> -type cold -url <tier_url> -credential_str '<credential_string>'
```
Warm tier with default values:
```
$maprcli tier create -name <tier_name> -type ectier
```
Note: You can associate the same tier with multiple volumes with different erasure coding scheme.

REST

Send a request of type POST. For example:

Cold Tier:

# curl -k -X POST 'https://abc.sj.us:8443/rest/tier/create?name=egColdTier&type=cold&url=s3.amazonaws.com&credential=credentials.txt' --user mapr:mapr
{"timestamp":1525724933919,"timeofday":"2018-05-07 01:28:53.919 GMT-0700 PM","status":"OK","total":0,"data":[],"messages":["Successfully created tier: 'egColdTier'"]}

Warm tier:

# curl -k -X POST 'https://abc.sj.us:8443/rest/tier/create?name=egWarmTier&type=ectier' --user mapr:mapr
{"timestamp":1525725105206,"timeofday":"2018-05-07 01:31:45.206 GMT-0700 PM","status":"OK","total":0,"data":[],"messages":["Successfully created tier: 'egWarmTier'"]}

Note: You can associate the same tier with multiple volumes with different erasure coding scheme.

For more information, see tier create.