Background:

Transparent Cloud Tiering (TCT):

TCT leverages the existing Information Lifecycle Management (ILM) policy infrastructure that is available in Scale today that allows Scale administrators can define ILM policies, to tier the data to cloud storage. Cloud storage tier should be used to store cooler data from Scale file system (to store infrequently accessed data).



https://www.ibm.com/support/knowledgecenter/en/STXKQY_5.0.0/com.ibm.spectrum.scale.v5r00.doc/bl1ins_mcstore_intro.htm

Scale Out Backup and Restore (SOBAR):

Scale Out Backup and Restore (SOBAR) is a specialized mechanism for data protection against disaster only for GPFS™ file systems.

https://www.ibm.com/support/knowledgecenter/en/STXKQY_5.0.0/com.ibm.spectrum.scale.v5r00.doc/bl1adv_sobar.htm

TCT – SOBAR Integration:

Transparent Cloud tiering make use of SOBAR functionality to protect the data of file systems that are managed by Transparent Cloud Tiering

TCT leverages SOBAR backup commands to capture meta-data of TCT managed file system. Resultant backup image that consists of several files required during restore, is stored safely in the configured cloud storage, using TCT data sharing service.

In the event of a disaster, access to TCT managed file system data can be restored by restoring the backed-up files from cloud using SOBAR restore commands, on the necessary Spectrum Scale infrastructure.

Only file stub and metadata is restored and not actual data. Actual data is recalled from cloud on need basis, whenever application tries to access the files.

Use Case :



In this example, Site-1 and Site-2 are configured in “synchronous mirroring with GPFS replication” as primary sites (https://www.ibm.com/support/knowledgecenter/en/STXKQY_5.0.0/com.ibm.spectrum.scale.v5r00.doc/bl1adv_gpfsrep.htm), whereas site-3 and site-4 are disaster recovery sites, but with high speed connectivity with primary site.

All 4 sites also share same cloud object storage namespace, using IBM Cloud Object Storage (COS) IDA (https://www.ibm.com/in-en/marketplace/cloud-object-storage-system/details). Transparent Cloud Tiering is installed on 4 sites.

Transparent Cloud Tiering is configured on primary site, to tier data to external cloud storage pool (IBM COS). Also, it is required to carry out regular SOBAR metadata backups to cloud, with “Procedure for backup” in TCT-SOBAR integration section KC link.

Question arises how do we recover the Transparent Cloud Tiering data and made available at Site 3 or Site 4 when disaster happens on Site 1 and Site 2?

The integration of SOBAR with Transparent Cloud Tiering will provide a solution through which last possible backed up data can be restored on site 3 or Site 4.

https://www.ibm.com/support/knowledgecenter/STXKQY_5.0.1/com.ibm.spectrum.scale.v5r01.doc/b1ladm_introsobar.htm

Backup and restore procedures on Primary and Recovery site:

https://www.ibm.com/support/knowledgecenter/STXKQY_5.0.1/com.ibm.spectrum.scale.v5r01.doc/b1ladm_prereqforusingsobar.htm

The below talks about Step by Step procedure for backup of TCT managed file systems on Primary and data restore on Recovery site.

https://www.ibm.com/support/knowledgecenter/STXKQY_5.0.1/com.ibm.spectrum.scale.v5r01.doc/b1ladm_bkupproceduresobar.htm

https://www.ibm.com/support/knowledgecenter/STXKQY_5.0.1/com.ibm.spectrum.scale.v5r01.doc/b1ladm_restoproceduresobar.htm


Special Thanks to Amey P Gokhale/India/IBM, Satishreddy Konala2/India/IBM, Subramanian Nallasivam/India/IBM for providing valuable suggestions.
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