Shard Backend Migration

This feature helps the administrator move a single shard’s already-existing content to a different backend, for a content store Purpose (DATASTORE or EXTRACTION): use this after already changing that shard’s storage in Shard administration, so content written from then on lands on the new backend, but whatever the shard held before is stranded on the old one. Unlike Global Content Migration, which copies every shard’s content to the one globally-configured destination, this moves one shard’s content to whatever backend that specific shard is now pointed at, and deletes the source copy once safely verified at the destination — the switch is already live, so nothing will read it there again.

Note

Only DATASTORE and EXTRACTION are offered as purposes here (unlike Global Content Migration, which also offers CACHE and OCR_TEMPLATE): those two are the only content kinds this tool can positively attribute to a single shard before moving that content.

Run a migration

• Select the Shard.
• Select the Purpose (DATASTORE or EXTRACTION).
• Select the source backend (From) and destination backend (To) — Filesystem or S3.
• Click the Start button.

Caution

Only one migration can run at a time for the same shard/purpose/direction combination. The migration runs in the background and can take minutes or hours, depending on the volume of data. The progress page refreshes automatically every 2 seconds, showing Found, Copied, Already at destination, Deleted from source, Skipped (.bak), Errors, Bytes copied, the current tenant, and the last error.

Note

The detailed log can also be followed on the progress page, filtered by ContentStoreMigrator.