The file index, and rebuilding it
What the index on this PC holds, when it updates, how big it gets, and the two buttons that change it: Rebuild index and Forget this set.
Find and Restore work fast, and with the backup drive unplugged, because of one file on this PC: the index. It is a list of what your backups hold, not a copy of it.
What it holds#
For every file in every backup: its path, size, modified date, and whether it has since been deleted from the source. For every backup: its job, destination, the drive's volume serial and label, and when it was last seen. Never the contents of any file.
It lives at %APPDATA%\GBM AI\catalog.db, or %ProgramData%\GBM AI\catalog.db in service mode. The Your file index card on the Find page shows its size: under 100 MB for a million files.
When it updates#
- When a backup completes: the new backup's files are added.
- When the background agent starts, at sign-in or when Windows starts: every destination that answers is checked. Backups found there are added; backups gone from it are marked Removed, and forgotten 30 days later.
- When you open a backup folder from another PC with Restore ▸ Open a backup folder…: its backups are added.
Rebuild index#
Rebuild index at the top of the Find page reads the backups on every job's destination again, from their manifests. The button shows the progress, for example Indexing 6 of 10…, and Find keeps working meanwhile. Use it when:
- Find is missing a backup you know is on a connected drive;
- you copied backup folders between drives by hand;
- the card says Couldn't read the file index.
A rebuild only reads your destinations; nothing on them is written or deleted. Backups on a drive that is not connected are kept in the index as they are. A folder you opened with Open a backup folder… is not a job's destination, so after a rebuild, open it again.
Forget this set#
For a drive that is gone for good, click Forget this set on a Find result marked Drive not connected, Share offline or Removed. That backup leaves Find and Restore on this PC. The confirmation says exactly what happens: Nothing on the drive is deleted; plugging it in and rebuilding the index brings it back.