Storage media

An audit says that a corruption has happened. The age of a disk announces the one to come. The Storage Media screen (group Copies) keeps the inventory of the disks, tapes and spaces that hold your copies, and gives each one a replacement deadline.

The 3-2-1 rule and the three tiers

The 3-2-1 rule recommends three copies of your files, on two different media, one of them offsite. Vault translates it into three tiers:

• T1 · working: the medium you open your files from;
• T2 · local archive: the medium that holds the verified archive, at your place;
• T3 · offsite: the copy elsewhere (online storage, a disk in another place).

When no active medium is declared at a tier, the screen says so: “No active medium at tier …: the 3-2-1 rule is not met.” The Dashboard shows it too. Three new disks at the same tier make only one copy.

Add a medium

1. Click Add Medium.
2. Fill in:
   • Name: your own, the one written on the label (“SSD atelier”, “LTO-8 coffre”);
   • Tier: N1, N2 or N3;
   • Kind: Internal Disk, External Disk, SSD, NAS, LTO Tape, Optical Disc or Cloud;
   • In service since: the date, in AAAA-MM-JJ (YYYY-MM-DD) format;
   • Service life (months): leave empty for the kind’s default (shown in the field);
   • Location: where the medium is (“Bureau”, “coffre de la banque”), for whoever must find it in five years;
   • Notes.
3. Click Save.

Default service lives:

These are orders of magnitude, not manufacturer guarantees: the point is not to predict the failure but to make a deadline exist, because a medium without a deadline is never replaced. Set your own service life if you know better.

An unknown commissioning date stays empty: Vault does not make one up, and the medium is shown as Deadline Unknown.

Read a medium’s state

Each medium shows its tier, kind, location, commissioning date and a state:

• In Service, with “Encore n mois” (n months left);
• Replace Soon: the deadline is less than three months away — time to order, copy and verify without rushing;
• Overdue: the medium may still work, but it is past the accepted risk;
• Deadline Unknown: no commissioning date, or a kind without a deadline;
• Retired.

Media to replace also appear on the Dashboard, the most urgent first.

The line “No verified copy on this medium” — or “n archives, last verified …” — shows the archives verified on this medium, with the date of the last verification and, if any, those that failed.

To attach a copy to a medium: in the medium’s context menu (right click), choose Verify an Archive on This Medium…, then the folder of the .obf archive that sits on this medium. Vault checks the signature and the content fingerprint and records the verdict for this medium. Each medium keeps its copy: verifying the same archive on another medium, or from the Archives screen, does not take it off this one. A stopped verification records nothing.

Retire or delete a medium

In a medium’s context menu (right-click):

• Edit;
• Retire from Service: the medium has been replaced; it stays in the inventory with its history and is no longer counted. Return to Service undoes the retirement;
• Delete…: the medium disappears from the inventory. Verifications made on this medium lose that link. Prefer retiring, which keeps the history.

Adding, retiring and deleting a medium are recorded in the journal.