Isolated vs shared Storage Vaults

In short

When several devices share one client user account, their backups can go to one shared Storage Vault or to an isolated vault per device. Shared vaults save storage because identical data is only stored once. Isolated vaults keep each device's backups separate, so one device's jobs never hold up another's. For most clients, isolated vaults are the safer default, and that's what the Web Portal recommends.

How it works

The provisioning modes

You choose the mode under Storage Vault Provisioning when you add a user in the Magnus Box Web Portal (Management Console > Users > Add user...):

Provision Storage Vaults automatically, when new devices are registered to this user (recommended): each device that registers gets its own new vault from the chosen Template:. This gives you isolated vaults.
Provision Storage Vaults once, when this user is created: one vault is created with the account, and every device on the account backs up to it. This gives you a shared vault.
Don't automatically provision any Storage Vaults: no vault is created. You add vaults yourself. See Creating Storage Vaults.

For an existing user, open the user's Profile tab and set Automatically create Storage Vaults for newly registered devices: to a template (for example Cloud Storage Vault) to give each new device its own vault, or to (none) to stop creating them. Click Save changes. This only affects devices that register afterwards; existing vaults stay as they are.

A policy can set this for all its users on its Storage Vaults tab, under Automatically create Storage Vault for new devices. See Set default Protected Items and schedules with policies.

Shared vaults

Less storage: data is deduplicated within a vault, so files that exist on several devices (the same installer, the same shared documents) are stored once.
Devices see each other's data: any device on the account can browse and restore the others' backups.
Jobs can wait for each other: a vault is locked during some operations, such as retention passes. While one device holds the lock, another device's backup can be delayed or missed. See Storage Vault Locks.

Isolated vaults

No waiting on other devices: each device's jobs and retention passes only touch its own vault.
Cleaner separation: each device only works with its own vault. The schedule editor hides other devices' vaults unless you tick Show Storage Vaults in use by other devices.
More storage: data isn't deduplicated between devices, so the account uses more space in total.

What this means for you

Use isolated vaults for accounts with several unrelated computers, for laptops that are online at different times, and wherever missed backups would hurt. This also avoids most "locked by another device" errors. See Error "Cannot proceed - Locked by device".
Consider a shared vault when a few devices hold largely the same data and storage use matters more than independence, for example two workstations syncing the same file share.
Storage is what changes. Isolated vaults can increase the total stored for an account, which can affect what the client costs you. See Set storage and usage quotas, and contact support@magnusbox.com for current pricing.
One device per account is simplest. Where it's practical, give each device its own user account. See Best Practices.