The School Network Backup Window

Both services use the same 100 Mbps link, so the total data they send cannot exceed that capacity. The full backup sends 2 TB every night, most of which is unchanged files, so it consumes a large share of the link for hours. The cameras also need continuous upload, so when the backup saturates the link, camera traffic is delayed. The contended resource is bandwidth, not storage or processing power. This matters because the fix must reduce or schedule bandwidth use, not add disk space. Recognising the shared resource is the first step to a correct solution.

The school should switch from full nightly backups to incremental backups, copying only files changed since the last backup, with a full backup less often. Most of the 2 TB does not change daily, so the nightly transfer would fall sharply, freeing bandwidth for the cameras. The trade-off is that restoring from incremental backups takes longer and depends on a chain of backups, so the school should keep periodic full backups and verify restores. This change addresses the cause, which is unnecessary repeated transfer, rather than the symptom of a slow link.

Giving the backup priority would let backups finish, but it would worsen the camera delay, which is a security concern. Camera footage arriving late may mean incidents are recorded late or lost, so prioritising the backup trades one problem for a more serious one. A better approach is to limit the backup's share of the link or schedule it outside peak camera use, so both services get a guaranteed share. The judgement is that priority is not neutral: it decides who suffers. The manager should weigh the consequence of late security footage against late backups, and the security risk is likely higher.