Backups
Data safety and security
Data security is an important thing these days, and we take it seriously at Bookhouse. At the core of that endeavour is our secure backup system – a robust and multi-layered set of hardware components supporting numerous scheduled tasks.
Backup systems are a core part of our infrastructure. Our clients enjoy the benefits free perpetual archives – we store every book we create indefinitely, at no cost. We have the proud reputation of still having access to the first book we ever made, and we have never lost a file.
Backups are also encrypted and then stored off site in case of local area disasters, such as fire. Encrypting the data before it is sent to offsite storage means we are not dependent on a third party for data security. Even if someone gained access to the offsite system, they would see nothing but digital gibberish.
Uninterrupted power supplies (UPS) support the backup systems by protecting them from voltage spikes, brownouts and outages. These safeguards ensure the backup systems are always online and operational.
Backup layers
At the lowest level, all of Bookhouse’s data drives exist in a mirrored configuration. Every drive has a twin and all the data written to the drives is written to both drives at the same time. If either of those drives fail, the other one continues without interruption.
Every 15 minutes the data on these mirrored drives is copied in full to a high-speed drive located within the server. This is the primary backup in case both mirrored drives fail at the same time. That’s a highly improbable event, but it’s there just in case.
Every hour the changed files are copied to another separate drive. This gives us an hourly snapshot of all the files which have changed throughout the day.
Every afternoon at 5pm, all files are backed to up a separate, dedicated system: a redundant array of independent disks (RAID). It’s a fancy way of saying multiple drives working together. RAID systems maintain data integrity by combining multiple drives into a unified storage space, with redundant copies of the data distributed across all the drives. This means failure of any one disk does not impact the whole array. Taking this further, Bookhouse uses a special version of RAID which allows up to two drives to fail simultaneously – a highly unlikely event – without impacting the safety of the data.
If a drive fails, it can be replaced without stopping the system and without interruption of service. Bookhouse extends the utility of this idea by using ‘hot spares’. These drives are empty – their only job is to take over in case one of the other drives fail. Hot spares allow the system to repair itself without human intervention.
Early in the morning, not long after midnight, all the files which were changed or created during the day are encrypted, and then uploaded to our offsite storage system. This is an important piece of any data protection policy, in the case of local disasters such as fire or flood. Although these threats are uncommon and unlikely in our area, it is still considered best practice to protect against them.
Encrypting data before uploading is an important detail and one that many companies overlook. This ensures that data cannot be read by intermediate systems as it is transferred to the offsite enclave. We employ the same approach when providing important files to clients during the production process.