What term is used to describe a copy of a file made in case the original is lost or corrupted?

Generally, copying wouldn't harm the original file.

It would be possible that the resulting file arrives corrupt, as a result of a transfer error, be that on the cable, the resulting device, a RAM error, etc.

However, even if when you read the source file into memory, it gets corrupted (and yes, that can corrupt your transfers every time), it should not touch the original file (it doesn't need to write back into disk what is already there).

Thomas makes a good point that while reading the file you may be changing its access time metadata, and that might lead to corruption (quite unlikely imho, and perhaps affecting a different file than the one being read)

It may be more probable that the data was already damaged, and it is only being noticed when you try to read it (which should then cause a copy error as well).

When compared with moving data, copying to a different device, the process will be copy + delete. Here there are two approaches here when dealing with multiple files: The program could copy all the files, then remove the source ones, or it could copy and delete each file as-it-goes (or even per-folder!). If the files are only deleted at the last step, there is no data loss. On the other hand, if the files were moved individually, you would not actually corrupt the files, but you would end up with only some of the files on each device.

When moving files on the same partition, you will actually be changing the pointer to the file data from one location (file path) to another, so the file contents shouldn't be expected to be corrupted, either (of course, if that pointer itself gets corrupted, that would be quite bad, although the risk of certain few bytes corrupting is quite small).

PS: Changing the mode back and forth is probably resetting the mode, this makes me think that it is not properly reset when connecting as it should. This may be solved in the future with a firmware upgrade. In the meantime you probably want to set a different mode as the default, so you only need to do a single switch.

What is Backup?

Backup is the process of creating a copy of the data on your system that you use for recovery in case your original data is lost or corrupted. You can also use backup to recover copies of older files if you have deleted them from your system.

Many businesses and organizations protect their critical data with backup, making it one of the key components of a company’s Disaster Recovery Plan and Business Continuity Strategy.

Data Backup – Why is it important?

Companies and people are very dependent on data. Whereas a person cannot survive without air, water, and food, businesses cannot survive without data. Forty percent of companies that do not have proper backup or disaster recovery plans in place do not survive a disaster.

Every company must designate a Backup Administrator to handle the entire backup strategy, including backup solutions and tools; the backup scope, schedule, and infrastructure; the network and storage, recovery time objectives (RTOs), recovery point objectives (RPOs), etc.

It is extremely important that your company has a backup strategy and solution in place. Otherwise, you can be a statistic.

Data Backup – What to Back Up?

The Backup Administrator’s primary initial task is to understand, define, and manage what data to back up and protect. To reduce the risk of data loss, you want to back up files and databases, but you also want to back up your operating systems, applications, configuration — everything you can. If you use virtualization, you want to back up your hosts and management console, not just your virtual machines (VMs). If you use a cloud infrastructure-as-a-service (IaaS), you want to include that in your scope. And, don’t forget mobile devices — your CEO’s tablet could hold critical company data that can be more important than the data stored on some of your servers.

Revisit your backup scope every time you change the infrastructure. New devices, solutions, services all use data. Your mantra is “back up everything, back up often.”

When you choose a backup solution, be sure that it can protect all your data. Otherwise, some data will go unprotected or you may need multiple backup solutions. For example, if you have a physical server in your data center, a solution that only backs up your VMs isn’t enough. Instead, you need to implement multiple, disparate solutions — or better still — use a solution that backs up every device and system in your backup scope.

Types of data to back up

Every business should back up all important data files and documents including financial data (e.g., credit card transactions, invoices and billings, accounts receivable and payable files, payroll), customer information, vendor information, partner information, communications and email accounts, all applications and databases, project management files, personnel records, the operating system, configuration files, and any other files created by your employees.

Data Backup – RPO and RTO

Once you decide on the scope of your backups, the next important decision is how often you need to back up and define a backup schedule. Your colleagues are constantly changing data, and in the event of a disaster, all the data created from the latest backup to the moment of failure will be lost. This period is called the Recovery Point Objective (RPO) — the maximum period that you are willing to lose data on your systems because of an event.

A shorter RPO means losing less data, but it requires more backups, more storage capacity, and more computing and network resources for backup to run. A longer RPO is more affordable, but it means losing more data.

Many small and medium-sized companies usually define an RPO of 24 hours, which means you need to back up daily. With modern backup solutions, you can implement RPOs as short as a few minutes. You can also have tiered RPOs — shorter RPOs for critical systems, and longer RPOs for secondary systems.

Another important variable is recovery time objective (RTO) — how fast you can recover from the moment of a disaster to the moment you return to normal operations. When systems are down, your company loses money and you need to recover fast to minimize losses. However, as with RPO, a shorter RTO requires faster storage, networks, and technologies – so it is more expensive. For many companies, an RTO of few hours is the norm.

Involve your business stakeholders in discussions on system RPOs and RTOs. Once these are defined, you can decide on your solutions and storage.

Data Backup Solutions

There are multiple types of backup solutions and tools available on the market that deliver different RPOs, RTOs, and handle different scopes. Here are the most popular ones.

Hardware Appliances

These appliances often include storage, which comes as a 19” rack-mounted device that you install and connect to your network. The appliances are easy to install and configure. In most cases, you do not need to provision a separate server, operating system, or install any software. The agents installed on your systems perform the backups, and you access the solution via a graphical interface provided with the appliance.

However, remember that if you have a hardware appliance and it fails, you lose your entire data backup solution. Even if you backed up to a secondary location, you need to re-provision the backup solution before you can recover, which increases your recovery times.

Software Solutions

Software solutions are installed on your own systems and handle the backup process. Many solutions allow you to use existing systems, but some require dedicated servers provisioned just for backup. For these, you need to install and configure the operating system and the backup software. In many cases, you can install the software on a virtual machine (VM).

Compared to hardware appliances, software solutions offer greater flexibility, especially if your infrastructure changes often. Also, software solutions can be less expensive than purchasing a hardware appliance bundle and they also allow you to choose and provision your own storage.

Cloud Services

Numerous vendors offer backup-as-a-service (BaaS) – a cloud-based offering that allows you to provision and run your backups from the vendor’s or service provider’s cloud infrastructure by installing lightweight agents on your machines. The BaaS is even simpler than software because there are no systems to provision and no operating systems to configure.

Of course, if your organization deals with sensitive data or is subject to regulatory requirements, you will need to check if cloud backup with a BaaS solution is acceptable.

Hybrid Data Backup Solutions

The latest innovation in the backup world is all-in-one hybrid backup solution, which gives you the freedom to install the software or use it as a cloud service at will. These solutions combine the best of both worlds, making them the best choice for many organizations.

Different types of data backup

There are three types of data backup vendors offer to ensure the best storage utilization and the best backup / recovery speeds:

Full backups copy everything you wish to protect. Obviously, the first time you back up a system, you want to perform a full backup. But full backups take time, which is why software providers resort to other types of data backup.

Differential backups back up only the files that changed since the last full backup. For example, suppose you do a full back up on Sunday. On Monday, you back up only the files that changed since Sunday; on Tuesday you back up only the files that changed since Sunday; and so on, until the next full backup. Differential backups are quicker than full backups because so much less data is being backed up. But the amount of data being backed up grows with each differential backup until the next full back up. Differential backups are more flexible than full backups, but still unwieldy to do more than about once a day — especially as the next full backup approaches. Differential backups are sometimes called “cumulative incremental backups.”

Incremental backups also back up only the changed data, but they only back up the data that has changed since the last backup — whether that was a full or incremental backup. These are sometimes called "differential incremental backups.”

If you do an incremental backup on Tuesday, you only back up the data that changed since the incremental backup on Monday. The result is much smaller, faster backups. With incremental backups, the shorter the time interval between backups, the less data there is to be backed up. In fact, with sophisticated backup software like Acronis Cyber Protect, the backups are so small and so fast you can actually back up every hour, or even more frequently, depending on the work you're doing and how important it is to have current backups.

While incremental backups give much greater flexibility and granularity (time between backups), they have the reputation for taking longer to restore because the backup has to be reconstituted from the last full backup and all the incremental backups since.

Backup Storage

A copy of your data is stored in backup storage, and you must have it selected, provisioned, and handy for successful backup (and recovery).

Data Backup to Local or USB Disks

If you have enough capacity on your local disks, you can back up to them or to external USB drives. These backups are fast and convenient and you don’t need a network. The downside of local backups is that if the system is destroyed by fire of flood, your backups can be destroyed as well if they are stored in the same location. Also in many cases, you need to manage these backups on a computer-by-computer basis, which makes it cumbersome for larger environments.

Local and USB disk backups are best for quick backups of a small number of systems and are designed for the recovery of individual files or systems in the event of software failure.

Data Backup to Network Shares and NAS

This is one of the most common storage options. With a centralized NAS (Network Attached Storage), SAN (Storage Area Network), or simple network share, you can store many or all company backups in one place and restore a file, system, or the entire data center in the event of a virus attack or data corruption. Yet as with local disks, NAS and SAN will not help you recover data in the event of a major area disaster, such as a hurricane or typhoon that destroys your entire facility.

Data Backup to Tapes

To recover from a major disaster, you must store a copy of your data in an off-site location, preferably at least 100 miles from your primary data center.

One of traditional ways to do that is to store copies of your data on tape devices and physically ship the tapes to a remote location. Modern tape technologies, such as LTO-7, allow you to store up to 2.5TB of compressed data on a single tape, making them quite efficient if you need to protect large amounts of data.

The downside of a tape backup is lengthy RTOs as you need to physically ship the tape back when you need to recover data. Also, some backup solutions have limited recovery options. For example, you can recover an entire system from tape but not a single file or folder. In addition, you need a tape drive, autoloader, or tape library to create backups and perform recoveries and these devices could be relatively expensive.

Data Backup to Cloud Storage

The modern alternative to tape backup is cloud storage. With this type of solution, you subscribe to a certain storage capacity in the cloud vendor’s or service provider’s data center. You do not need any hardware as you do with tape drives, but you do need an internet connection to send backups to the cloud. Your vendor may have ways to eliminate the problems with uploading large amounts of data by offering physical data shipping or initial seeding program.

Data Backup Storage - Which One is the Best?

Every storage solution has drawbacks. To select the right solution, you need to develop a storage strategy based on your unique business requirements, RPOs, and RTOs. You also need a data backup solution that follows the industry-accepted 3-2-1 backup approach — store your data in three places, on two types of storage, with one copy stored off-site. Great examples of the 3-2-1 strategy are disk-to-disk-to-tape (D2D2T) and disk-to-disk-to-cloud (D2D2C) solutions. With these solutions, you back up your data to your central network storage and then copy that same backup to tape or off-site cloud storage.

The 3-2-1 backup strategy

To ensure your data is safe — no matter what happens — you must follow this strategy, which stipulates that you store your data in three places, on two types of storage, with one copy stored off-site. Great examples of the 3-2-1 strategy are disk-to-disk-to-tape (D2D2T) and disk-to-disk-to-cloud (D2D2C) solutions. With these, you back up your data to your central network storage and then copy that same backup to tape or off-site cloud storage.

Why you need a data backup solution?

Your company’s survival depends on the survival of your company data. To implement a reliable data backup strategy, define your business objectives — the backup scope, RPOs, and RTOs; implement proper solutions; provision the storage or combination of multiple storages; and execute and monitor the backups.

Only then can you be sure that your company can continue to safely operate, even when unforeseen events occur.