Cloud Backup Review – BackBlaze, CrashPlan, Mozy

Cloud Backup Review – BackBlaze, CrashPlan, Mozy

Our Cloud Backup Review recommends BackBlaze as the best cloud backup provider, with CrashPlan second. Note that as of August 2017 CrashPlan no longer does home PC backups, but you can use their small business backup option. This article goes into what to consider when choosing a cloud backup provider, and compares cloud backup providers and cloud storage providers.

Cloud Backups

Online backups are great. You download the software, you pay the fee, and your important documents are backed up over the Internet. It’s incredibly convenient, you can do it all without having to move. If something happens to your data you can download it, or some will ship it to you on a disk.

It’s worth mentioning the difference between online backups and online storage. CrashPlan, BackBlaze, Mozy, and others are backup providers. They provide software that’s made to back up your data to their data center. Dropbox, Amazon S3 and Glacier, and BackBlaze B2 are storage providers, which let you store any files you like. Some provide software, but it doesn’t tend to be a full featured backup client. You can backup to these storage providers using the backup tools we’ve reviewed.

Factors for Choosing an Online Backup Provider

Some providers are better than others, how’s the average person meant to tell which one to use? Most likely you use the one that a friend recommends, or you read an online review like this one.

Here’s what I think is important in an online backup provider:

  • They must backup up the data on your internal disks, and ideally should be able to back up network shares and external disks without requiring them to be permanently connected.
  • They must keep a version history of your files for a minimum of 30 days. Ideally it should be longer than this, though versions can be “pruned” as time goes on. For example if you don’t need backups every two hours that were made a year ago, at that point daily, weekly, or even monthly is likely ok.
  • Data must be compressed before being sent to their cloud storage, and they must offer the option of a custom encryption key.
  • They must not delete your files from backup storage if they’re removed from your computer, other than routine version pruning.
  • Should keep your files for a set number of days after your account is closed or computers are removed from the backup system – 7 to 30 days would be ideal. This protects against viruses that may try to delete your online backups.
  • The backup software should run on a variety of computers and devices – for example Windows 8/10, MacOS, NAS (Network Attached Storage) devices, and maybe even phones.
  • They should offer multi-factor authentication (also known as two factor authentication / 2FA) for logging into the section of their website that lets you restore your data.


The Achilles Heel of Online Backups

Your computer has full access to and authority over online backups. It would be relatively simple for a virus to target the major online backup providers, instructing them to delete all the data you have stored, or even to close your account. A ransomware author knows that if you have online backups you’re less likely to pay their fee to get your data back, so deleting them increases the chances of them being paid. As far as I’m aware this hasn’t happened yet, but it’s only a matter of time.

Some online backup providers delete data from their online storage the moment you remove a folder from your backups, even if they keep a version history. This means a virus could quickly and easily delete all of your online backups.

A simple solution would be for online backup providers to keep all data for a minimum of 30 days after you remove data or delete your account.

Working around Limited Version History

If you want unlimited version history for your files, one solution is to run backup software locally that can create incremental backups, store that backup software’s repository on an internal disk, and have your cloud backup system backup that repository. To reduce total data stored you might not back up these files directly any more, other than perhaps the most important files. Have a read of our blog to find suitable backup software, though there are dozens of products around and most are probably ok.


Update on CrashPlan

CrashPlan announced August 2017 that they will no longer do consumer backups at their relatively low prices. They’re still doing small business and enterprise backups, but that’s a minimum of $10 a month. They’re still a good option if you want things like a full version history.


Online Backup Provider Feature Summary

The following table compares the features of online backup providers

BackBlaze CrashPlan Mozy
Price (monthly) $5 / unlimited $10/month $6/50GB, $10/125GB
Version History 30 days Unlimited 90 days
Client Side Encryption Yes, own key Yes, own key Yes, own key
Internal Disk Backup Yes Yes Yes
Retain Deleted / Removed Files Yes No (removed folders deleted immediately – though I’ve had it reported that they might be retained so test this yourself if it’s key for you) No
Deleted Account File Retention TBC TBC TBC
Platforms Windows/MacOS Windows / Mac / Linux / various NAS Windows / Mac
Backup Network Share No Yes, unsupported Pro only
Client Type Native Java Native
Initial Hard Disk Load / Seed No No Yes
Recovery by Hard Disk Yes No Yes
Additional Features and Notes
  • Unlimited storage.
  • Fast backup using multiple threads.
  • Initial seed of backup from another computer with faster connection possible.
  • Supports multiple backup sets / destinations.
  • Backup to external disk is slow due to validation whenever disk is connected.
Back to internal disk as well as Mozy.

The Best Cloud Backup Provider

To summarise the table above:

  • BackBlaze keeps a shorter version history than others, but keeps deleted files for 30 days. BB will send you a disk if you need to recover a lot of data.
  • CrashPlan is the most flexible, has the most features including backup to internal disks and friends PCs, keeps a long version history, uses a Java client that may be slower than native clients, but removes files as soon as they’re removed from your backup selection. They won’t send you a disk with all your files. They’re more expensive now they discontinued the home product and only do business backup.
  • Mozy keep a good version history, lets you keep a copy of your backup on your PC, but removes files as soon as they’re deleted on your PC. They allow you to send in a disk to seed your backups, and will send you a hard disk with your files.

Based on the criteria above BackBlaze offers the best cloud backup system if you want to be sure your files will be recoverable no matter what.

BackBlaze is our recommend cloud backup service

CrashPlan is second, due to flexibility of their software, but their backups are more vulnerable to theoretical attacks than BackBlaze. Note they’re more expensive than other providers.

CrashPlan is our second place winner

Online Storage Provider Summary

It’s worth mentioning some online storage providers as well. These providers don’t provide backup clients, but you can use software of your choice to back up to them.

  • DropBox is a file storage and distribution service, known for keeping your files in sync across many devices. It keeps a version history of your files, including deleted files, but how much and how long depends on your plan.
  • AWS Simple Storage Service is a file storage and distribution service. It can be configured to keep a version history if you want one, and it can delete old versions based on lifecycle rules. S3 provides very fine grained access control, so for example you can give out write access but not delete access. S3 is a relatively complex system, though software can make it simple to use. S3 lets you serve files over http/s, and can scale to extremely high request rates.
  • BackBlaze B2 is quite similar to AWS S3. It provides a version history and configurable deletion policies. B2 lets you serve files over http/s. B2’s primary point of difference from AWS S3 is low price.
  • AWS Glacier is an online archival system, but it provides absolutely no user interface to view your data. It’s intended for data archival and very infrequent access to data. It does not keep a version history, and the a good approach is to only update, never delete. Like S3 you can apply very fine grained control over access. Glacier is relatively complex and is made for large enterprize use, though software can simplify it for consumer use.


The following table compares the features of online storage providers


BackBlaze B2 Dropbox Glacier (AWS) S3 (AWS)
Provider Type Online Storage, HTTP(s) file serving Online Storage, sync, and file sharing Cold file archival Online Storage, HTTP(s) file serving
Storage Price (month) $0.005/GB

$0.02/GB downloaded

$12.50/2TB $0.004/GB (IA class)

$0.03/GB downloaded


$0.09/GB downloaded

Encryption No – user responsibility AES256 (Dropbox managed keys) AES256 (AWS keys, user managed) AES256 (AWS keys, user managed)
Client Provided Online Sync on Windows,MacOS, Android, iPhone, Linux, others None Online
Compatible Software Small range Huge range Small range including FastGlacier, CloudBerry Backup / Explorer Huge range
File Versioning and retention Yes, flexible Yes, 120 days retention No Yes, flexible
Data Storage Multiple copies in one data center Copies in two data centers Three different data centers, same geographic area Three different data centers, same geographic area
Additional Features Flexible permissions and versioning. Can serve files over http/s. Flexible API. Shares files online. Business plans have additional sharing features.Flexible API, wide compatibility. Retreival time measured in hours. Addressable only by API. Data stored in three facilities. Very flexible access, permissions, versioning. Can serve files over http/s at extremely high rates.Flexible API, wide compatibility. Data stored in three facilities.


These online storage providers are all slightly different. There’s no one provider that will be best for all situations. It’s worth pointing out that Amazon Web Services (AWS) offers by far the largest range of services from their online platform, but the platform is so complex you really need to be trained and certified to become expert in AWS.

Disclaimer: some links in this recommendation may be affiliate links. These were added after the initial review and in no way affect the recommendations.

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2 thoughts on “Cloud Backup Review – BackBlaze, CrashPlan, Mozy

  1. JimB

    Great reviews. As a current CrashPlan Home user I appreciate your comprehensive reviews.

    I wanted to point out that with CrashPlan no longer supporting their Home product, they will no longer have the computer-to-computer option. So you can’t backup to a friend’s computer, as you indicate in the table and summary.

    1. Tim

      Thanks Jim, I just hadn’t gotten around to updating the review. I’ve fixed it up a bit more, and hopefully I’ll get time to look at other cloud backup providers some time, Carbonite and others.