Backblaze Release 4.0.2

By | May 12th, 2015

Release Date: 5/12/2015
Version 4.0.2

Backblaze version 4.0.2 is out today! The latest Backblaze version is also becoming the minimum version of Backblaze that you can use. As part of this a dialog has been added to the installer to protect against older installers being launched (they will now direct you to download the latest Backblaze version, 4.0.2 or higher).

Additionally we have optimized large file retransmission, especially in cases where a user would have a slower internet connection. This should occur less often.

Finally in the Mac OS X 10.10.4 beta release, the Locate My Computer feature was causing an issue that would use a lot of RAM, this was caused by Apple changing one of the paths that we used to calculate location, resulting in a loop. This has since been fixed and users running Mac OS X 10.10.4 and Backblaze 4.0.2 should no longer be experiencing RAM usage spikes.

Auto-updates will begin rolling out over the next few days. If you’d like the latest version now, please see below for instructions.

Backblaze Online Backup 4.0.2 Details:
Version: 4.0.2 for both Mac OS and Windows.
Availability: 5-12-2015
Cost: Free as an update for all Backblaze customers.
Upgrade Methods:

  • Immediately when performing a “Check for Updates” (Right-click on the Backblaze icon).
  • Immediately as a download from
  • Immediately as the default download on

Questions: Please contact Backblaze Support at



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Category:  Backblaze Bits
  • zang74

    A curious (and problematic issue) and makes me believe there’s a serious bug:

    Somewhere between the release of v4.0 and v4.0.2, my hard drive started having issues. I was getting i/o errors in the console and the computer would halt and become unusable for minutes on end. This made me think my hard drive was failing. Except that three different repair apps showed no issue with the drive. None. All tests passed with flying colours.

    But I still wrote ones and zeroes all over the drive, and proceeded to work from a bottle local backup on an external drive until I could find a suitable replacement drive and install it. Soon enough though, I was having the exact same problem. Which told me it wasn’t a problem with the original drive (it was blank, and unmounted).

    Then that local backup became corrupted; i suspect because as an external drive, its read/write speeds weren’t fast enough and the i/o problem multiplied because of this.

    So I installed anew. Everything was reinstalled. OS, apps, everything. I got an HD restore shipped to me from Backblaze. Thankfully my data was on Backblaze. I haven’t had any slow downs, no I/O errors. Wonderful!

    Except today. And you know what I installed just mere *minutes* before the I/O issues started? Backblaze. Not long after transferring my backup state, it all started again.

    This, to me, is pretty strong evidence that Backblaze is the culprit, and I’m uninstalling it right now until this issue is dealt with. Which makes me horribly sad, because it means that not only will I lose offsite backup, but that the offsite backup is what caused my data corruption and issues to begin with.

  • slovokia

    Yes it’s nice that you released 4.0.2. But I think it still has bugs in it (at least when using multiple threads when uploading large files). I was told that previous 4.0.X releases of the client had bugs that would explain why uploading large files did not work properly. I’ve tried to report what I found but your tech support seems unwilling to consider the possibility that more bugs remain to be fixed.

    At this point I don’t particularly trust your product any more. It is depressing to spend 10 days uploading > 75GB per day and have nothing to show for it. I have found other weird bugs in your product after reinstalling the software and transferring the backup state as your tech support suggested. But I wonder if it is even worth the effort to make a bug report given the likely [minimal] response.

    It would be nice if someone at BackBlaze could actually define what proper operation of your product is. How about putting together a sanity / audit tool that customers could download that would verify the proper functioning of your service from the customers end using the various log files that you produce?

    • Hey there! We can certainly forward the audit suggestion to the engineering team! Support will definitely be the folks to chat with though as they have more access than the social folks. I’ll pass along your suggestion though!

  • Mike Riley

    Can you give any more detail about the optimization to large file retransmission?
    I signed up for Backblaze hoping I could use it to back up my virtual machines (which are split into many ~4GB vmdks), but every time I used one of the machines at all, Backblaze wanted to reupload way too many of the files.

    I ended up having to exclude vmdks from my backup. Would this type of use case be working better in the new version?

    • I have that exact problem. Every time I use a Window virtual machine on my mac, not changing anything, Backblaze backs up the whole VM. I had to take out the whole VM directory from Backblaze, which I’m concerned about, because in the event of a hard drive crash I will have to reinstall the whole thing.

      • druesarn

        I had a similar experience with Parallels VMs. If I used any one of the VMs, Backblaze wanted to upload all of the VMs. So I excluded the VM folder and created a separate VM Backups folder where I’d make a copy of the VM with any significant changes. This takes up more drive space, but I know my VMs are backed up without having to upload multiple VMs every day.

        • slovokia

          Based on my testing BackBlaze version still has bugs when backing up large files (i.e. on the order of > 6GB). This is true even if you have the number of backup threads set to 1. You might check your backblaze log files – if you see messages like “bz_done_ INCONSISTENCY_FOUND” in the bztransmit**.log files (on windows 7 they can be found here: C:ProgramDataBackblazebzdatabzlogsbztransmit) chances are you are running into this problem.

          • EmpireSteve

            Hopefully release (no blog post yet), will fix the large file upload issue. If not, time to look for a service that will handle large files properly. Or give up and stick them on a local external drive and keep fingers crossed.

  • ᅠᅠᅠ

    Is there anywhere we can get more detailed release notes? Thanks!

    • Afraid not, those are all of the changes made to this version.

      • ᅠᅠᅠ

        Alright, thank you! :)