Managed Backups don't work

Managed Backups either gets stuck at some point or it returns the error being actually a homepage of the site with no real error message. This issue had already been investigated before with no solution and the plugin had been removed from the site for some time. It's been added back and the issue is still there.

  • Dimitris

    Hello there T. Webb,

    hope you're doing good today! :slight_smile:

    I can see that my colleague from Second Level Support team, Mahlamusa, had reviewed this report and provided a reply here
    https://premium.wpmudev.org/forums/topic/snapshot-not-running-1#post-1281594
    about the I/O limits of the server you're using.

    I've already created a new report and pinged Mahlamusa again on this, just in case he could provide any additional information. Your patience here is highly appreciated!

    Warm regards,
    Dimitris

  • Lindeni Mahlalela

    Hello T. Webb

    I hope you are doing great today. Thank you for your patience as we were looking into this and I am deeply sorry that this is not working for you yet.

    I have tried various combinations of Snapshot configurations and all of them seem to fall to the same issue. The issue is still the I/O Usage which doesn't seem to have been upgraded on your hosting account, it still looks the same. See this screenshot I took today while running Snapshot:

    [image pos="0"]

    When this error is reached, it results in the following error in the Managed Backups page:

    It is still evident that I/O Usage is the only server limitation that causes the issue. I have tried the various backup modes by adding some configs in wp-config.php and they all run into the same issue which is an indication that we may have no luck getting this to work unless we get the I/O Usage limit raised.

    I have added this line of code, which uses system commands instead of PHP to create the backup. It seems to be faster on the Database stage but runs into the I/O usage limit once it starts to process files.

    define('SNAPSHOT_ATTEMPT_SYSTEM_BACKUP', true);

    I have then changed to use the other config options available for Snapshot:

    define('SNAPSHOT_FILESET_CHUNK_SIZE', 20);
    define('SNAPSHOT_TABLESET_CHUNK_SIZE', 100);
    define('SNAPSHOT_FILESET_LARGE_FILE_SIZE', 104857600); //~100MB
    if (!defined('SNAPSHOT_FORCE_ZIP_LIBRARY')) define('SNAPSHOT_FORCE_ZIP_LIBRARY', 'pclzip');
    if (!defined('SNAPSHOT_IGNORE_SYMLINKS')) define('SNAPSHOT_IGNORE_SYMLINKS', true);

    And still no luck, it always runs to the same issue. I have even raised the max_execution_time limit (should give the script enough time to complete) by changing the value in the .user.ini file and that did not make a difference which proves time limit is not the issue as the plugin runs into errors before running out of time.

    If by any chance possible, please upgrade your hosting account to one that has much higher limits and it should work.

    I hope this helps.

    Have a nice day.
    Mahlamusa

  • Lindeni Mahlalela

    Hello T. Webb

    I hope you are doing great. Thanks for the response and for the feedback.

    Maybe I should explain how the I/O Usage works first. Basically, I/O Usage (Input / Output Usage) determines the amount of read and write operations on the hard drive of your server, this is usually calculated in kilo bytes per second (1024kbs). This limits the amount of data that can be read or written to the hard drive. If the server is not processing any files then cPanel will show a 0 in the I/O Usage page because there are currently no files being processed on your account on the server. So it will remain at 0 until you start a process that writes or reads to the hard drive many times per second or much data per second.

    In order to see what happens to your I/O Usage please go to your website's WordPress dashboard and run or create a new Snapshot or run a Managed Backup. While the backup/snapshot is being generated please go to your cPanel's home page and refresh it, you will see the stats for I/O Usage will change and if you keep refreshing, it will show different results at some point it will be 100% and at some point it will be less depending on what Snapshot is doing at that time.

    Please see this screen recording to see what I mean: https://www.screencast.com/t/0cDV8Bji5Fgs
    At least see the second and fifth minute of this recording and you will see what happens on the server's I/O Usage when processing Snapshots.

    I have noticed that Snapshot Pro was inactive on your website so I temporarily activated it in order to create this screen cast on the website on which the issue was reported, I have deactivated after the tests I performed, I hope that does not cause any trouble.

    Basically this means if Snapshot is at rest,no I/O Usage because no files are being processed but once Snapshot starts doing something then there will be some I/O Usage. In the screen recording I see that the I/O Usage is a little less than half when processing database but once Snapshot starts processing the media library, plugins and themes then I/O usage shoots up to 100% which essentially means it is reading and writing at about 1.5Mb per second, so if your website is 1Gb it should take plus or minus 11 minutes, but since the I/O Usage shoots up before then it starts to stall because it cannot write any files if the limit is reached.

    Unfortunately, this is a server limitation and there is nothing much we can say besides advice you to upgrade your I/O usage. You should contact your host about this and see what they have to say.

    I hope this clarifies everything. Please let us know if you have any further questions.

    Have a nice day.
    Mahlamusa

  • Lindeni Mahlalela

    Hello T. Webb

    I hope you are doing great today. Thank you so much for the feedback, we really appreciate it.

    I think the first option should be to contact your current host to find out if they can do anything to help. You may refer them to this thread for their reference. Ask them if upgrading your hosting account will make any difference to the I/O Usage limit (in most web hosts this is usually the case), if they say otherwise then you may consider other options.

    About reducing the media library, this can help slightly depending on how the I/O limit is configured, at the rate this is failing there is a small chance that this will make any difference because you might still find out that even if the media library is small but still the server is maxing out the 1.5Mbs input/output. This issue might still persist after reducing the media library but its work a try, this is because I/O Usage is measured per second (or average across a few seconds) not for the total size of the whole website being processed.

    If you do switch to another host then you should ask them first as most hosts do not disclose such limits, they only give unlimited everything but make these limits as they have great impact on the performance of the server, so it would be better to ask first, just to be sure.

    I hope this helps.

    Have a nice day.
    Mahlamusa

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