Hello Bodil and thank you for your continued trust in our products! I am the lead developer of Akeeba Backup and will be taking over this support ticket as it seems to be a bit more technically involved.
The log file tells me that PHP suddenly stopped working when we started scanning the contents of the root directory. I have three possible causes but I need your help in determining which one is plausible.
1. Very old PHP version
. We have determined that PHP versions 5.6.0 to 5.6.5 (and possibly up to 5.6.10) crash inexplicably due to some bugs in the PHP internals (the way it handles the generated opcode before executing it). First check the exact PHP version on each server by going to Joomla's administrator backend, System, System Information and click on the PHP Information tab. The exact PHP version is displayed in big, bold type.
If the site where it works has a newer version (see how to read version numbers
) than the site where it doesn't work you have hit this exact PHP bug. The only solution is to please ask your host to update to PHP 5.6.26, the latest PHP 5.6 version.
2. Too many files and folders
. That's a bit less likely since we have about 100 Mb to store directory information in memory and each file or folder takes up about 2-3Kb. In any case please check how many directory entries (files and folders) you have in your root directory. If it's over about 2000 entries you are hitting a design limitation of the filesystem itself.
Long story cut short, the time for the filesystem itself to list directory contents is exponentially proportional to the number of files. This performance impact is insignificant in the low hundreds of directory entries but becomes measurable when you hit one or two thousand entries. At 8 thousand entries it may take close to half an hour to list the directory contents, especially on a busy filesystem like that on a shared host. Since Apache has a maximum execution limit of about 120 seconds before it kills the child process handling output generation (i.e. PHP) if you have too many directory entries you may end up triggering a hard timeout during the directory scanning phase.
3. Last but not least, we have seen bad hardlinks and symlinks
in one other server. When we tried to list them PHP thew a segmentation fault (it crashed, hard). The crazy thing with these links was that the owner and contents appeared to be different when you listed them using a different PHP API (DirectoryIterator and opendir). All you can do is check if you have symlinks on your site's root and, if you do, try removing them and see if that works. If that works just create the symlinks afresh.
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
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