NextCloudPi - Backups enhancement

I am using NextCloudPi 1.24.1 on a ODROID-H1 with SSD.
I use automatic backups, which are stored on the SSD, including the data and compression. At this time a backup is 70 GB large.
On the backup-page i found some thinks which could be improved.

  1. the size of the backup file is incorrect on the 32bit system ODROID.
    I suggest to replace the php-function with a system call and format the result to get a readable information. To handle the integer overflow works not for lage files. I could make a merge request.
    Is it correct to assume that NextCloudPi only runs on linux devices?

  2. All backup files are listed twice, because /media/USBdrive is a symbolic link to /media/myCloudDrive
    Here the configuration could be checked if the two locations pointing to the same directory.
    The backup dirs could be listet out on the top of the table.

  3. The integrity check of the compressed files while print the list is very slow on my device. It takes more then 10min to create the list of two files with the size of 70 GB. The system has load 4. So i think this operation is also slow on other devices like raspi.
    Could the integrity check be done if i want to use a backup?
    A other solution could be to create a checksum with sha256sum directly after creation of the backup. On the backup-page we check only if the checksum is corret.