We had great success adding pigz (multithreaded gzip), symlinking gzip to pigz, then turning off --rsyncable in your backup scripts (not compatible with pigz) and adding a cores limit (in our case 2) in your backup scripts gzip command line.
This sped up backups dramatically (almost linear per core). Perhaps you could add the option to use different compression binaries and options in Proxmox VE 2.0?
This sped up backups dramatically (almost linear per core). Perhaps you could add the option to use different compression binaries and options in Proxmox VE 2.0?