🚀 v0.6.4 — Network Filesystem Ownership Detection

This release fixes spurious ownership warnings on network filesystems (NFS, CIFS, SMB) by implementing intelligent ownership capability testing. The system now automatically detects whether the network server supports chown operations before attempting them.
It addresses NFS root_squash configurations, TrueNAS/Synology NAS compatibility, and improved user experience for network storage backups.

📦 Core Libraries

/lib/storage.sh

Additions

• 🔍 Added test_ownership_capability() function to test chown support on network filesystems
• 🎯 Added automatic ownership capability testing for NFS/CIFS/SMB mounts before attempting chown operations
• 📝 Network filesystems now perform real-world chown testing to detect server configuration

Fixes

• ✅ Eliminated spurious "Failed to set ownership" warnings on NFS shares with root_squash or all_squash enabled
• 🔧 Improved supports_unix_ownership() to perform actual chown testing on network filesystems instead of assumptions
• 🛡️ Network filesystems now automatically detect server configuration (root_squash vs no_root_squash) and adapt behavior accordingly

Behavior Changes

• 🎯 NFS with root_squash (80-90% of cases, TrueNAS/Synology default): Shows info message instead of warning, skips ownership changes
• 📊 NFS with no_root_squash (10-20% of cases, enterprise configs): Proceeds with chown normally, warnings only on real failures
• ✅ CIFS/SMB mounts: Same intelligent detection applies to all network filesystem types
• 🔍 Local filesystems (ext4, xfs, btrfs): Behavior unchanged from v0.6.2
• 🛡️ USB drives (FAT32, EXFAT): Behavior unchanged from v0.6.2

✅ Overall Improvements

• 🎯 Intelligent server detection eliminates confusing warnings for standard NFS configurations
• 🔧 Better compatibility with TrueNAS, Synology, QNAP, and other NAS devices
• 📊 Automatic adaptation to server security policies without user configuration
• 🔍 Real-world testing instead of assumptions about filesystem capabilities
• 🛡️ Preserved security while improving user experience on network storage

✨ Result: Users backing up to NFS/CIFS shares with root_squash (default configuration for most NAS devices) no longer receive misleading ownership warnings. The system automatically detects and adapts to the server's security configuration.

Compatibility: PVE and PBS
Installation: bash -c "$(curl -fsSL https://raw.githubusercontent.com/tis24dev/proxmox-backup/main/install.sh)"
Dev Branch: bash -c "$(curl -fsSL https://raw.githubusercontent.com/tis24dev/proxmox-backup/main/install.sh)" -- dev