September 24, 2025Sep 24 Hi all,I have a question about how Unraid handles hard links when rebuilding a failed data disk from parity.Here’s my understanding so far:- In Unraid, each data disk uses its own file system (XFS/Btrfs/ReiserFS).- Parity is used to reconstruct the entire contents of a failed disk sector by sector.- Hard links exist only within the same disk, since they rely on the file system’s inode structure.My concern:If one data disk fails and is rebuilt using parity, will the hard links that existed on that disk still be preserved correctly? In other words, does the rebuild process restore the file system metadata (inodes) so that the hard links remain intact, or would the linked files be duplicated and end up taking double the storage space?This is very important to me because my NAS is mainly used for PT downloading, where a large number of video resources rely on hard links for renaming in order to be properly scraped by media software, while still keeping the original files intact for seeding.I have not yet purchased Unraid OS because I cannot confirm this issue. Currently, I am using another free NAS system without any form of data protection. However, as my data volume grows, I am starting to consider data security more seriously. Based on my use case, I believe Unraid would be the most suitable system for my NAS, striking the right balance between data protection and storage cost efficiency.If Unraid cannot preserve hard links during a rebuild and instead restores them as duplicate files taking extra space, could you also confirm whether RAID5 behaves the same way in such a scenario?Thanks in advance for clarifying!
September 24, 2025Sep 24 Community Expert Solution 3 hours ago, xemaco said:If one data disk fails and is rebuilt using parity, will the hard links that existed on that disk still be preserved correctly?The rebuild process works at the raw sector level and has no idea of the meaning of the contents of any sector. It therefore rebuilds a disk exactly as it was preserving hard links.
September 24, 2025Sep 24 Author 7 hours ago, itimpi said:The rebuild process works at the raw sector level and has no idea of the meaning of the contents of any sector. It therefore rebuilds a disk exactly as it was preserving hard links.thank you very much
September 25, 2025Sep 25 Author On 9/24/2025 at 4:44 PM, itimpi said:The rebuild process works at the raw sector level and has no idea of the meaning of the contents of any sector. It therefore rebuilds a disk exactly as it was preserving hard links.Can the 4kn and 512e disks be mixing used in the array with parity ?
September 25, 2025Sep 25 Community Expert 9 minutes ago, xemaco said:Can the 4kn and 512e disks be mixing used in the array with parity ?Never heard of any problem doing this. I believe at the top level 512 byte sectors are assumed and mapping this onto what a drive actually supports is handle automatically within the relevant drivers.
September 25, 2025Sep 25 Community Expert 17 minutes ago, xemaco said:Can the 4kn and 512e disks be mixing used in the array with parity ?Yep, not a problem.
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