看這篇

https://docs.microsoft.com/en-us/ar...tfs-compression

最下面有提到出現磁碟已滿的問題(注意第3點)

Disk full error during a backup read operation or file copy…

1. NTFS determines which compression unit is being accessed.
2. The compression unit’s entire allocated range is read.
3. If the unit is not compressed, then we skip to step 5. Otherwise, NTFS would attempt to reserve (but not allocate) the space required to write the decompressed CU back to disk. If insufficient free space exists on the disk, then the application might get an ERROR_DISK_FULL during the read.
4. The CU would be decompressed in memory.
5. The decompressed byte range would be mapped into cache and returned to the requesting application.
6. If part of the CU is altered in cache…
----a. The reserved disk space from step 3 would become allocated space.
----b. The CU contents would be compressed and flushed back to the newly allocated region (the LCN location will usually not change).
----c. Any recoverable disk space within the CU would be freed.