Why can’t I upload files with file names of more than 83 Chinese characters (or more than a certain number of other characters)?
Last modified date:
2022-12-21
Under the ext4 file system on QNAP NAS, the size of file names (including the file extension) is limited to 255 bytes.
A regular Chinese character is 3 bytes in UTF-8 encoding, therefore 84 regular Chinese characters are 252 bytes. A file extension of 3 letters adds 4 more bytes (e.g., ‘.txt’, which has 1 byte per ASCII character including the dot). The result is 256 bytes, 1 byte over the limit.
However, the number of bytes per character may vary between different character sets for different languages, as well as within a language (e.g., some special Chinese characters require 4 bytes). And because file extensions can also contain fewer or more than 3 letters, the actual character limit may vary on a case-by-case basis.
