Netgear ReadyNAS Misreports Space Usage
A Netgear ReadyNAS may show the sum of file sizes on a volume as being greater than the capacity of the disk.
This may occur if an attempt to copy a file to the volume failed while the copy was in progress. Some examples are:
- Outlook Personal Folder (.PST) files, which can be copied while open, up to the point where Outlook on a workstation has locked the file.
- Files with bad sectors. The copy process continues until reaching the bad sector, then fails.
In both cases, the copy process will allocate the space required for the file in the ReadyNAS file system, then begin copying. When the copy process fails, the destination file is deleted, but then moved by the ReadyNAS to the Recycle Bin folder. Thus the file system still records the “size” of the file as originally allocated but the part of the file that was not copied does not occupy any space. The destination files probably contain correct data up to the failure, and nulls (0x0) thereafter.
These files can be removed as they are of not much use as a backup. If using ROBOCOPY to copy files in this circumstance, the failed files will be dated 1980, as ROBOCOPY does not update the time stamp of the file until the copy process has completed successfully.