I have Ubuntu 12.04 and when I try to unmount a drive after copying data, the Writing Data to Device takes forever, maybe as long and the copy process? This is another thread about this: Unmounting drive in Xubuntu
As an explanation, I am backing up a file server using rsync, specifically grsync, one large folder at a time. So I finish a 1 TB backup which may take a full day or 24 hours (many small files), simply unmounting the drive can take hours or days when it says it is "writing data to disk". If I kill it then I get file system errors and have to fix them in windows which takes a while.
I tried different disks with similar results. It seems that Ubuntu either does not write or just writes poorly and/or causes file-system errors.
Is it possible to stop this, maybe disable write-back cache or something, just to make sure when I write something to disk, it is written completely without needing to write more when un-mounting. Thank You.