backup still using cache

[pepeverde9]

Hi

I'm using the version of nocache that comes with Ubuntu.
I am making backup of my home directory using tar, something like
nocache tar -zcvp /home -f /mnt/usbhdd/backup.tgz
but when I run
cachestats /mnt/usbhdd/backup.tgz
while running the backup command, it still reports about 3GB of pages in cache.
My understanding was that the used cache should be much smaller. Is there any way to prevent tar and gzip from trashing the cache of the system during backup?

[hhoffstaette]

nocache will only uncache-on-close, i.e. when the large backup.tgz file has been fully written and the last writer closes their file descriptor. The problem is that your backup has only a single file. There is really nothing else that nocache can do in its current form.
See #49