Messages in this thread | | | From | "J. R. Okajima" <> | Subject | Re: [PATCH 6/6] overlay: overlay filesystem documentation | Date | Tue, 19 Apr 2011 12:05:17 +0900 |
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Hello Miklos,
Miklos Szeredi: > +The lower filesystem can be any filesystem supported by Linux and does > +not need to be writable. The lower filesystem can even be another > +overlayfs. ...
When user mounts overlayfs over and over like this, # mount -t overlayfs -o upper=/rw1,lower=/ro1 none /ovl1 # mount -t overlayfs -o upper=/rw2,lower=/ovl1 none /ovl2 ::: # mount -t overlayfs -o upper=/rwN,lower=/ovl{N-1} none /ovlN
And if he modify a file in the bottom RO layer, then overlayfs copies-up the file into each RW layer? - 'fileA' exists in only /ro1. - nested mounts. - run "echo append >> /ovlN/fileA" - is fileA copied-up to /rw1, and then to /rw2, and then ... to /rwN?
If user specify a single dir as every upper laery, then the copyup will be done only once, or such RW layers are not allowed?
J. R. Okajima
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