> I thought upperdir is now optional but must be read-write if one is specified. I have two file systems that I need to create a union for. The upperdir overrides the lowerdir, hence replacing its content. Therefore, regardless if the upperdir is optional, I do need it in this use case. Per the documentation: "A read-only overlay of two read-only filesystems may use any filesystem type." I understood that my use case is possible. However, it does contradict the actual implementation, "overlayfs: workdir and upperdir must reside under the same mount" and your statement, of course. Thanks, Iyad On 04/20/2015 04:01 PM, A. Wan wrote: >> Hi Neil, >> >> Regarding the overlayfs implementation, I am interested in overlaying >> two squashfs file systems, read-only, and running into a problem with >> location of the work directory: >> >> "overlayfs: workdir and upperdir must reside under the same mount" >> >> Since the upper directory is read-only, and it is mounted on a partition >> as such, having writable work directory is not possible. Any suggestions >> on how to utilize overlayfs in this scenario? >> >> I feel this restriction is overkill for the feature. >> >> -- >> Thanks, >> Iyad > I thought upperdir is now optional but must be read-write if one is > specified. Therefore if you want the whole stack read-only specify only > lowdirs and skip the upperdir. Correct me if I am wrong. > > Alex > > > > > ��.n��������+%������w��{.n�����{���w���jg��������ݢj����G�������j:+v���w�m������w�������h�����٥