Hello T.W. "T.W.": > It seems from trying to run lsattr/chattr on an aufs mount, that the > extended attributes aren't supported. For example: > > ~$ chattr +a .bash_history > chattr: Inappropriate ioctl for device while reading flags on .bash_history > > Is this correct or is there a feature I am missing or misusing? If it > is correct, is it possible for AUFS to support these when the > underlying branches are on filesystems that support it?
Currently aufs doesn't support ext[2-4] specific attributes. (Strictly speaking they are different from XATTR) The reason is to protect users from confusion. For example, you have a lower readonly ext2 and a upper writable tmpfs. - /u = /tmpfs + /ext2 - /ext2/fileA exists but /tmpfs/fileA doesn't - so we can see fileA through /u/fileA And if aufs supported these attributes, then "lsattr /u/fileA" will work. But if you modify fileA, aufs will copy-up it to the upper tmpfs. As you know, lsattr doesn't work on tmpfs. This is the case which make users confused I am afraid. Generally speaking, any FS specific feature is hard to support for aufs. Ext[2-4] attributes is typical one. XATTR is too, but it is going to be generalized and I am considering to begin supporting it. Users may wonder "All my branches are ext2, so the attributes are always available. Why aufs stops me using it?" Actually I have thought about such use-case and had a plan to implement a new feature which enables these attributes when all the branches are extN. It is just pending now. J. R. Okajima ------------------------------------------------------------------------------ Create and publish websites with WebMatrix Use the most popular FREE web apps or write code yourself; WebMatrix provides all the features you need to develop and publish your website. http://p.sf.net/sfu/ms-webmatrix-sf
