On 10/5/06, Matthew Ahrens <Matthew.Ahrens at sun.com> wrote:
> Jeremy Teo wrote:
> > Hello,
> > request sponsor for #4890717 want append-only files.
> > I have a working prototype where the administrator can put a zfs fs
> > into "append only" mode by setting the zfs "appendonly" property to
> > "on" using zfs(1M).
> > "append only" mode in this case means
> > 1. Applications can only append to any existing files, but cannot
> > truncate files by creating a new file with the same filename an
> > existing file, or by writing in a file at an offset other than the end
> > of the file. (Applications can still create new files)
> > 2. Applications cannot remove existing files/directories.
> > 3. Applications cannot rename/move existing files/directories.
> > Thanks! I hope this is still wanted. :)
> This sounds cool! What would you envision it being used for?
an earlier email from a user on zfs-discuss mentioned the below (which
is when I noticed this RFE)
"Every day we are archiving documents. At the end of the day we want
to freeze the filesystem. Would it be possible to add a time-lock
property to ZFS? Could this be extended to still allow new files to be
added to the locked file system , but not allowing to add/modify files
(ZFS ACL's could handle this)?"
> We're having some discussions about various ways of implementing "append
> only". There are some requirements around Sarbanes-Oxley about
> append-only *files*, and the possibility of using ACLs to specify
> append-only permissions. However, there may also be some use cases for
> append-only *filesystems* as well. Did you have any in mind?
I was under the impression that filesystems were light enough in zfs
for us to use liberally in such a manner (refer to "hack mkdir to
create a zfs" email thread).
Dan Price has a point though; such "append only" functionality could
be added to the generic fs syscalls instead...