Peter Tribble wrote: > On Fri, Feb 5, 2010 at 8:05 AM, sanjay nadkarni (Laptop) > <Sanjay.Nadkarni at sun.com> wrote: > >> Salutations!! >> >> As part of Solaris Next I am proposing the following changes to /var >> hierarchy to avoid system amnesia across multiple Boot Environments. I >> would appreciate your feedback on caiman-discuss at opensolaris.org. >> > > Thinking about this, it seems to me that the sense of the proposal is the > wrong way round. > > Rather than cherry-picking a small handful of directories to be shared, > wouldn't it be better to share the whole of /var by default, and then exclude > the handful of non-shared locations? > I had played with this approach for while, but in the end I decided to go with the current approach for the following reasons:
1. To reduce the impact applications that may store persistent data that may be incompatible across BEs. For example, Apache 1.3 may have data in BE1 and if the user upgrades to BE2 and moves to Apache2.3, and changes configurations that information may be incompatible if the user decides to revert back. Note that this is a contrived example to illustrate the issue. 2. Control and carry forward what is known. The list of directories there are mostly managed by OS and if format changes occur it can be handled. > The reasons I believe this makes sense: > > - It automatically picks up new directories that aren't considered, > eliminating unpleasant surprises > > - It should eliminate the need for the list to be user-configurable > I was not thinking of this list being user configurable. Lori Alt was thinking of providing support in ZFS to designate these are "special directories" in the root pool. Do you think it needs to be configurable ? -Sanjay
