Lori Alt wrote: > Darren J Moffat wrote: >> As part of the ARC inception review for ZFS crypto we were asked to >> follow up on PSARC/2006/370 which indicates that swap & dump will be >> done using a means other than a ZVOL. >> >> Currently I have the ZFS crypto project allowing for ephemeral keys to >> support using a ZVOL as a swap device. >> >> Since it seems that we won't be swapping on ZVOLS I need to find out >> more how we will be providing swap and dump space in a root pool. >> > The current plan is to provide what we're calling (for lack of a > better term. I'm open to suggestions.) a "pseudo-zvol". It's > preallocated space within the pool, logically concatenated by > a driver to appear like a disk or a slice. It's meant to be a low > overhead way to emulate a slice within a pool. So no COW or > related zfs features are provided, except for the ability to change > its size without having to re-partition a disk. A pseudo-zvol > will support both swap and dump. > > It will also be possible to use a slice for swapping, just as is > done now with ufs roots. But we're hoping that the overhead of > a pseudo-zvol will be low enough that administrators will > take advantage of it to simplify installation (it allows a user > to dedicate an entire disk to a root pool, without having to > carve out part of it for swapping.) > > Eventually, swapping on true zvols might be supported (the > problems with swapping to zvols are considered bugs), but > fixing those bugs are a bigger task than we want to take on > for the zfs-boot project. We decided on pseudo-zvols as > a lower-risk approach for the time being. > >> I suspect that the best answer to encrypted swap is that we do it >> independently of which filesystem/device is being used as the swap >> device - ie do it inside the VM system. >> ' >> > Treat a pseudo-zvol like you would a slice.
So these new zvol-like things don't support snapshots, etc, right? I take it they work by allowing overwriting of the data, correct? Are these a zslice? <aside> For those of us who've been swapping to zvols for some time, can you describe the failure modes? </aside> - Bart -- Bart Smaalders Solaris Kernel Performance [EMAIL PROTECTED] http://blogs.sun.com/barts _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss