On Mon, Feb 04, 2013 at 08:13:20PM +0400, Alexander Gordeev wrote: > Hi! > > I'd like to develop libvirt integration with Parallels Cloud > Storage (Pstorage) which is a new distributed file system from > Parallels designed specifically for storing VM images: > http://www.parallels.com/products/pcs/cloud-storage/ Yay, yet another filesystem :-( Everyone seems to think they need to write their own custom network/cluster/cloud FUSE filesystem these days. > It's not a POSIX FS but there is a FUSE client for it that can be > used to access and manipulate images. It's quite high speed but only > when used with O_DIRECT + aio. I tried to setup several KVMs on top of > a Pstorage mount using virt-manager. It worked good, but I had to: > 1. tune cache and IO settings for every disk > 2. disable space allocation by libvirt because it is using sync IO and > is therefore slow > > I tried to find ways to solve the first issue and IMHO this can be > done by adding a way to specify per-pool defaults for cache and IO > settings. I didn't find any way for this in the current code and UI. > I'd like to add a new storage backend also that will be a 'dir' backend > with extra ability to manage Pstorage mount points and UI integration. > I'd like to merge my work to the main tree when it's finished if > possible. I don't think that putting cache/IO defaults in the XML is really appropriate. There are too many different scenarios which want different settings to be able to clearly identify one set of perfect settings. I see this as primarily a documentation problem. Someone needs to write something describing the diferrent settings for each storage pool & what the pros/cons are for each. Downstream app developers can then make decisions about suitable defaults for their use cases Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list