I''m building a home server now to replace an Ubuntu box that''s getting old. I''m planning to use OpenSolaris as I want ZFS on the new system. Xen is new to me, but I can see some good uses for it as I have some applications I''d like to run that don''t have Solaris versions that might be difficult to port, and some like TrixBox that are "appliance" type systems that would work in a VM. My biggest question is what to do with the storage. The docs mention that dom0 shouldn''t have user accounts and such, but I would think running the main filesystem in dom0 would be prefered for performance reasons. The main storage array will be 2 6-disk raidz arrays in a ZFS pool. But if I want to share the data out over the LAN with CIFS, NFS, and iSCSI I need users to have accounts in the OS. The only other solution I came up with is running another install of OpenSolaris as a domU and running the file server bits there. But that seems wasteful. Also, is it possible for the guest OS to see the storage array? Something like the shared folders in VirtualBox? I assume I could use NFS and such, but that also seems wasteful. I''d like to expose a path to the guest, so they could see something like /tank/guest/data as a local filesystem, but I could still see the files from other doms and over network connections. I don''t mind if / is a disk image file, but I''d like the primary s torage to be a mountpoint that I can see the files on from outside the guest OS without having to manage file servers and user level permissions in the guest OS. For example, I have considered moving my MythTV backend to this server using a Linux PV guest. Could I share some space out on the main ZFS pool to the guest OS and have those files be visible to another guest and the network shares? How about partitioning RAM? I''ve read to limit the ARC and RAM on dom0, but I''ve also read that ZFS loves RAM. The box currently has a 3-core AMD 2.8Ghz chip with 8GB of ECC RAM. Total available storage in the pool will be about 10TB. -- This message posted from opensolaris.org
I''ve read some more... The kernel file server jobs can''t run in a zone, so that''s out unless I want to use userland NFS/CIFS/iSCSI. I''d like to use the kernel bits as they seem well supported. So I guess I''m running those in dom0. I haven''t found a good way around this. I figure it''s probably not a common use case for Xen. Other than a possible security breach in dom0 granting access to the VMs, is there any reason to really worry about it for my purposes? It looks like all the guest OSes will need to access storage over NFS/CIFS. It''s not ideal, but I think I''m getting a little premature optimization by worrying over performance right now. The data will have to traverse the IP stack, but it''s all local, no actual wire traffic, so it should be reasonably good performance wise. I''ll probably try to have the main OS files live in zvols. As for Linux, some distros are better than others when it comes to PV support. Ubuntu is what I''m using now and it looks like they are right out unless I want to install in hvm mode and build a kernel for PV support. Not a huge deal, so I might still do that. Unsure at this point. -- This message posted from opensolaris.org
Doing CentOS isn''t that bad: http://www.okboot.org/2009/04/linux-centos-domu-guest-in-solaris.html Blake On Sep 8, 2009, at 6:20 PM, Travis Tabbal wrote:> I''ve read some more... > > The kernel file server jobs can''t run in a zone, so that''s out > unless I want to use userland NFS/CIFS/iSCSI. I''d like to use the > kernel bits as they seem well supported. So I guess I''m running > those in dom0. I haven''t found a good way around this. I figure it''s > probably not a common use case for Xen. Other than a possible > security breach in dom0 granting access to the VMs, is there any > reason to really worry about it for my purposes? > > It looks like all the guest OSes will need to access storage over > NFS/CIFS. It''s not ideal, but I think I''m getting a little premature > optimization by worrying over performance right now. The data will > have to traverse the IP stack, but it''s all local, no actual wire > traffic, so it should be reasonably good performance wise. I''ll > probably try to have the main OS files live in zvols. > > As for Linux, some distros are better than others when it comes to > PV support. Ubuntu is what I''m using now and it looks like they are > right out unless I want to install in hvm mode and build a kernel > for PV support. Not a huge deal, so I might still do that. Unsure at > this point. > -- > This message posted from opensolaris.org > _______________________________________________ > xen-discuss mailing list > xen-discuss@opensolaris.org