Hi I am no expert, but I have used several virtualisation environments, and I am always in favour of passing iSCSI straight through to the VM. It creates a much more portable system, often able to be booted on a different virtualisation environment, or even on a dedicated server, if you choose at a later date (sometimes takes a little work, but it is easier than the alternatives).
For ZFS, I would suggest this is even more useful. One could, theoretically, export a pool from one VM, then easily import it on another, or on a random machine. If you are looking for a solution for this, I would suggest looking at gPXE (http://etherboot.org/wiki/start). It allows booting from iSCSI fairly easily, and they have a guide for booting opensolaris. Just my 2p :) Regards Karl > -----Original Message----- > From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Edward Ned Harvey > Sent: 14 February 2011 23:26 > To: 'Mark Creamer'; zfs-discuss@opensolaris.org > Subject: Re: [zfs-discuss] ZFS and Virtual Disks > > > From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > > boun...@opensolaris.org] On Behalf Of Mark Creamer > > > > 1. Should I create individual iSCSI LUNs and present those to the VMware > > ESXi host as iSCSI storage, and then create virtual disks from there on > each > > Solaris VM? > > > > - or - > > > > 2. Should I (assuming this is possible), let the Solaris VM mount the > iSCSI > > LUNs directly (that is, NOT show them as VMware storage but let the VM > > connect to the iSCSI across the network.) ? > > If you do #1 you'll have a layer of vmware in between your guest machine > and > the storage. This will add a little overhead and possibly reduce > performance slightly. > > If you do #2 you won't have access to snapshot features in vmware. > Personally I would recommend using #2 and rely on ZFS snapshots instead of > vmware snapshots. But maybe you have a good reason for using vmware > snapshots... I don't want to make assumptions. > > > > Part of the issue is I have no idea if having a hardware RAID 5 or 6 > disk > set will > > create a problem if I then create a bunch of virtual disks and then use > ZFS to > > create RAIDZ for the VM to use. Seems like that might be asking for > trouble. > > Where is there any hardware raid5 or raid6 in this system? Whenever > possible, you want to allow ZFS to manage the raid... configure the > hardware to just pass-thru single disk jbod to the guest... Because when > ZFS detects disk errors, if ZFS has the redundancy, it can correct them. > But if there are disk problems on the hardware raid, the hardware raid > will > never know about it and it will never be correctable except by luck. > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
