Arnaud, The virtual machines coming up as if they were on is the least of my worries, my biggest worry is keeping the filesystems of the vms alive i.e. not corrupt. I have all of my virtual machines set up with raw LUNs in physical compatibility mode. This has increased performance but sadly at the cost of vmware snapshots. Is there anything within the virtual machine itself I can do to keep the filesysystem in tact?
In the case of exchange, I have exchange itself on a raw lun in physical compatibility mode, and I have 2 LUNs mounted with the Server 2008 iSCSI initiator for logs and the exchange DB. This is a set up is similar to several other *nix vms I have residing on this SAN. Which I am also worrying about. Any other ideas? Thanks, Greg On Tue, Jan 12, 2010 at 1:11 AM, Arnaud Brand <abr...@esca.fr> wrote: > Your machines won’t come up running, they’ll start up from scratch (like > if you had hit the reset button). > > > > If you want your machines to come up you have to make vmware snapshots, > which capture the state of the running VM (memory, etc..). Typically this is > automated with solutions like VCB (Vmware consolidated backup), but I’ve > just found http://communities.vmware.com/docs/DOC-8760 (not tested though > since we are running ESX and have bought VCB licenses). > > > > Bear in mind that vmware won’t be able to take a consistent snapshot if > some disks in the VM come from VMDK files while some other disks are raw > LUNs (or otherwise mounted directly in the VM, I mean out of control from > esx). You’ll have to restart the machine from scratch in this case and have > a strong potential for discrepancies between VMDK and raw luns. > > On the other hand, I understand that you want Exchange2007 logs and db to > live their live so that when you « revert to snapshot » you don’t loose all > the mail that was sent/delivered in between. > > So this can be a perfectly valid design depending on how you have set it > up. > > > > I don’t think snapshots (be they vmware or zfs) are a good tool for > failover or redundancy here. Basically, if your storage is not accessible > from your esxi hosts, your VMs are toasted and you have to restart them from > scratch. > > Please note, I don’t know about esxi iscsi retry policies specifics. For > ESX we use an SVC cluster (2 node FC cluster), so our ESX hosts can always > access the storage. > > > > You could try to setup an iscsi cluster like this > http://docs.sun.com/app/docs/doc/820-7821/z40000f557a?a=view (look for the > figure at the bottom). You would obtain a mirrored pool where you could > place the vmware zvols. Then you could iscsi-share these zvols. > > Though I’m not sure if/how OpenHA could/would failover if one of your node > fails (I always wanted to play with openHA but don’t have the time nor the > hardware at hand to try it). > > > > This setup of course doesn’t prevent you from doing vmware snapshots and > zfs snapshots, you’ll just achieve some level of fault-tolerance. > > > > Please note I don’t know anything about using NFS with esx/esxi. Maybe > there are setups that are easier to achieve using NFS and provide the same > (or a better) level of fault-tolerance. > > > > Hope this helps, > > Arnaud > > > > *De :* zfs-discuss-boun...@opensolaris.org [mailto: > zfs-discuss-boun...@opensolaris.org] *De la part de* Tim Cook > *Envoyé :* mardi 12 janvier 2010 04:36 > *À :* Greg > *Cc :* zfs-discuss@opensolaris.org > *Objet :* Re: [zfs-discuss] opensolaris-vmware > > > > > > On Mon, Jan 11, 2010 at 6:17 PM, Greg <gregory.dur...@gmail.com> wrote: > > Hello All, > I hope this makes sense, I have two opensolaris machines with a bunch of > hard disks, one acts as a iSCSI SAN, and the other is identical other than > the hard disk configuration. The only thing being served are VMWare esxi raw > disks, which hold either virtual machines or data that the particular > virtual machine uses, I.E. we have exchange 2007 virtualized and through its > iSCSI initiator we are mounting two LUNs one for the database and another > for the Logs, all on different arrays of course. Any how we are then > snapshotting this data across the SAN network to the other box using > snapshot send/recv. In the case the other box fails this box can immediatly > serve all of the iSCSI LUNs. The problem, I don't really know if its a > problem...Is when I snapshot a running vm will it come up alive in esxi or > do I have to accomplish this in a different way. These snapshots will then > be written to tape with bacula. I hope I am posting this in the correct > place. > > Thanks, > Greg > -- > > > What you've got are crash consistent snapshots. The disks are in the same > state they would be in if you pulled the power plug. They may come up just > fine, or they may be in a corrupt state. If you take snapshots frequently > enough, you should have at least one good snapshot. Your other option is > scripting. You can build custom scripts to leverage the VSS providers in > Windows... but it won't be easy. > > Any reason in particular you're using iSCSI? I've found NFS to be much > more simple to manage, and performance to be equivalent if not better (in > large clusters). > > > -- > --Tim >
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