Xencenter 5.5 wow

[Steven_Cleaver]

We have just had Visualisation setup at are our establishment and are using Xencenter 5.5 wow.

 

Live Migration.

Snapshotting.

 

And so much more

 

Wow again.

[cookie_monster]

I'm pretty impressed with it myself the only issue that i've found so far is that it doesn't support jumbo frames (as far as I can tell) but it seems fast enough without. Once you get your head around it it's a breeze to setup and manage. It also can't handle card bonds of more than 2 nics. Overall though i'm impressed especially for the price

 

Must have a play with the snapshotting

Edited August 6, 2009 by cookie_monster

[Soulfish]

I'm pretty impressed with it myself the only issue that i've found so far is that it doesn't support jumbo frames (as far as I can tell) but it seems fast enough wothout. Once you get your head around it it's a breeze to setup and manage. It also can't handle card bonds of more than 2 nics. Overall though i'm impressed especially for the price

 

Must have a play with the snapshotting

 

You can fudge jumbo frames if you make the PIF unmanaged and set it up manually. There's also a way of changing the MTU using one of the xen server commands for managed PIFs, but from what I've read it tends to break Xenserver

 

I only know this cause I've just spent the last two days setting up a 3-way bond for our storage network, which is now working brilliantly

[cookie_monster]

I'd read a few ways on the forums but most had the dreaded 'unsuported by Citrix' next to them so I avoided it.

What's involved in setting up the PIF as unmanaged?

[Soulfish]

Multiway bonding was surprisingly simple to setup, and if it goes wrong you can always run a xe pif-scan command to have Xenserver redetect all the PIFs and rewrite all the config files

[cookie_monster]

Fortunately i've only got two spare Nics on each box so the two card bonds I have will do just fine for now but i'll look into it for future reference.

[FragglePete]

Spent the last few days with a CSE Engineer implementing XenServer 5.5.

 

Now have 4 virtual servers running on a new compaq server, one for shares, one as a secondary DC & DNS, One for Printers and the other I will use for things like WSUS and AV.

 

Seems to work really well and I think its a good way of dabbling into Virtualisation; I'm already planning proper SAN setup for next year. Will see how this year goes along with budgets.

 

Not played with the Xen Console too much yet, but from what I was shown I am mightly impressed.

 

Pete

[cookie_monster]

As I say I haven't played with the snapshots yet, how much space do they use is it the same as the VM size or just changes since the last snapshot?

 

Cheers.

[Steven_Cleaver]

I haven't played with it that much but I have tried live snapshotting so without stopping the Server it creates a small file that holds the settings about 8Mb but it also creates a virtual disk for that snapshot the same size as the Virtual disk on the snap shotted server.

 

You can then create a new VM from this snap shot so again this would take up the size of the original server (make sure if you do it live you copy in the Mac address from original VM) so for a short time you would require at least three times the space of the original server. You can then delete the original snap shot and the Virtual drive it created.

 

This all take a few of minutes at most to do, so is really impressive.

 

I am not to sure I would live snap shotting on my DC's with AD running or my SIM's server but have tried this on the print server and application server shutdown the old server and restarted the new VM I created from the snap shot everything worked fine really impressive.

 

I am not to sure if this is the same if you stop the server first, but I'll give it a go over the weekend.

[Ric_]

I've been using XenServer since 4.1 and 5.5 is brilliant. I've used it since it was released.

 

I configured Workload Balancing yesterday As a hint, don't use an underscore in the username

[Soulfish]

I've been using XenServer since 4.1 and 5.5 is brilliant. I've used it since it was released.

 

I configured Workload Balancing yesterday As a hint, don't use an underscore in the username

 

Looking at setting up WLB in the next couple of weeks - thanks for the tip . One quick question I've been meaning to ask - what Linux distributions are you all using for your VMs?

[cookie_monster]

I have bonded two NICs on a xenserver and they're working fine but i'm a bit concerned that i've not got the switch ports configured correctly. I have a feeling that the ports on the switch should be in a static trunk to prevent mac flapping.

 

How do you all have your switches setup for your Xen NIC bonds?

[Ric_]

@Soulfish: I'm a Debian man (although I also have 1 CentOS VM)

 

@cookie_monster: I seem to remember that you just switch on LACP on the ports and it sorts it all out itself

[cookie_monster]

I setup LACP on the trunk to the SAN and that works well but the Xen bonds wouldn't work when setup as LACP (maybe the Xen side doesn't support LACP). I'll try a static trunk next time I get some downtime just wondering if anyone already has this setup, I might also try LACP again to rule out me having it set wrong last time as i'm more familiar with the XEN and the SAN now.

 

Cheers.

[Soulfish]

Thanks Ric_ - I've actually ended up using CentOS for my new Linux VMs on Xen. I'm usually a debian man myself, but after playing with the XenServer CentOS for the past two weeks and since it seemed to be better supported I opted for that

 

@cookie_monster the default bonding mode is bonding-slb (mode 7) which I've struggled to find much on. What I have read (most of it is on the Citrix Xen Forums!) is that it doesn't require any switch support. According to XenServer Documentation traffic will only be going out over a single interface at a time so hopefully no problems will occur!

 

If you want to use another bonding mode (like LACP/802.3ad) then it is possible to modify the XenServer network scripts to use this, but it is an unsupported configuration .

Edited August 17, 2009 by Soulfish
too many modes!

[AJT1]

Don't know whether this is any use to anyone. Might have already been posted.

[cookie_monster]

@cookie_monster the default bonding mode is bonding-slb (mode 7) which I've struggled to find much on. What I have read (most of it is on the Citrix Xen Forums!) is that it doesn't require any switch support. According to XenServer Documentation traffic will only be going out over a single interface at a time so hopefully no problems will occur!

 

 

Hmm I wonder how they prevent mac flapping, I suppose if it only sends on one link at a time then it could be avoided but it still must confuse the switch. If traffic is only going out on one link at a time then the bond must be about redundancy rather than throughput.

[Ric_]

@cookie_monster: I've just double-checked and I was telling you lies. The LACP is the SAN stuff, the XenServer boxes have no special config.

 

I think that the reason it works, is because each VM can only use one NIC at a time. XenServer presents the virtual NIC's MAC to the network and all is well. The balancing of the load across NICs is redone every few seconds.

[cookie_monster]

Ok cheers looks like i'm all set to go then