The complete Q&A from the Citrix XEN Masterclass webinar
A couple of weeks back I attended the excellent Citrix XEN Masterclass webinar. There were a LOT of questions fired on all kinds of XEN topics.
Because there were so many great questions during the webinar I didn’t want that information to be lost, so in this post I’m providing all the Q&A stuff from that session. If you have a question about XEN Server, chances are that the answer is in here.
DISCLAIMER:
These question were all asked in a “ask me over a beer” scenario so in other words: The answers do not represent the opinion of Citrix in any way shape or form.If this post helped you out, help me out keeping this site alive and visit some of my sponsors on the left or right.. Thanks..!
Q: XenServer v XenApp v XenDesktop – when to use these?
A: XenServer is the best fit to run XenApp and XenDesktop workloads on.
Q: Is there an option for scheduled snapshots?
A: Yes, Protection & Recovery is the feature for scheduling and archiving virtual machines
Q: How does one replicate a LUN to a DR site? Is it built into XenServer 5.6 or is it only 3rd party tools?
A: You have to use StorageLink Site Recovery for this to replicate virtual machines to a second datacenter. There is a failover and a failback option what makes this a unique solution.
Q: what are the benefits of AD integration? What will AD integration give me?
A: * You don’t have to deploy your XenServers root password to an administrator which should just administer some virtual machines. Users can use their known AD credentials to log on to XenCenter
Q: Is the Feature Pack1 for Enterprise Edition also free?
A: FP1 is a XenServer version for all XenServer editions. So FP1 is for free, advanced, enterprise and platinum and you still just have to pay for adv. up
Q: Is there any chance to see one day coming live migration from AMD to Intel Arch?
A: This is very hard to implement as of the different architectures and not in the actual product.
Q: I have been told (by Citrix) that XenDesktop is best to be virtualized on Hyperv.
A: That is not right in this way. The VRC study shows different hypervisors for different workloads. see www.virtualrealitycheck.net. BTW: Our goal is still to deliver the best virtualization platform for XenDesktop and XenApp
Q: would be wonderful to see XenCenter running on MacOs …
A: Not planned at the moment.
Q: How does the HCL of XenServer compare to ESXi. Is it comparable..?
A: *Not really. Everything on there is certified and supported. We have mostly more on our HCL because we use standard drivers and don’t have to implement our own.
Also customers can put their hardware on the hcl using the self certification kit
Q: Can you choose which VMs a user has access to when using AD, or is it all or nothing?
A: * You can give users access to specific virtual machines with our Web Self Service Appliance. a user can access just his virtual machines using his AD credentials
Q: Any timetable for USB and PCI passhru?
A: No. But for USB best practice is to us a ethernet remote USB box. This will allow you live migration even if a USB device is connected.
Q: Is Dom0 the system you connect to using ssh and run xe commands on?
A: Yes. But you have many possibilities over API, remote scripting, …
Q: When will XenServer have support for jumbo frames?
A: *Jumbo frame support is already there with the virtual switch. It comes with the FP1
Q: Can you use xenserver on usb drive
A: There are several options to put it on a USB drive but this is officially not supported. But for testing and playing around it should be ok…
Q: Does XenServer/XenCenter have the distributed Virtual Switch like VMware?
A: Yes, it comes with the Feature Pack 1. The Switch is integrated in the free edition and the controller for administering multiple virtual switches as a part of the advanced edition.
Q: Is the Protection & Recovery feature included in 5.5 or on 5.6?
A: It is in 5.6 FP1, not in 5.6 or 5.5
Q: Is Linux version of XenCenter planned?
A: No, at the moment not. But there is a free open source implementation for Linux on http://www.openxenmanager.com/
Q: why xenapp better on xenserver, is ica passed through the hypervisor?
A: No. It is because of handling memory in a different way. There is a very detailed blog article on the community on that
Q: Will converting vm to template always be a one way process?
A: Yes, therefore best practice is to make a copy of the vm and convert the copy to a template
Q: Is there any way to do a block level backup of a SR using XenCenter?
A: No, at the moment not
Q: Is it possible to build Xen cluster with two different intel-based server?
A: Yes, you can !!! There is a feature called heterogeneous pools to put different intel CPUs (or AMD CPUs) together in a pool. But you cannot mix Intel and AMD
Q: can you cluster with the free version of xenserver
A: yes you can build a cluster with the free version with shared storage and live migration.
Q: What about the rumours that Citrix is going to stop development on XenServer? (i don’t hope so)
A: Nothing on it! The power of XenServer will go on for server virtualisation and Cloud …
Q: Can XenServer 5.6 run a VDI environment for test purposes?
A: Sure…
Q: would be nice to see linux admin tools, XenCenter
A: Not planned at the moment . But take a look at http://www.openxenmanager.com/
Q: Is it possible to build a Pool between Intel Xeon 5140 and Intel Xeon 5150 CPUs ?
A: Should be possible. If both CPUs have the FlexMigration feature from Intel it works fine with the advanced editon up
Q: I haven’t seen Ubuntu listed as a OS in the install list – is it likely to be added at some point?
A: It is at the moment experimental but planned to be fully supported in a next version
Q: How long does it take to convert a vmware machine to xenserver?
A: Depends on the size of the virtual machine . There is not a real fix answer to this. Sorry…
Q: what is the equivleant citrix has that vmware has a virtual centre
A: * There is no equivalent because we didn’t need an additional management server. Just install XenCenter on a Windows desktoip system and manage your resource pool
Q: With the memory ballooning with xenserver 5.6 does it use a vswap file somwhere within storage?
A: No. We use memory balloning. No swapping of memory pages!
Q: What are recommended backup methods of VMs and associated metadata?
A: long answer what will blast this session. You have some basic options in XenServer, Metadata export, protection & recovery, export/import. If you would like to do more powerfull backup you have to choose a 3party solution…
Q: Can i use the option “GPU pass-through (GPU-Virtualization)” in the free version?
A: Should be possible…
Q: is there a xenserver maxims document available?
A: unfortunately not. All maximums are described in the reference guide…
Q: Using AD access does that require full lic?
A: No, AD integration is in the free version. If you want to user role based administration you have to upgrade to enterprise…
Q: Will there be an option in the future to migrate hosts in and out of resource pools WITHOUT losing the local storage (VM’s running on local storage)?
A: Not heard about such a function
Q: Is XenDesktop basic package (one for up to 10 users – downloadable for demo/test purposes) free for use even for production purposes as long as you limit it to 10 users?
A: This is a XD question and don’t hang me if I am not 100% right As I know officially it is not supported in production.
Q: Is it possible to create complex network topology with xenserver? I.E. one firewall virtual machine with two network adapters one bridged to physical adapter, the other fully virtual and another machine connected to the firewall purely through the virtual link?
A: Yes you can build such a solution with a XenServer environment…
Q: Role based access – the limitations of the free version were not clear
A: RBA is in the Enterprise edition. nothing in the free one. In the free there is the AD integration and a limited (25 VMs) Web access to VMs …
Q: is powershell of any use?
A: * Yes, we have a Powershell plugin so that you can do remote administration using powershell
Q: Are all domain users default admin (root)?
A: If you use the free edition: yes. If you use RBA in the enterprise: No
Q: Is there a tool available similar to VMWare convertor in order to migrate single or multiple Xen VM’s between seperate Xen Pools, without the need to manually export to file service and import to new Pool 2 1 at a time?
A: We have a tool called XeNCenvert but this is for migartion what is not really the same than export/import. But I think VMW converter is also just for migration…
Q: what prevents a user to login still with the ‘normal ‘ tool versus the web-based-access?
A: * You can assign the user “no” role in XenCenter. So he has the possibility to access his VMs in the Web interface buit no access to the XenCenter
Q: License fee’s are per year and server?
A: You can use the server until it dies. Included is one year free subscription to upgrade all time to the latest version.
Q: Xenserver looks very similar to ESXi, what advantages does it offer over and above what VMWare can do?
A: Its along to VMware the only enterprise ready hypervisor solution. On the other hand it is much more simpler, easier to use and learn and has a very big price difference to the expensive VMW
Q: Is the Citrix License Server Virtual Appliance for XenServer in .ovf format and can you use it for other Citrix products like XenApp/Xendesktop?
A: It is in XVA format and officially it is only supported for XenServer at the moment…
Q: XenCenter installs a SQL express server to maintain the database or..
A: * No, XenCenter is just a simple frontend which you install on you local desktop. No database is required…
Q: any chance to put 2 boxes with different hardware in the same cluster? Both using XenServer 5.6
A: yes, using the heterogenous pool feature you can put together server with different CPUs
Q: Can I Update a Xenserver 5.0 to 5.6 directly?
A: No, Upgrades should be from version to version. 5.0 > 5.5 U3 > …
Q: Can we use the existing XenApp on top of new XenServer? Currently it’s running on top of ESX.
A: Sure. Just migrate the workloads to XenServer and enjoy the performance.
Q: I have two iSCSI storage arrays. Using XenServer only, can I create a Storage Repository that abstracts the two separate storage arrays, presenting them as a single SR?
A: No, in a normal iSCSI way a single LUN is representing a SR. If you arrays have the possibility to represent two differnt LUNS as a virtual one then it should be possible
Q: Does the fast clone of a VM take a full copy or is it more like a linked clone re vmware?
A: It works with different disks liek in the snapshot way. When creating a fast clone there is created a diff disk which is hosting all the differences…
Q: can you cluster with the free version of xenserver YES or NO
A: YES
Q: How long will ik take to convert a hyperV VM to XenServer?
A: Hard to answer. Depends on the size of the Hyper-V virtual machine…
Q: do you have to manually mask the CPU features or is it automatic?
A: * You can do both ways. Automatically using XenCenter or manually using the command line
Q: Since what version can you build heterogeneous pools? I was unable to using XenServer 5.0?
A: * Since Version 5.6 it is possible
Q: Is the heterogenous pools available in the free version?
A: No, Advanced up…
Q: hterogenous pool is enterprise function, or is it in the enterprise version?
A: It is enterprise in 5.6 but moved to advanced edition in 5.6 FP1
Q: Can you snapshot from XenCenter like shown in the demo when using StorageLink?
A: * Yes. snapshot is always from XenCenter or the CLI. XenServer knows what to do for the attached Storage Array (StorgeLink, iSCSI, FC, NF, …)
Q: Can you mix AMD & Intel hosts?
A: No, that is not possible at the moment…
Q: when will the next version of xenserver be released?
A: Q2 2011 is planned
Q: gives a Fault tollerance support in the free version?
A: Yes with Marathon it is possible also with the free version
Q: I’m sure the guys metioned this but just want to make sure. With shared storage can you live migrate a VM from host to another on the FREE version?
A: Yes, it is possible in the free version…
Q: Multi-GPU Passthrough is a Tech Preview feature of XenServer 5.6. When is out for “real”
A: Planned for the next version…
Q: 5.6FP1 doesn’t seem to have much on it’s HCL yet – eg no dell MD3000i, and only a handful of broadcom and Intel NICs – whats the sort of timescale to expand this?
A: It is a question of what has been certified at the moment. Every user can self certify his hardware and put it on the HCL. Jus run the self cert kit from http://www.citrix.com/ready/hcl
Q: what difference between Full CopyVM and Fast CopyVM ?
A: Full copy is a 1:1 copy of the whole virtual disk. Fast clone is a diff disk copy what gets more faster…
Q: Platinum Edition, is it 5000$ for a year?
A: This is list price for the license and one year subscription. After one year you can buy subscription for less than 5000$ but I don’t know the price at the moment..
Q: Is it possible to use the existing XenApp running on top ESX, and copied it to XenServer?
A: No copy but you have to migrate the virtual machine. We have a experimental VMDK import wizard which works normally very fine…
Q: Are there any training classes online for learning about Xenserver? Free or paid?
A: Yes, please take a look at http://www.citrixtraining.com/
Q: when upgrading to FP1 should you move all your VMs from local storage if implementing intellicache?
A: You can only select thin provisining for local storage when you do a fresh install of XenServer. During upgrade there is no possibility. So you have to upgrade,
backup you VMs. destroy the old local SR, create a new one (ext3) and activate intelli cache for the local SR…
Q: Ist es möglich unter 5.6 FP1 das Ziel des Snapshots zu ändern? Den snapshot auf ein anderes Storage zu legen?
A: Nein, aktuell nicht.
Q: i have 2 boxes with Xen Free v5.6 and can’t put it in the same pool. I always receive the error saying that the hardware is not compatible. Any word about it?
A: This is not possible in the free version. with 5.6 you need enterprise editon, With 5.6 FP1 you need advanced minimum..
Q: is there any server p2v consolidation tools available from citrix?
A: Yes. It is called XenConvert and it is free..
Q: To do XenMotion, is the only pre-requisite to have a shared storage area? eg NFS, iSCSI
A: Yes, shared storage is a requirement
Q: It’s possible to enlarge a storage (SAN storage) on line? Without suspend or shutdown host or migrate virtual machine.
A: no, not possible. The only supported ways are described in the refernce doc.
Q: How about the upgrade from 5.6 to 5.6 FP1 if you have a Xenserver up and runnig? Does it upgrade or does it reinstall the Xenserver? I´m thinking of the
configureation of SR and so on.
A: * It is keeping all the existing informations when upgrading to a new version…
Q: Is there an option for scheduled VM Export?
A: Protection & Recovery in 5.6 FP1 can do this..
Q: Any timetable support for parallel port, serial port?
serial port ist not problem through TCP/IP,but parallel port nothing found.
A: No…
Q: When will it be possible to passthru PCI devices such as SAN HBAs to VM? I need to present EVA LUN to VM.
A: What you can do is to use StorageLink which can map LUNS directly into a virtual machine
Q: Can I carry out an in-place upgrade from XenServer 5.0 to XenServer 5.6 FP1?
A: Yes, this is possible
Q: 5.5 and 5.6 in one pool?
A: No
Q: so for platinum with 10 servers in 1 pool, you have to pay 50000$???
A: Yes. But if you compare to other virtualisation vendors with the same functionality with XenServer you can save a lot of money…
Q: When will the Free Feature Pack 1 upgrade be available?
A: Is available since december 2010…
Q: Where does XenCenter hold its config for HA and DRS for example??
A: XenCenter does not hold any information for the XenServer pool. Everything is located on the pool database hosted on the XenServer itself
Q: What is v6 licensing?
A: Citrix licensing modell which is standard for all Citrix products
Q: Is intellicache suitable for xenapp? you only mention xendesktop.
A: It is mainly focused on XenDesktop…
Q: when using HA on lets say 4 xenservers and the master fails and HA changes the master but wouldn’t you have to tell other xenservers that they have a new pool master
A: No, works out of the box. This is a HA feature. Also if you connect with XenCenter to the old master which is no longer available you will be redirected to the new one…
Q: is the maximum number of vnics per vm still pegged at 7 vnics?.. or can you add more vith fp1?
A: 7 is still the supported limit..
Q: How do you get the web based management? The beta programme is currently closed
A: Just download it from www.mycitrix.com. It is free for up to 25 VMs…
Q: We have “XenServer for XenDesktop” licenses loaded on our XenServers. How does this version compare to the Enterprise edition?
A: It is a full enterprise edition
Q: Can you convert a current pool to a heterogenous pool?
A: Sure. Just add a new server and CPU masking will be done by XenCenter…
Q: How do you handle the long VDI chains reluts with many snapshots?
A: Supported are up to 32 Snapshots and all of the VDI chaining is handeld by the XenServer under the hood…
Q: Is it possible to select the Storage where Snapshots should be stored ?
A: No, at the moment not..
Q: Are the “scheduled snapshots” available on free version?
A: no, you have to script it…
Q: in my local or sam store when make one snapshot and delete the space after this do not show me corretly , why ?
A: This is solved with XS 5.6 FP1
Q: do the snapshots work like in VMware lock the original disk file into read mode and add a redo file
A: it’s nearly the same. Lee is describing it at the moment. otherwise there is a whitepaper on our support forum describing this in detail
Q: Does local storage support thin provisioning on disks as shared storage does?
A: Yes, but you have to choose ext3 as a local storage and not LVM.
Q: what;s happaning with dvs at XS pool if DVS controller is fail?
A: Network and switchin is still working. The ACLs will not be applied an everything will fail open…
Q: Where can I download the Xenserver Web Self Service Portal?
A: www.mycitrix.com
Q: When will you support to take quiesced snapshots of 2008 R2?
A: It is supported…
Q: Any timetable support linux software raid ?
A: No..
Q: any plans to provide distributed vswitch functionality … i.e. as currently available in vmware 4.1
A: It is already there with 5.6 FP1
Q: Does the memory oversubscribe work on XP
A: Yes, on every operating system where the Xentools are installed…
Q: can I do xenmigration with virtual switches on the free version?
A: Yes…
Q: Should we use NFS or LVM for VDI?
A: I personally will recommend NFS as it is thin provisioned and works with MCS and intellicache…
Q: Can we use a NAS virtual machine in one of our XenServers for our pools or we must use a dedicated machine just for that?
A: Sure, thats possible…
Q: Is any version of XS available with a Plat XA licenses?
A: No, all XA licenses only include the free XenServer version. You have to trade up to XenDesktop to use XenServer Enterprise
Q: Any news on the StorageLink – Equallogic API?
A: No…
Q: are netapp and equallogic the only storage systems available for storagelink?
A: No, there is abroad storage integration from EMC, Datacore, Hitatchi, Nexenta, OS Nexus, … Please look at the HCL
Q: Is the 2TB VM Vdisk storage limit going to be increased soon?
A: not planned
Q: Did Lee say XenDesktop includes licenses for XenServer Enterprise or XenServer Free?
A: XenServer Enterprise is included in XD
Q: Any other reasons for a new installation beside intellicache from 5.6 to 5.6 FP1 than a upgrade?
A: No, we simply create a new local SR and activate it for intelli cache. You can imagine that it is hard and complex to migrade a existing LVHD to ext3
Q: can you use powershell
A: Yes, there is a powershell plugin for XenServer available. just google it and you find it on the first results..
Q: Xen Free 5.6, Intel Xeon and Intel Core Duo in one pool ?
A: No… Heterogenous pools start in advanced…
Q: Can I live migrate Windows 2000 Server in 5.6 Fp 1
A: * should work but just with old XenTools because Windows 2000 support is dropped in XenServer 5.6 FP1
Q: Does, live migration also work for XenApp and it’s user sessions?
A: Yes it works also for the user sessions
Q: I’ve just purchased a brand new server systems can i just install xenServer first before installing any OS?
A: yes, if you have the right server system you need a processor that supports intel-VT or AMD-V
Q: How do we upgrade a single server enviroment from 5.6 to 5.6 FP1?
A: Just use the install CD. but you have to plan a downtime
Q: are netapp and equallogic the only storage systems available for storagelink gateway?
A: * no . Please take a look at the StoragLink HCL. There are a lot of more Arrays we support
Q: 2008 R2 Sp1 is not supported on XenServer 5.6, must we upgrade all XenServers 5.6 vertions to 5.6 fr1 to be sure that we can upgrade to 2008 R2 SP1?
A: yes…
Q: XenServer free version, is always free for the lifetime?
A: yes…
Q: What is the download link for Web Self Service?
A: www.mycitrix.com go to downloads and select XenServer
Q: Hi, is i possible to convert a Windows 2003/2008 server to Xen VM without having a running XenServer? The idea is to install the XenServer on the same machine…
A: * Yes you can migrate the machine to OVF or VHD format and after this import it to XenServer
Q: Is there a way to remove a server from a pool when the option is greyed out (due to a server with the wrong IP being in the pool)?
A: You can just power it down and then use the forget option to remove it from the pool…
Q: I’ve just purchased a brand new server systems can i just install xenServer first before installing any OS?
A: yes, you can…
Q: Is there a way to export a template from a pool and import it to another pool?
A: Yes, sure, just export the template and import it to the new pool
Q: Can SCSI controllers be supported for tape based backups
A: no, at the moment not..
Q: Can you mix free version with other version?
A: no, that is not possible…
Q: starting xenserver from flash like vmware is it possible and approved/supported ?
A: possible it is but not supported…
Q: how is the HA policy replicated between the xen hosts?. What happen if the master server goes down?
A: * all pool informations are replicated in real time in the whole pool. If a master goes down HA automatically nominates a new master. If HA is not active you have to do this manually on the command line…
Q: Someone asked about USB and PCI Passthrough and you answered that the best practice for USB is an ethernet USB box – is PCI Passthrough working right now? We have a Sangoma PCI card we’d like to use in a VM…
A: Should work but at the moment not supported…
Q: Is it possible to run VM’s on NFS mounted SR’s with no performance concerns?
A: Hard to answer because performance hardly depends on the storage array. So yes, you can run them from NFS and many customers already doing this but performance depend on the storage array
Q:Is there a “best practice” dor converting a Windows Small Business Server (Physical to virtual)?
A: no, no best practice but I have written a blog artice to run SBS on XenServer
Q: : is the maximum number of vnics per vm still pegged at 7 vnics?.. or can you add more vith fp1?
A: no, 7 is still the supported number…
Q: Can you demo any kind of performance measurements like disk i/o
A: There is a CTX article discribing this: http://support.citrix.com/article/CTX124157
Q: Can you recommend a 3rd party backup solution?
A: PHD virtual !
Q: how do i create a virtual switch on the free edition?
A: You have to activate it on the commandline. Please see the doc for the detailed command
Q: What do I have to ceep in mind when installing XenServer without an AD just given?
A: nothing special. You have a root account to administer your environment and if someone should have access to XenCenter he needs the root accound and then can do all administrative tasks…
TAGS: Citrix, XEN, Masterclass, Q&A