Virtual

Most of the time your HA issues are going to be DNS related. So ensure that your vcenter can ping all your hosts by FQDN without issue.  In some cases though a stubborn server may not want to play the game even when everything is configured properly.

This method is considered a “last effort” as you’ll need to run some CLI commands on the ESX box. But i have found it useful in a few situations.

I’ve had this issue in vSphere where a machine appears to be powered on (both to vCenter and ESXi) but is not actually running.

I get this when trying to power off the virtual machine “…cannot be performed in the current state (powered on)” - which is somewhat strange.

So i have resorted to CLI to check the machines status and then force it off.

This page at vmware explains the various methods (as you progress through them they get more extreme): http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1014165

This bug has hit me. Looks like users with roles like vm user / power user cannot send “ctrl-alt-del” via the console even though they have the correct permissions. Our users cannot use ctrl-alt-ins as they are connected via RDP to a machine that has the console installed.

Found this : http://communities.vmware.com/thread/220683;jsessionid=480C8A2C9B9EACA9FF2BB4E1BECA2D53?start=15&tstart=0

Looks like its a known bug and will be fixed in the upcoming VC4.0 update 1 sometime Q3 2009 :(

I’ve had some problems since my upgrade to virtualbox 2.2.0 on OpenSolaris. After some time all of my linux boxes seem to just die. The virtual machine just stops responding. Strangely there was no problem with my windows vms after the update.

From what i can tell it looks like the upgrade turned off “IO APIC” - this is the bit that seemed to cause the problem. Re-enabling this on all of my linux boxes seems to have fixed the problem. I’ll continue testing for another week and update this post if any problems re-occur.

One of the best articles i have found on this subject is here : http://blog.scottlowe.org/2008/07/16/understanding-nic-utilization-in-vmware-esx/

There is some additional information here on setting up an etherchannel on the cisco side : http://blog.scottlowe.org/2006/12/04/esx-server-nic-teaming-and-vlan-trunking/

This can be handy if you need a single VM to use both physical nics in a load-balanced manner - both outbound and inbound. Of course its not really that simple though. This will really only add a benefit if the VM is communicating to multiple destinations (using ip hash - a single destination from a single VM with one IP will always be limited to the same physical nic).

Since im using ZFS as storage via NFS for my some of my vmware environments i need to ensure that latency on my disk is reduced where ever possible.

There is alot of talk about ZFS compression being “faster” than a non-compressed pool due to less physical data being pulled off the drives. This of course depends on the system powering ZFS, but i wanted to run some tests specifically on latency. Throughput is fine in some situations, but latency is a killer when it comes to lots of small reads and writes (in the case of hosting virtual machines)

I’ve had a couple of installation issues with ESX4

One was particularly strange, the install process would freeze every now and again until i pressed a key on the keyboard. This was related to AMD’s power saving C1 mode - disable this in the bios to fix this problem.

Secondly it was a problem with my nic. Essentially i didn’t have card that was supported (realtek). After inserting a intel card all was well. This fires up a ambiguous error and cans the whole install. (lvmdriver error)

I had decided to try out Citrix Xen Server at home since i work a lot with vmware during my working week and felt like a change. It all seemed well… That is until i had to deal with snapshots. I suppose i have taken for granted almost all other virtual host software that provides a simple “revert to snapshot” option. From what i can tell this is totally absent from Citrix XenServer 5.5.

To share your zfs pool via NFS (that works with Citrix Xen / ESX) to a host called “esxhost”;

zfs set sharenfs=rw,nosuid,root=esxhost tank/nfs

Note : You MUST have a resolvable name from the opensolaris box. i.e. you should be able to ping it. I have tried with ip’s only and it will fail. I have edited the /etc/hosts file to include the following line for my config;

# Copyright 2007 Sun Microsystems, Inc. All rights reserved. # Use is subject to license terms. # # ident “%Z%%M% %I% %E% SMI” # # Internet host table # 192.168.9.120 esxhost

This is something i do in the lab so all of my vm’s are able to access iso’s etc (very handy for quick builds). Quite handy doing it through windows since its easiey enough to setup a windows network share to the same location and update various files via that.

This site has some good clear instructions : http://vmetc.com/2008/02/19/create-a-nfs-share-for-vm-iso-files-with-windows-2003-server-r2/

1. On the Windows 2003 Server make sure “Microsoft Services for NFS” in installed. If not you need to add it under Add/Remove Programs, Windows Components, Other Network File and Print Services
2. Next go to folder you want to share and right-click on it and select Properties
3. Click on the NFS Sharing tab and select “Share this Folder”
4. Enter a Share Name, check “Anonymous Access”
5. In VirtualCenter, select your ESX server and click the “Configuration” tab and then select “Storage”
6. Click on “Add Storage” and select “Network File System” as the storage type
7. Enter the Windows Server name, the folder (share) name and a descriptive Datastore Name
8. Done. Now you can map CD iso’s to your various vm’s.

 

I’ve had this with certain kernels (2009.06) on opensolaris. Seems there is some incompatibility between some kernels and the opensolaris virtualbox network emulation. This only seems to effect linux virtual guests.

When you try to ping an address you get something like this…

[root@VA-DHCPWEB ~]# ping 192.168.9.15 PING 192.168.9.15 (192.168.9.15) 56(84) bytes of data. 64 bytes from 192.168.9.15: icmp_seq=1 ttl=128 time=1.85 ms 64 bytes from 192.168.9.15: icmp_seq=1 ttl=127 time=1.88 ms (DUP!)

ESXi 4 has been released under a new infrastructure name “VMware vSphere 4.0”

Some of my favorite features so far;

• Host Profiles - Finally you can just apply a host profile to a newly created vmhost. Previously this was a pain to setup all the storage / vlan configuration on each host.
• Thin Provisioning - Awesome, now disk can be allocated dynamically allocated as needed. Just like it is on vmware virtual server. Perfect for a lab environment where performance is not needed.

http://vmware.com/

I’ve been dabbling with virtual box up until this point. But have decided to take it to the next step by using xvm to run my virtual machines. I have taken a guide from BDerzhavets at this site : http://bderzhavets.blogspot.com/2008/12/xvm-on-opensolaris-2008.html

First step is to open package manager and find the “vitalization” grouping. Install everything in this group. You’ll probably find some packages are already installed.

Next you’ll need to add the xvm kernel to the grub startup menu (menu.1st). This bit is a bit of blind faith from my perspective - its a shame that the xvm kernel package doesn’t add itself to grub? Anyhow… You need to add the following as another boot option in the /rpool/boot/grub/menu.lst file;

Use this command in 2008.11 to get details on where your memory is currently being used…

echo ::memstat | pfexec mdb -k

Page Summary                Pages                MB  %Tot ————     —————-  —————-  —- Kernel                     263992              1031   34% ZFS File Data               91917               359   12% Anon                       376867              1472   48% Exec and libs               11484                44    1% Page cache                   3387                13    0% Free (cachelist)             9766                38    1% Free (freelist)             24807                96    3%

Total                      782220              3055 Physical                   782219              3055

Diskpart works quite well extending disk sizes - …unless its the system disk that you need to extend.

Luckily in the virtual world its somewhat easier to move your disks about. This is a quick list of the steps required to increase your system disk… 

You will need to have another virtual machine available to boot into (windows 2003 etc) 

1. Shut down the virtual machine with the system disk you wish to extend
2. Go into virtual machine settings and increase the system drive size to what you require
3. Now you need your spare w2k3 virtual machine or similar. While it is in a shutdown state add the system disk you wish to extend into this machine as another hard disk. Note: select “existing harddrive” and not the default option of  “new harddrive”, and point to the system drive you wish to extend (It is possible to attach this disk as long it is not on and being used) 
4. Power up the spare machine with the newly attached hard drive (the drive you wish to extend) 
5. Logon, open up cmd prompt and type “diskpart” 
6. Now you need to find and select your disk. Type “list disk” to see available disk numbers (most likely the last drive letter). Then type “select disk #”   (# = the number you got from the list command)
7. Next select the volume, similar to above type “list volume” then “select volume #”
8. Type “extend”
9. Type “exit” 
10. Done - shutdown the machine and disconnect the drive you just extended. Be carefull not to DELETE the drive, you only want to disconnect it. 
11. Now you should be able to fire up the original machine and it will have a larger system drive. 

There are obviously other 3rd party utilities to do this but this is handy to know and is actually quite fast.

The following works on CentOs / Fedora / redhat etc… 

Logon to your distro. The packages you need are the kernel-devel.i686, kernel.i686 (if not the latest), and gcc.i386 (complier)

yum -y install kernel.i686 gcc.i386

reboot as the kernel needs to load, then logon again install the kernel dev; 

yum -y install kernel-devel.i686

Now you want to present the virtualbox additions to the cdrom drive on your distro. Click “install additions” on the virtualbox guest console. 

One thing i like about vmware server 2.0, is that you are not forced to use the web console in all cases.

If you are lucky enough to have access to VMware Infrastructure Client 2.5 you can connect via it using the following syntax at the logon screen;

IP address / Name : http://192.168.9.100

If you enter a URL in the host field, use your root and correct password you should be able to logon without issue. Welcome to a nice fast GUI admin console.

How to set the time in Linux; (from a command line)

date -s “09/21/2007 09:20:00”

hwclock –systohc

the second command links the time back to the hardware clock.

Note: within a vm guest it is always advised to install the guest additions as the time on a guest can slowly move away from the correct time.

This is quite a handy app for creating small virtual routers. See the website for more detail… The commandline is similar to cisco - so its good for practice if you are going for your CCNA.

http://www.vyatta.com/products/virtualized.php

Oh - its open source and free!

I’m a bit lazy in most cases and just add a few virtual nics into my VM’s and do the routing though them. But some people may find this handy for a single point to manage networking.

I found this on the web a while back, it sums up most of what you need to know before doing any P2V work (this generally talks about a windows physical to virtual conversion)…. 

http://www.vmware-tsx.com/download.php?asset_id=48

Converter Best Practices

What should I do after I successfully convert my virtual machine?

If you change from a multi-processor system to a uni-processor system you need to manually change the HAL on the Windows server after the conversion. To do this go into Device Manager after the machine first boots and discovers it’s new hardware and then click on Computer then right-click on the processor and select Update Driver. Then select Install from specific location and then Don’t search I will choose the driver to install. Then select show All compatible hardware and select the appropriate processor. For example, if you went from a dual cpu to a single cpu then select ACPI uni-processor PC instead of ACPI multi-processor PC. You will need to reboot once you change this. To verify what HAL you are using you right-click your hal.dll in c:\windows\system32 and select the Version tab and select Internal Name and it should say halmacpi.dll for multi-processor acpi and halacpi.dll for uni-processor acpi.

Next clean up all the non-present hardware after the P2V conversion. To do this go to a CMD prompt and type;

SET DEVMGR_SHOW_NONPRESENT_DEVICES=1 

DEVMGMT.MSC

then select Show Hidden Devices. Delete any old grayed out hardware. Next remove any vendor specific applications/drivers. For example on a HP server you should go to Add/Remove programs and remove any HP management agents, survey utility, array config utility, version control agent, etc. Also check your NIC and make sure there are no vendor specific drivers there (ie. teaming). Check the Services to see if all there is anything vendor specific related there and disable any services that are.