Recently I had gone through a lot of posts from the internet as well as some discussion I had with the persons I met, some of them are concerns about the increasing number of virtual machines into a single physical host which generally putting too much eggs in 1 bucket. They could be right in certain extend, but I will not say they are absolutely correct. They are few missing items that they had forgotten how the IT suppose to run before the virtualization came in to the market with all the capabilities they demostrated VS traditional physical systems.
You may have 30 to 50 VMs into single host today due to high density server with more CPU core or more memory per single system. In the next second, you may face the hardware failure on 1 of the host, there will be around 50 VMs down at 1 time and require another 20 mins before all the virtual machine could be successful restarted on the surviving host. Some of them may consider this is high impact, therefore you decide to restrict the number of virtual machine in single host around 10 to 20 VM per ESX. What happen next, the TCO is high, and ROI is not efficient. Is a tough point for most administrators to choose in this scenario. I will urge you to backward a little bit and look at the scenerio again. Before Virtualization, all the business system that only invested with standalone server without physical clustering, they do not entitle any HA as the aware off. If they want a HA in physical system, they will had to invest extra CAPEX and OPEX to maintain a same set of hardware and operating system, just for failover purpose. Again, even the operating system clustering does not provide 100% uptime.
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Referring to NTPRO Download Chrome OS VMware image post, I’m managed to get Chrome OS running on vSphere update 1 as screen below:
Please make sure you have selected Other 2.6x Linux 32bit as per your guest OS.
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The next version of ESX vSphere or ESX 4 new features – Memory “Hot Add” for virtual machine is not a secret anymore. The most important is Microsoft announced the drop of hot-add support from its roadmap, postponed to an unannounced date, reported by Virtualization.Info which is totally not make sense and it’s confirmed worked on next version of ESX/vCenter.
I would like to share how to configure memory “hot add” for Windows 2003 virtual machine.
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Personally, I would said VMware Tools upgrade on Linux is not as easy as Microsoft Windows virtual machine. Every time VMware Tools upgrade must give me some problem especially on SuSE Linux virtual machine. Anyway this article is not discuss about VMware Tools upgrade and I’m focus on “How to check VMware tools version on Linux using CLI”
Option 1:
# grep buildNr /usr/bin/vmware-config-tools.pl
my $buildNr;
$buildNr = '3.5.0 build-143128';
return remove_whitespaces($buildNr);
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1 of the SLES 10 and 4 of the SLES9 SP3 are having the same problem which is mount in READ only mode today. Damm! I found the root cause and thanks to Linux kernel bug!
According to VMware KB Article 51306
VMware has identified a problem with RHEL5, RHEL4 U4, RHEL4 U3, SLES10, and SLES9 SP3 guest operating systems. Their file systems may become read-only in the event of busy I/O retry or path failover of the ESX Server’s SAN or iSCSI storage.
This issue may affect other Linux distributions based on early 2.6 kernels as well, such as Ubuntu 7.04
The same behavior is expected even on a native Linux environment, where the time required for the file system to become read-only depends on the number of paths available to a particular target, the multi-path software installed on the operating system, and whether the failing I/O was to an EXT3 Journal. However, the problem is aggravated in an ESX Server environment because ESX Server manages multiple paths to the storage target and provides a single path to the guest operating system, which effectively reduces the number of retries done by the guest operating system.
And the solution is:
This is not an ESX Server bug. This Linux kernel bug has been fixed as of version 2.6.22.
Note: This article does not supersede the Guest Operating System Installation Guide, a guest operating system upgrade may require an ESX Server upgrade as well.
For RHEL5, the resolution is to upgrade to Update 1, also refereed to as RHEL5.1
For RHEL4 U3 and RHEL U4, the resolution is to upgrade to Update 5, also refereed to as RHEL 4.5.
For SLES10, the resolution is to upgrade to SP2. For more information, see Novell KB TID 3605538.
For SLES9 SP3, the resolution is to upgrade to SP4, or SP3 Maintenance Release build 2.6.5-7.286.
For more information, see TID 3584352 – Filesystem goes read-only in VMware
For Ubuntu 7.04, the resolution is to upgrade to 7.10
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