VCB for NFS

Read this post: http://storagefoo.blogspot.com/2007/09/vmware-on-nfs-backup-tricks.html. It discusses a free alternative for VMware Consolidated Backup, but over NFS instead of Fibre Channel (SAN).

The thing we want Softgrid to do (Active Upgrade+)

This entry started as a comment on
http://blogs.technet.com/softgrid/archive/2007/09/25/methods-for-upgrading-or-updating-virtualized-applications.aspx

The thing with Active Upgrade is that (as the article points out), the user gets the update automatically on next launch of the application. This is a major step forward for application updates. However, it does not solve the whole application testing problem: before pushing changes to the users, I need to test the application. In order to test, both version need to coexist but with Softgrid it is not X and Y but X or Y. The fact that a rollback to an earlier version of an active upgrade is not possible adds to the complexity.

What I basically want is:
1) Make a parallel application branch Y (as it is called in the article) from version X
2) Test this branch (without impacting the existing version)
3) Update the parallel application branch if required (using active upgrade)
4) When tests are successful, use Active Upgrade to update the production version X

This scenario is inherently not feasible because in stage 1, a new asset directory and a new GUID is created so that settings are stored in a different location.

The scenario that comes closest to what I want is the following:
1) Make a parallel application branch Y
2) Test this branch
3) When tests are successful, apply exactly the same procedure to the original version X, but this time using active upgrade.

The main issue in this case is the fact that you need to record the exact upgrade scenario in order to apply it again in step 3.

An other workaround exists, though:
1) Make an active upgrade
2) Test this update by manually importing the SFT file on the client (instead of streaming it)
3) When successful, do the update centrally with active upgrade.

I hear you thinking: but we have a Test envionment in order to do application tests. Ok, right, do you have a test copy for every production database to name just one example of why production tests may be required.

File Versioning

File versioning is something I have been interested in since I started out doing programming for my simulations back in university. Later, I was lucky enough to be able to use (La)TeX to type my PhD thesis, which enabled me to use CVS to track changes to my text.

Years later, I'm less lucky in that I do not use LaTeX anymore (neither do I program in C ;-), but I do still want my documents and scripts to be versioned, especially when actively working on them. I used to create copies for major versions of Word or PowerPoint documents. At the end, I deleted most of the intermediate copies because they were no longer relevant.

But now, everything has changed dramatically... due to FileHamster. FileHamster is a versioning tool, that automatically tracks changes to files and directories and allows you to keep those changes, revert to earlier versions, backup and by means of some handy plugins add notes and remarks to versions. And ... it is free !



Behind the scenes, the tool creates a copy of every version you save, so you do use a lot of space for big files, but you cannot blame a tool for the fact that most of the files we work with nowadays are composed of binary data!

ESX 3.0 on Workstation 6 (Update)

By accident, I found out that on the website of XtraVirt, a series of white papers has been published around this theme. Starting from installing ESX in a VM, to creating a NAS virtual machine for hosting your virtual-virtual machines and doing VMotion etc. Interesting...

ESX 3.0 host as NAS server

A client asked me to configure one of their ESX hosts as an NFS server for hosting ISO files. This host had 300GB of remaining disk space which would otherwise be just a waste. So, I started right away: creating an export directory, formatting the file system (converting vmfs to ext3), tested mounting it from different ESX host... no problem!

Until I tried to import the new volume as a datastore via the VI Client, then the VI Client complains about the fact that the NFS server does not support NFS v3 over TCP. Although NFS over TCP has been around for ages, it appears to have been stripped from the NFSD module in the service console. Is this done on purpose by VMware to make sure you can not easily run a standalone ESX host with shared storage out-of-the-box?

Anyhow, by recompiling the NFSD module (luckily VMware has added the source for the kernel) one can make it work. See this document (in dutch) for a procedure on how to make this work. Works like a charm!