VMware Converter 4 – Linux Migration Issue

I have been performing a fair few P2Vs recently and came across an interesting issue with VMware vCenter Converter v4.0.0 Build 146302 when virtualising a Redhat 4 server over to our ESX environment.

I’m adding it here as something to keep an eye out for as its not visible straight away so please double check this after your linux migrations.

The issue we had was that after a successful migration through the converter wizard we were unable to access some of our websites hosted on the linux server, I raised this with VMware and after sending them the log files and some nice diagnosis by the linux team where I am currently working it was found that we had issues with the permissions on some of the files and directories on the server.

VMware Converter Linux P2V does not do anything explicitly to change the user IDs of the files. VMware literally only run tar over ssh to perform the cloning of the files, and this is supposed to preserve the user IDs.

Unfortunately the Helper VM they are running does have its own usernames already, with IDs of their own: 

root:x:0:0:root:/root:/bin/bash

daemon:x:1:1::/:

nobody:x:65534:65534::/tmp:

guest:x:500:500:Guest Account:/home/guest:/bin/bash

The repercussion is that a file owned by “nobody” on the source will also be owned by “nobody” in the helper VM.  But since nobody is 99 on the source and 65534 in the helper, the files owning UID was changed from 99 to 65534.

Due to the change of UID/GID the files will appear to change from being owned by “nobody” to “nfsnobody”. nfsnobody is a default user & group with UID/GID 65534 on both RHEL 4 & 5 installs so this affects both versions.

VMware were kind enough to issue us a fix for this issue and have advised it would be fixed in the next release but in the meantime please make sure you double check the permissions after a ‘successful’ migration.

4 thoughts on “VMware Converter 4 – Linux Migration Issue”

  1. Khatib Mechentel :
    Hello, nice work.
    We tried this release of Converter and the new one (4.0.1 build 161434). Actually with the 4.0.0 version all the files originally owned by nobody are owned by nfsnobody after the conversion. With the version all the files originally owned by nobody remain owned by nobody. I assume Vmware has resolved this issue. I have read the 4.0.1 release notes, but nothing about this issue ! I’m going to translate your article in french so all the french speaking community could read it.

    1. Sounds great, im glad this helped someone out, took us a fair bit of fault finding ! P.S. Im in France whilst answering this 😉

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