When LVM volume groups collide

I took my hard drive and connected it to another computer with Linux installed. Both HDs had a PV which contained a VG named “vg00”. This collistion was the first time I had encounterd this situation and had to solve it to get access to files on both VGs.

During boot I noticed messages saying there two vg00 on the machine and one is taken precedence over the other. Example message:

[lvm] WARNING: Duplicate VG name vg00: Existing
K0qKAk-Ph5i-BcAX-y4yp-SPF3-TZgj-DufR3L (created here) takes precedence
over K0qKAk-Ph5i-BcAX-y4yp-SPF3-TZgj-DufR3L

The trivial solution is to rename the extra VG to something different and get the access I want to the files. But there are two problems:

1. As the first vg00 has precedence, I can’t do actions on the second one. The LVM commands ignore the second one.
2. I can’t act on the first VG as it’s active for most of the system’s file systems.

Trying vgrename command with the second VG UUID didn’t work. I had to deactivate the first VG first (luckily I have the root FS outside of LVM), rename it, and rename the second VG and then rename the first VG again.

This resulted in having vg00 and vg01. And now I could activate them both and access the files.

I hope to have the time to reproduce the problem on another distro to make sure that’s a general LVM2 problem. Having renmae by UUID would save time to fix the problem and help people who need to boot from CD just to get their VG deactivated (since root FS is on LVM).

August Penguin 2008

In the last two months I’ve been less active regarding free software as life keep me busy with other stuff. Nerver the less I’ve been able to help with orginizing August Penguin – the annual Israeli free software conference (happening the 7th time in a row).

The conference takes half a day and occurs on the first Friday of August. This year we’re back to a two track conference with a tehcnical and non-technical tracks. Each track has 5 lectures, 30 min. each.

Non technical track:

• “Open source by Microsoft” –  Microsoft Israel
• W3C in Israel – Ori Idan
• Building a wordpress community – Blogli staff
• Openoffice.org, the community side + Update on free software in education – Lior Kaplan & Nadav Kavalerchik
• Open Moko – Doron Ofek

Technical Track:

• Bidi in free software – Shoshana Forbes
• Django – Meir Kriheli
• Blender – Shlomi Israel
• Hocr – Kobi Zamir
• Drupal – Lior Kesos

This year with also have ISOC-IL, Microsoft (yes, you’re reading correctly) and Sun as sponsors (and a few smaller companies). Cool to have the “big boys” helping.

As I found out more and more open source people from around the world in Israel, I thought it will be a good idea to write about the conference and invite them. Please be aware that the lectures are in Hebrew. But you can also come to meet the community and talk with the people or take part in our GPG signing party. More info (in Hebrew) at http://august.penguin.org.il and in Facebook’s event info.

Hosting Debian people in Israel

This week was the third time this year I got to host people from Debian in Israel. I find it very interesting to meet people from the project in a totaly different environment from the usuall confrences.

Having a relax talk (and maybe some good food) is a better way to know people than the quick talks I’m used to from more formal meeting. And having the chance to show them a city or the country is of course something I can’t do abroad (:

So, if you’re in the area – let me know. I can’t provide a place to crash, but can still help…

p.s.

The invetation is open to any free software related people… don’t be shy.

How many projects can you identify ?

(taken from http://www.freebsdnews.net/2008/03/11/open-source-community-united/)

To separate or not to separate (the file systems)?

I have to handle some machines of commercial places which has a different standards about thier installations. The main difference is about creating a lot of file system instread of the normal few familiar in most distributions (/, /usr, /var, /tmp, /home).

While they create a FS for each product installed on the machine (a habit taken from UNIX when they didn’t have any meaning of installation other than copying files), they also separate the variale files (e.g. logs or other very active files) of each product.

I’m trying to change these standards to be more close to the FHS (and use the advantenges of RPM/DEB), but one of the main questions I get is what will happen when the FS reach 100%. When everything is separated one product can’t affect another, but that costs with a lot of sysadmin overhead. Leaving everhing variale in /var makes things easy, but hold some risk.

I’d be happy to hear what other sysadmins chose to do…