Re: BUG #5725: server couldn't start when installing on liveCD

Hello

Thank you very much.
However, postgresql 8.4 can be installed on ubuntu 9.10 live cd. Why wouldn't it work with 10.10 live cd?
I'm aware of RAM considerations, but my database is very light (a few hundred records), so there is no problem running it on a liveUSB.
Thank you very much in advance for your help.

Vincent

Le 26 oct. 2010 à 01:52, Craig Ringer <craig(at)postnewspapers(dot)com(dot)au> a écrit :

On 10/26/2010 02:44 AM, VMaury wrote:

2010-10-25 08:45:56 UTC PANIC: could not open file
"pg_xlog/000000010000000000000000" (log file 0, segment 0): Invalid
argument

This bug has been reported by someone else (in spanish):
https://bugs.launchpad.net/ubuntu/+source/postgresql-8.4/+bug/658857

However, this install works perfectly once Ubuntu is installed.
Why is there a difference between install and live?
Thank you very much for your help,

The live CD uses a union file system over the squashfs from the CD. I seem to remember that the writable part of the union is a tempfs, but I'm not 100% sure of that. Anyway, the union file system and/or the underlying tempfs are probably missing features required for PostgreSQL's operation.

You can probably get it to run by pre-creating the postgresql data directory and mounting a real file system on it, without the union with squashfs. A dedicated tempfs might work, so try that. If it doesn't, you'll need some writable storage (a partition on the computer's hard disk, an external HDD, even a USB key if you're prepared for horrifyingly bad performance) to put a real file system like ext3 on.

Even if tempfs works, be aware that it uses your system's RAM - and when that runs low, spills to swap space. If there isn't enough RAM and there's no swap space, it'll fail. Of course, the data also goes away on reboot. It's a very bad place to run PostgreSQL for anything but the most utterly trivial toy experimentation.

--
Craig Ringer