[Gluster-devel] GlusterFs: Problems with Memory Mapped Files and "apt-get" on debian

[Urban Loesch]

Hi,

I have a problem with "mmap" on my GlusterFs test environment and "apt" 
on Debian.

My environment:
Hardware:
2 different servers for storage
1 server as client
On top of the server I use a virtual server setup (details 
http://linux-vserver.org).

OS:
Debian Sarge with self compiled 2.6.19.2 (uname -r 2.6.19.2-vs2.2.0) and 
latest stable virtual server patch.
GlusterFs: latest mainline 2.4 from repository

What I'm trying to do:
- Create a AFR Mirror over the 2 Servers.
- Mount the Volume on Server 3 (Client).
- Install on the mounted volume the hole virtual Server with Apache, 
MySql and so on.
So I have a full redundant Virtual Server mirrored over two bricks .

After some help from Avati Anand last week the above setup works just 
fine. I tried out Mysql and it works normally (will make some more tests 
in the future).

But now I have the problem with apt.
For example when I try to update the packagelists within the virtual 
server I get the following error:
mastersql:/# apt-get update
Get:1 http://security.debian.org etch/updates Release.gpg 
[189B]                         
...                                                       Hit 
http://ftp.de.debian.org etch/non-free 
Packages                                                                                                         


Fetched 2B in 7s 
(0B/s)                                                                                                                                     

Reading package lists... Error!
E: Couldn't make mmap of 12582912 bytes - mmap (19 No such device)
W: Unable to munmap
E: The package lists or status file could not be parsed or opened.

After some googling I found out, that apt uses "memory mapped files" and 
it seems that apt can't find some device.
But I'm not able to find out which device does it can't find.

Short description of MMAP: 
http://www.ecst.csuchico.edu/~beej/guide/ipc/mmap.html

Have you any idea what can cause this problem? Without GlusterFs as the 
underlaying filesystem the problems not occurs.

thanks
Urban Loesch