Task blocked for more than 120 seconds

[Jorge Eduardo Birck <jorge.birck@gmail.com>]

Hello.

Im having this error:

"task blocked for more than 120 seconds"

In all my Debian Lenny machines, including production servers. I
always use Debian and a never seen a kernel bug that make my servers
freezes before. It makes all my infrastructure (debian and xen  based)
go unstable.

This happend especially when i use high IO disk, but it's hard to
reproduce the error. It happens sometimes when i remove some big
files, while i'm reading anothers. If i'm using DRBD and Xen, it
happens more.

My question is, how can i reproduce this error? Anyone here has the
same problem sometime? Its fixed in the last kernel update? I don't
see this problem in Etch. Until when i will have etch security
upgrades?

I saw that others Linux distributions have the same problem, but no
answers in Google.

Many thanks.