Debian Version for System Z

[Saulo Silva]

Hi all,

I would like to know about the current release of the Debian Linux for Z .
And if that is a 64bit linux compile .

Best Regards ,

Saulo Augusto Silva .

[Stephen Powell]

Post by Saulo Silva
I would like to know about the current release of the Debian Linux for Z .
And if that is a 64bit linux compile .

I'm not sure I understand your question. Debian GNU/Linux has had an
s390 port since 3.0 (Woody). Some other Linux distributions treat s390 and
s390x as separate architectures. Debian does not. Debian treats both ESA/390
processors and z/Architecture processors as belonging to the s390 architecture,
or "port". Debian does provide two different flavors of kernel, however.
The s390 flavor runs on either an ESA/390 processor or a z/Architecture
processor. The s390x flavor runs only on a z/Architecture processor.
Older releases of Debian provided only the s390 flavor. For a while, a single
release of Debian provided both flavors, at the user's choice. I'm not
sure which was the first release that provided the s390x flavor, but I do
know that Lenny (Debian 5.0) was the last release to provide the s390 flavor.
Starting with Squeeze (Debian 6.0), only s390x kernel flavors are provided.

The s390x flavor of kernel puts the processor into z/Architecture mode shortly
after IPL, and the processor stays in z/Architecture mode thereafter. Debian
does not have a 64-bit user space, however. The kernel (and it's modules)
run in 64-bit mode. But user-space applications currently run in 31-bit mode.
Thus, a single user-space process is limited to 2G of (virtual) memory.
But the system can make use of more than 2G of real memory, since the kernel
can allocate (in theory) up to a 2G address space to EACH user-space process.

HTH
--
.''`. Stephen Powell
: :' :
`. `'`
`-

[Saulo Silva]

Hi Stephen ,

You answered me what I want to understand . Just to clarify . The other
distro treat s390 as 31-bits and s390x as 64-bits and Debian doesn't . My
question is : I will be able to run the s390x applications from ISVs based
on other s390x linux distro at the Debian 6 running with 390x kernel ?
could I say that we have the same Linux from any other s390x distro that we
have with s390x Debian ?

thanks in advanced ,

Saulo Silva

Post by Stephen Powell

Post by Saulo Silva
I would like to know about the current release of the Debian Linux for Z

.

Post by Saulo Silva
And if that is a 64bit linux compile .

I'm not sure I understand your question. Debian GNU/Linux has had an
s390 port since 3.0 (Woody). Some other Linux distributions treat s390 and
s390x as separate architectures. Debian does not. Debian treats both ESA/390
processors and z/Architecture processors as belonging to the s390 architecture,
or "port". Debian does provide two different flavors of kernel, however.
The s390 flavor runs on either an ESA/390 processor or a z/Architecture
processor. The s390x flavor runs only on a z/Architecture processor.
Older releases of Debian provided only the s390 flavor. For a while, a single
release of Debian provided both flavors, at the user's choice. I'm not
sure which was the first release that provided the s390x flavor, but I do
know that Lenny (Debian 5.0) was the last release to provide the s390 flavor.
Starting with Squeeze (Debian 6.0), only s390x kernel flavors are provided.
The s390x flavor of kernel puts the processor into z/Architecture mode shortly
after IPL, and the processor stays in z/Architecture mode thereafter.
Debian
does not have a 64-bit user space, however. The kernel (and it's modules)
run in 64-bit mode. But user-space applications currently run in 31-bit mode.
Thus, a single user-space process is limited to 2G of (virtual) memory.
But the system can make use of more than 2G of real memory, since the kernel
can allocate (in theory) up to a 2G address space to EACH user-space process.
HTH
--
.''`. Stephen Powell
`. `'`
`-
--
with a subject of "unsubscribe". Trouble? Contact

[Saulo Silva]

Hi Stephen ,

You answered me what I want to understand . Just to clarify . The other
distro treat s390 as 31-bits and s390x as 64-bits and Debian doesn't . My
question is : I will be able to run the s390x applications from ISVs based
on other s390x linux distro at the Debian 6 running with 390x kernel ?

Could I say that we have the same Linux from any other s390x distro that we
have with s390x Debian ?

thanks in advanced ,

Saulo Silva

Post by Stephen Powell

Post by Saulo Silva
I would like to know about the current release of the Debian Linux for Z

.

Post by Saulo Silva
And if that is a 64bit linux compile .

I'm not sure I understand your question. Debian GNU/Linux has had an
s390 port since 3.0 (Woody). Some other Linux distributions treat s390 and
s390x as separate architectures. Debian does not. Debian treats both ESA/390
processors and z/Architecture processors as belonging to the s390 architecture,
or "port". Debian does provide two different flavors of kernel, however.
The s390 flavor runs on either an ESA/390 processor or a z/Architecture
processor. The s390x flavor runs only on a z/Architecture processor.
Older releases of Debian provided only the s390 flavor. For a while, a single
release of Debian provided both flavors, at the user's choice. I'm not
sure which was the first release that provided the s390x flavor, but I do
know that Lenny (Debian 5.0) was the last release to provide the s390 flavor.
Starting with Squeeze (Debian 6.0), only s390x kernel flavors are provided.
The s390x flavor of kernel puts the processor into z/Architecture mode shortly
after IPL, and the processor stays in z/Architecture mode thereafter.
Debian
does not have a 64-bit user space, however. The kernel (and it's modules)
run in 64-bit mode. But user-space applications currently run in 31-bit mode.
Thus, a single user-space process is limited to 2G of (virtual) memory.
But the system can make use of more than 2G of real memory, since the kernel
can allocate (in theory) up to a 2G address space to EACH user-space process.
HTH
--
.''`. Stephen Powell
`. `'`
`-
--
with a subject of "unsubscribe". Trouble? Contact

[Philipp Kern]

Post by Saulo Silva
You answered me what I want to understand . Just to clarify . The other
distro treat s390 as 31-bits and s390x as 64-bits and Debian doesn't . My
question is : I will be able to run the s390x applications from ISVs based
on other s390x linux distro at the Debian 6 running with 390x kernel ?
Could I say that we have the same Linux from any other s390x distro that we
have with s390x Debian ?

There are basic s390x support libraries in the archive (libc6-s390x,
some lib64* libraries). With those I'm able to run IBM Java 64bit
just fine on Debian. If the ISV applications are not linked
statically to all the libs Debian does not provide, then they won't
work. I'd assume that most are, though.

You can check it by running ldd against the binary application.
For IBM Java I get this:

***@i43z10deblin0:/opt/ibm-java-s390x-60/bin$ ldd ./java
libpthread.so.0 => /lib64/libpthread.so.0 (0x0000020000010000)
libjli.so => /opt/ibm-java-s390x-60/bin/./../jre/lib/s390x/jli/libjli.so (0x000002000002f000)
libdl.so.2 => /lib64/libdl.so.2 (0x000002000003a000)
libc.so.6 => /lib64/libc.so.6 (0x000002000003f000)
/lib64/ld64.so.1 => /lib/ld64.so.1 (0x000002aaaaaaa000)

You'll get a "not found" in place of a library in there if you miss
one.

Kind regards
Philipp Kern

[Stephen Powell]

Post by Saulo Silva
You answered me what I want to understand . Just to clarify . The other
distro treat s390 as 31-bits and s390x as 64-bits and Debian doesn't . My
question is : I will be able to run the s390x applications from ISVs based
on other s390x linux distro at the Debian 6 running with 390x kernel ?
could I say that we have the same Linux from any other s390x distro that we
have with s390x Debian ?

Well, as Bill Bitner often says, "It depends." It depends on what you mean
by an ISV. Obviously that means "Independent Software Vendor". But let's
take a specific example. Let's suppose that you want to run IBM's DB2
Universal Database for Linux. That's a closed-source, proprietary, object-
code-only product. The last time I checked, they did not offer a version
packaged for Debian. You see, Red Hat and Suse are "IBM Business Partners".
And they both use the Red Hat Package Management format (.rpm format).
So IBM's binary packages are in .rpm format.

Debian uses the Debian Package Management format (.deb format). Although
it is theoretically possible, in some cases, to install a .rpm package to
a Debian system (using "alien" for example), it's probably not something you
want to do. And in this specific case, it may not even be possible. If you
try to install an s390x-architecture rpm package on Debian, you're likely
to see the install fail with an architecture conflict (s390 vs s390x).
Plus, the .rpm package was compiled with the C compiler that was current in
the intended target distribution, which may or may not work with the C run-
time libraries in Debian, etc. In short, only install a binary package
that has specifically been packaged for Debian. If you have the source
code, you can compile it yourself, if need be. But lots of luck getting
the source code for DB2 from IBM. ;-)

On the other hand, if you are using postgresql or mysql, which are open
source, there's no problem. The source code is available, and you can
compile it yourself. But in most cases, that's not necessary. Both of
those products, as well as about 25,000 others, are already packaged for
Debian.
--
.''`. Stephen Powell
: :' :
`. `'`
`-

[Philipp Kern]

Stephen,

Post by Stephen Powell
Well, as Bill Bitner often says, "It depends." It depends on what you mean
by an ISV. Obviously that means "Independent Software Vendor". But let's
take a specific example. Let's suppose that you want to run IBM's DB2
Universal Database for Linux. That's a closed-source, proprietary, object-
code-only product. The last time I checked, they did not offer a version
packaged for Debian. You see, Red Hat and Suse are "IBM Business Partners".
And they both use the Red Hat Package Management format (.rpm format).
So IBM's binary packages are in .rpm format.
Debian uses the Debian Package Management format (.deb format). Although
it is theoretically possible, in some cases, to install a .rpm package to
a Debian system (using "alien" for example), it's probably not something you
want to do. And in this specific case, it may not even be possible. If you
try to install an s390x-architecture rpm package on Debian, you're likely
to see the install fail with an architecture conflict (s390 vs s390x).
Plus, the .rpm package was compiled with the C compiler that was current in
the intended target distribution, which may or may not work with the C run-
time libraries in Debian, etc. In short, only install a binary package
that has specifically been packaged for Debian. If you have the source
code, you can compile it yourself, if need be. But lots of luck getting
the source code for DB2 from IBM. ;-)

usually repacking IBM's RPMs as debs isn't a problem. I do that for TSM on
i386, amd64 and s390 and it works just fine. (That said, not with alien,
RPM would work too.) Most ISV software conforms to LSB and thus they ship
everything that's not guranteed to be present in the base system. So as
long as all this stuff is available in 64bit form we ought to be safe
if ISVs are compliant.

If something needs fixing please tell us.

(That said: non-proprietary software is more fun, too.)

Kind regards,
Philipp Kern

[Stephen Powell]

Post by Philipp Kern
usually repacking IBM's RPMs as debs isn't a problem. I do that for TSM on
i386, amd64 and s390 and it works just fine. (That said, not with alien,
RPM would work too.) Most ISV software conforms to LSB and thus they ship
everything that's not guranteed to be present in the base system. So as
long as all this stuff is available in 64bit form we ought to be safe
if ISVs are compliant.

Well then things have changed since I last messed with this. I remember
trying to get an SSLSERV server for TCP/IP for z/VM 5.3.0 running. Back
then the SSLSERV virtual machine needed to run Linux. IBM supported only
Red Hat and Suse, of course, and they had only rpm packages. I had a devil
of a time getting it to work.

Also, if you do get it to work (almost) and have problems with it, and
call IBM for support, IBM will tell you that Debian is not a supported
environment and hang up. And then what good is the support that you're
paying for?

I love Debian for s390, but if I were going to use it I would want to use
it in an all-open-source environment.
--
.''`. Stephen Powell
: :' :
`. `'`
`-