Configuration

Introduction | Top | Installation

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Downloading

• Log on one of the frontend nodes of the Blue Gene (a login node or a service node).

• Download the ZeptoOS tarball from the ZeptoOS download page.

• Extract the sources from the package:

$ tar xjf ZeptoOS-*.tar.bz2

Configuring

Change to the top-level ZeptoOS-<version> directory:

$ cd ZeptoOS-<version>

A configure script is provided to set the pathnames to various system directories.

$ ./configure

If invoked without any arguments, it will use the defaults, which should be appropriate if ZeptoOS is configured on a system with a supported BG/P driver version. The pathnames can be changed with the help of a user interface by invoking the script as follows:

$ ./configure --edit

This will display the following menu:

Please select the top item (BG/P DIST_DIR). The screen will change to:

The following options are available:

DRV_DIR

The directory with the BG/P driver tree. The default (/bgsys/drivers/ppcfloor/) is a link pointing to the currently active driver.

BGP_CROSS

A prefix to the pathnames of the GNU cross-compilers used to build the compute node and I/O node software.

BGCNS_H_PATH and BGCNS_H

The location of a file needed to rebuild the kernel (these options are temporary and will be removed in the next version).

OS_DIR

The directory with the supplementary I/O node software used when booting the I/O nodes. It needs to be set to match the BG/P driver version being used.

The second top-level menu (Debugging) has only one option:

ADD_DEBUG_TOOLS

Check this option to include gdb and strace in the compute node ramdisk. They are not included by default because of their size.

The third top-level menu (Kernel Profiling) is discussed in the (K)TAU section

Select Exit (multiple times if needed) and confirm if you want to save any changes made.

Building

To start using the pre-built binaries simply type:

$ make

On the first invocation, this will ask for a root password to use on I/O nodes:

Create root password for I/O Node
   Leave the password field empty if you want to disable root login
   New password:

Security note: root-level access to I/O nodes should only be given to trusted individuals. A root user can access and modify files of all users in the system.

Once a password has been entered and confirmed, make will use pre-built kernel images, and will build the ramdisks from pre-built tools and utilities. The following generated files will be placed in the top-level directory:

BGP-CN-zImage-with-initrd.elf

A merged ZeptoOS compute node Linux and compute node ramdisk file.

BGP-ION-ramdisk-for-CNL.elf

ZeptoOS I/O node ramdisk for use with the ZeptoOS compute node Linux.

BGP-ION-ramdisk-for-CNK.elf

ZeptoOS I/O node ramdisk for use with the IBM CNK (optional).

BGP-ION-zImage.elf

ZeptoOS I/O node kernel.

It is possible to rebuild individual ZeptoOS components using one of the following make targets (the list is also available by typing make help or make menu):

bgp-ion-ramdisk-cnk

Rebuilds the I/O node ramdisk for the IBM CNK.

bgp-ion-ramdisk-cnl

Rebuilds the I/O node ramdisk for the ZeptoOS compute node Linux.

bgp-cn-linux

Rebuilds the compute node ramdisk and embeds it into a compute node kernel image.

bgp-ion-linux-build

Rebuilds the I/O node kernel.

bgp-cn-linux-build

Rebuilds the compute node kernel and ramdisk and merges them.

bgp-all-pkg-rebuild

Rebuilds all packages from sources.

(the following maketargets are mostly for internal use)

bgp-ion-linux

Copies a recently rebuilt I/O node kernel if one is available; otherwise, uses a prebuilt binary (will not rebuild the kernel).

bgp-all-pkg-smart

Copies recently rebuilt packages if available; otherwise, uses prebuilt binaries (used when preparing to rebuild ramdisks).

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Introduction | Top | Installation