Red Hat Linux 7.1 for pSeries (64-bit) - Seawolf Release Notes
==============================================================
This document describes features that are new to Red Hat Linux 7.1, but may
not have been available prior to our documentation being finalized. For
the very latest information, please read the RELEASE-NOTES file on the Red
Hat Linux CD #1.
Last-Minute Changes
-------------------
o When upgrading a machine that last ran Red Hat's 32-bit kernel,
you will need to set the machine's hardware clock manually. To set
the hardware clock, follow these steps:
1. when the System Boot Configuration screen appears, switch to
the interactive shell terminal by pressing <ctl>+<alt>+<f2>
2. execute the command
chroot /mnt/sysimage
3. set the hardware clock using the command
/usr/sbin/hwclock --set --date="9/22/1996 16:45:05"
(using the correct date, of course)
4. set the system clock using the command
/usr/sbin/hwclock --hctosys
5. execute the command
exit 0
6. return to the installer by pressing <ctl>+<alt>+<F7>
o The linux kernel cannot properly determine the amount of video RAM in
Matrox G200 graphics adapters without a kernel parameter to specify
which type of memory the adapter has. If you find the installer
incorrectly reporting the amount of memory on your graphics adapter,
you may want to try adding the following kernel parameter to the
kernel commandline:
video=matrox:memtype:4
This generally allows the kernel to properly determine the amount of
video memory present in Matrox G200 cards.
o Reminder regarding NFS, FTP, or HTTP installations -- Because the Red
Hat Linux 7.1 installation program is capable of installing Red Hat
Linux from multiple CD-ROMs, if you intend to support NFS, FTP, or
HTTP installations it is no longer possible to simply mount a single
Red Hat Linux CD-ROM, and install from it.
Instead, you must copy the RedHat directory from each CD-ROM
comprising Red Hat Linux 7.1 onto a disk drive:
- Insert CD 1
mount /dev/cdrom /mnt/cdrom
cp -var /mnt/cdrom/RedHat /location/of/disk/space
umount /mnt/cdrom
- Insert CD 2
mount /dev/cdrom /mnt/cdrom
cp -var /mnt/cdrom/RedHat /location/of/disk/space
umount /mnt/cdrom
You must then make /location/of/disk/space accessible to the
installation program (for example, exporting it for NFS
installations):
- Export /location/of/disk/space
Installation-Related Enhancements and Changes
---------------------------------------------
The Red Hat Linux 7.1 installation program includes a number of new
features. For more information, please refer to the Official Red Hat Linux
Installation Guide.
o Swap-related issues -- The 2.4 kernel is more aggressive than the 2.2
kernel in its use of swap space. However, as with previous versions
of the kernel, the optimal sizing of swap space remains dependent on
the following:
- The amount of RAM installed
- The amount of disk space available for swap
- The applications being run
- The mix of applications that are run concurrently
No rule-of-thumb can possibly take all these data points into
account. However, we recommend the following swap sizes:
- Single-user systems with less than 128MB physical RAM: 256MB
- Single-user systems and low-end servers with more than 128MB
physical RAM: two times physical RAM (2xRAM)
- Dedicated servers with more than 512MB physical RAM: highly
dependent on environment (must be determined on a case-by-case
basis)
While it is certainly possible for systems with specific
configurations and application loads to run with less (or even no)
swap space, these guidelines attempt to ensure that you will not run
out of swap. The old saying certainly applies to swap space:
"It's better to have it and not need it, than to need
it and not have it."
o Swap-related issues specific to upgrades -- If you are performing a
fresh Red Hat Linux 7.1 installation, the sizing of swap partitions
is a relatively-straightforward process. However, if you have an
older Red Hat Linux system that you wish to upgrade to Red Hat Linux
7.1, please keep in mind that the size of the swap partition(s) you
had previously created may no longer be sufficient.
The Red Hat Linux 7.1 installation program now examines the available
swap space. If insufficient swap space exists, it will configure
additional swap space in the form of a swap file. The installation
program will do this by asking you to select a partition on which to
create a swap file. You will also be asked for the desired size of
the new swap file.
(NOTE: In no instance will the Red Hat Linux 7.1 installation program
create a swap partition or file larger than 2GB. Should your swap
requirements exceed this size, you will need to address this after
the installation has completed.)
o XFree86 4.1.0 -- The Red Hat Linux 7.1 installation program includes
improved test screens and better detection of video memory, doing
more than ever to help you get everything correct with a minimum of
fuss.
o Firewall Configuration -- For added security, you can now configure a
firewall as part of your system installation. You can choose from
two levels of security, as well as choosing which common system
services should be allowed or disallowed by default.
Please note that both "medium" and "high" firewall settings will
cause RPC-based services (such as NIS or NFS) to be blocked, and
thus fail.
o Hard Drive Installation - ISO images are now required for hard drive
installations, making it no longer necessary to copy and install the
entire tree. Instead, simply put the required ISO images in a
directory. During the hard drive installation, point the Red Hat
Linux installation program at that directory. In addition, since Red
Hat publishes MD5 checksums for all ISO images, it is now possible to
ensure that you are using officially-released software by running the
md5sum program against your ISO images, and comparing the checksums
against the ones published by Red Hat.
o Language Selection -- Language selection has been significantly
re-vamped. It is now possible to install in one language, but
specify that the system, after installation, will operate in another
language.
o Disk Druid Improvements -- Disk Druid now detects partition table
inconsistencies, such as partitions that do not end on cylinder
boundaries. This can be caused if the geometry of a hard disk drive
is detected differently than when the drive was originally
partitioned. In these cases, we recommend that you use the fdisk
program to more closely inspect these inconsistencies, or choose to
skip the drive entirely.
o Improved Rescue Mode -- Rescue mode now attempts to mount the
filesystems listed in /etc/fstab (assuming the root filesystem can be
found). The filesystems are mounted under /mnt/sysimage. This
eliminates a very confusing step for users using rescue-mode for the
first time.
o New Authentication Configuration Security Option -- Authentication
configuration now includes the ability to use Transport Layer
Security (TLS) when performing lookups. TLS allows LDAP clients to
use an encrypted connection when performing authentication.
o Miscellaneous Installation Program Improvements -- Overall, there are
many additional tests and checks performed to catch potential
problems which previously caused tracebacks (installer crashes).
This should reduce the number of poor out-of-box experiences for
newer users.
System-Related Enhancements and Changes
---------------------------------------
There are many features new to Red Hat Linux 7.1 that are not part of the
installation process. Some new features are server-oriented programs,
while others are new applications or desktop environment changes. This
list will provide a bit more information about what to expect from Red Hat
Linux 7.1 once you are actually using the OS.
o Improved USB Support -- The 2.4 kernel gives Red Hat Linux 7.1 more
mature USB support than previous versions of Red Hat Linux. It
contains more drivers, and includes support for storage devices such
as CD-ROMs. It also supports "hot-pluggable" or removable devices --
if a supported device is plugged in after booting, the necessary
drivers will load automatically.
o Removable media drives automatically added to /etc/fstab -- Red Hat
Linux 7.1 now includes the ability for users to mount and unmount
removable media drives. This is done by the updfstab program (which
is part of the kudzu boot-time hardware configurator). It adds and
removes the necessary entries in /etc/fstab. Note that each entry
managed by updfstab contains the new "kudzu" option -- this acts as a
token indicating that the entry may subsequently be removed; if you
wish to permanently add such an entry to your fstab, simply remove
the "kudzu" option.
Hotpluggable devices are handled through a combination of cardmgr,
hotplug, updfstab, and pam_console_apply. When the kernel notifies
hotplug or cardmgr that a new storage device has been attached to the
system, updfstab is run to add the new entries to the fstab. Then,
updfstab runs pam_console_apply, which uses the rules specified in
/etc/security/console.perms to give the current console user access
to the device.
o IMAP server changes -- The IMAP server now defaults to using its
built-in SSL support instead of stunnel's tunneling support.
Accordingly, the name of the certificate file used by imapd has
changed from stunnel.pem to imapd.pem. Users upgrading from previous
releases of Red Hat Linux will need to rename, copy, or create a
symbolic link to their existing certificate.
o Sendmail -- By default, sendmail does not accept network connections
from any host other than the local computer. If you want to
configure sendmail as a server for other clients, please edit
/etc/mail/sendmail.mc and change DAEMON_OPTIONS to also listen on
network devices, or comment out this option all together. You will
need to regenerate /etc/sendmail.cf by running:
m4 /etc/mail/sendmail.mc > /etc/sendmail.cf
Note that you must have the sendmail-cf package installed for this to
work.
o Other package highlights:
- Ogg Vorbis audio encoder/decoder
- Mozilla Web browser
- LSB-compliant SGML and XML packages
- KDE 2.1 and KOffice
- BIND 9.x with DNSsec support and remote named control
- SSL support in links, slrn, OpenLDAP, and pine
- Pine 4.33
- Quanta HTML editor (on Powertools)
- Postfix and exim (on Powertools) include SSL/TLS support
o Deprecated Packages -- the following packages are deprecated, and
could disappear in a future release:
- AfterStep
- Netscape 4.x
- Qt 1.x
- KDE v1 compatibility libraries / build environment
- elm
- linuxconf
- ncpfs
- mars_nwe
Documentation-Related Enhancements and Changes
----------------------------------------------
o Additional documentation regarding the /etc/sysconfig/vncservers file
-- Due to time constraints, the following information was not
available prior to the Red Hat Linux Reference Guide's print date.
The /etc/sysconfig/vncservers file configures how the Virtual Network
Computing (VNC) server starts up. VNC is a remote display system
which allows you to view a desktop environment not only on the
machine where it is running but across different networks (from a LAN
to the Internet) and using a wide variety of machine architectures.
It may contain the following:
VNCSERVERS=<value>, where <value> is set to something like "1:fred",
to indicate that a VNC server should be started for user fred on
display :1. User fred must have set a VNC passwd using vncpasswd
before attempting to connect to the remote VNC server.
Note that when you use a VNC server, your communication with it is
unencrypted, and so it should not be used on an untrusted
network. For specific instructions concerning the use of SSH to
secure the VNC communication, please read the information found at
http://www.uk.research.att.com/vnc/sshvnc.html. To find out more
about SSH, please refer to the Red Hat Linux Reference and
Customization Guides.
ppc64 7.1
