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Linux for Big Iron

Archives of linuxvm.org

04/04/2005 - Christian Borntršger of IBM said that he would look into a performance problem of a SLES9 user that was seeing a 30 second delay during some system IPLs when the hotplug code was detecting 32 processors. This was happening on a Multiprise 7060 with 1 CPU. Christian said that VM APAR VM63654 should be installed on any system that was going to be using CPU hotplug, but a 30 second delay could probably be improved upon.

04/05/2005 - Gerhard Hiller of IBM reported the following updates on the DeveloperWorks web site:

  • April 2004 stream
    • kernel 2.6.5 recommended kernel patch with bug fixes

04/05/2005 - In response to a request for examples of successful migration of Linux applications from Intel to Linux/390, Doug Fairobent said that ACTS Corporation was one such case.

04/05/2005 - In response to a request for how to get a copy of SLES9 SP1, Mark Post stated that a z/Journal article he had written tells how to get a no-cost trial license (including maintenance) for either SUSE or Red Hat.

04/06/2005 - In response to a request for any information about NJE/RJE interoperability tools that would allow a Linux/390 system to submit jobs to z/OS, David Boyes of Sine Nomine announced that they had developed commercial tool to do just that.
"We've developed a NJE implementation for Linux on (Intel, PPC, zSeries), Solaris, AIX, and HP/UX. This gadget allows use of standard NJE networking capabilities for file transfer, printing and interactive messaging to communicate bidirectionally from any of the above OSes to/from NJE-enabled operating systems as a peer. Full NJE routing and multi-stream capability is supported, as is SENDFILE and msg support (and as soon as I finish the CTC testing, I'll add support for syslog message log transfer to PROP or other NJE-based tools).

"The current implementation supports TCPNJE with RSCS and VSE; a maintenance release in August (we're still testing with some of the more esoteric stuff) will support real CTC connections. It is supported for LPAR and VM guests, and the CTC version will support JES(2,3), and TPF as well. It can be installed on an existing Linux or Unix system, or supplied as a appliance (OS and application together). The CTC version supports up to 32 CTC connections and a large number (limited by storage) of TCPNJE connections. No VTAM or other communications engine (such as CS for Linux) is required -- this is a completely native implementation.

"The implementation includes cmdline utilities for MSG and SENDFILE, mail and printer interface, and a API programming library. The TCPNJE support uses SSL encryption for TCP connections (compatible with the SSL Server Enabler) if you enable it and are running on an OS with SSL wrapper support."

04/07/2005 - In response to a question about possibly using CTC connections over FICON, David Boyes recommended reading a paper by Shimon Lebowitz on just how to do that.

04/08/2005 - In a discussion about how to add a new network interface to a SLES9 system without using YaST, David Kreuter talked about copying the configuration files from /etc/sysconfig/network, and then modifying them. Hannes Reinecke of SUSE added this comment: "And do not forget to copy over the hardware configuration file in /etc/sysconfig/hardware/hwcfg-XXX and modify it with the appropriate parameters. Have a look in /etc/sysconfig/hardware/skel for samples. Full description can be found in /usr/share/doc/packages/sysconfig/README.s390."

04/13/2005 - In response to a question about how to use IPTABLES to set up a Linux firewall, Istvan Nemeth recommended a website that talks about this.

04/13/2005 - Vic Cross reported a problem with his Guest LAN not working after applying SP1 to his SLES9 system. The solution seemed to be putting on addtional z/VM maintenance. Dennis Musselwhite took the opportunity to point people to the IBM web page that deals with virtual networking, including appropriate CP maintenance levels.

04/13/2005 - Neale Ferguson was the first to report the appearance of the Open Source version of Object Rexx (orexx), which was contributed by IBM. Neale also commented that it compiled cleanly on his SLES9 system, but he had to make a slight change to the spec file for the RPM:

--- oorexx.spec.old     2005-04-13 13:11:53.452401703 -0400
+++ oorexx.spec 2005-04-13 12:38:27.262401703 -0400
@@ -94,15 +94,15 @@
Mark Post reported that it built cleanly on Slack/390 as well, without having to change anything.

04/14/2005 - Adam Thornton noted that a new version of OpenMosix was out that moved a lot of the patch from the kernel to userspace.

04/15/2005 - Adam Thornton of Sine Nomine Associates announced that version 0.5 of SysVInit has been released. "Improvements over 0.4 include support for VSWITCH coupling for Linux guests and global VM performance settings. Barring the discovery of major bugs, this is likely to be the last release before 1.0."

Adam did warn of one know issue. "SysVInit generates log files on AUTOLOG1's 191-disk, but does not automatically clean them up. So every so often you need to purge them manually, or your 191-disk will fill up and then PROP will fail to run. This behavior has been present in every release of SysVInit, so if you're running it at all, you should probably check your 191-disk and clean it up if necessary."

04/15/2005 - Rich Smrcina announced that he has written a syslog daemon for VSE. "It's sole purpose is to receive syslog messages from a Linux (or any compatible Unix) system. When a message is received it is displayed on the VSE system console. Console automation software can then use the message to trigger an action, for instance, to submit a job."

04/19/2005 - In response to a question about migrating Samba user and machines accounts to an LDAP server on SLES9, Mike MacIsaac recommended using YaST to do the setup, and referred to his two presentations from SHARE 104 for more information. David Boyes mentioned that the Samba HOWTO document on samba.org has a very detailed cookbook on the account migration aspect. Mike warned that the lmPasswd and ntPasswd fields are very important.

04/19/2005 - David Boyes noted that the Sine Nomine "tape mount daemon and some sample execs to label tapes for use with the ANSI/IBM SL support in Bacula 1.37 are now part of the Bacula distribution. If you've been holding off due to support from the Bacula team, now it's there...8-)"

04/20/2005 - Mark Post reported an article that talked about Resolvo Systems contributing its "MoveOver Windows-to-Linux migration tool" to the open source community. A Sourceforge project has been created as well. Mark noted that even though the tool was intended to be used to migrate desktop files, it might be possible to use it to move server data as well.

04/21/2005 - In response to a question about creating an installation directory structure from the multiple Red Hat Enterprise Linux 4.0 AS CD images, NoŽL Antonio said that the Red Hat instructions did mean exactly what they said: "You can't go wrong if you do as the guide says: (repeat for each CD-ROM):

  1. Insert CD-ROM
  2. mount /mnt/cdrom
  3. cp -a /mnt/cdrom/RedHat <target-directory> - where the <target-directory> is one single directory
He went on to say "If you just need basic services like web and ftp and don't need a lot of the development utilities, then 2.3GB will easily suffice."

04/21/2005 - In response to a question about creating a gcc cross-compiler for Linux/390, several people had some suggestions. Jochen Friedrich recommended reading the page at bytesex.org. Rob van der Heij said that he had good results from Kegel's crosstool. He warned that the "challenge is to get the runtime libraries at the right level with the proper patches to build against." Mark Post commented that the bytesex.org page had "cheated" by copying the glibc libraries from another source, and agreed that building those were very difficult. Carsten Otte said that the debian packages from debian.speedblue.org has worked nicely for him.

04/22/2005 - In response to what has become a common complaint when trying to install SLES9 systems, Jerry Whitteridge reported that the SLES9 FTP installation "requires a relative path. I had to specify ../../SLES9/INSTALLROOT in the ftp path instead of /SLES9/INSTALLROOT. After that everything worked OK -- it appears that the ftp server drops you into /home/&UID and that it uses that as the root for the FTP directories." Tom Duerbusch got essentially the same result by turning on the chroot option on his FTP server. He was then able to specify an absolute path instead of a relative one, since the FTP servers was then treating the home directory as "/" instead of "/path/to/homedir" The error that is reported when the path is not specified correctly is "Cannot read package data from installation media. Error no proposal."

04/22/2005 - A list member wanted to move a Linux/390 system from being a z/VM guest to running in an LPAR. Jim Sibley warned that if minidisks had been used for the guest's DASD that it would not work. In that case, data would have to be copied to new volumes before trying to IPL the system in the LPAR.

04/22/2005 - Robert Nix reported the resolution to a problem with communicating between DB2 systems on Linux/390 and z/OS that had been driving him crazy.

On roughly half the requests [from the Linux guest], Work Load Manager would route the request via XCF to the other half of the sysplex, which would process the request, and then send it.... Where? I[t] had no idea how to reach the source of the request, because the network the request came from existed only inside the CEC of the other half of the sysplex. Since it didn't know where to find the IP address, the response got thrown out to the defaultnet IP address. With some research, we figured out that it actually made it all the way back into the z/VM box. But the z/VM TCPIP stack had no idea that the hipersocket network existed either, and so it went to (you guessed it) the defaultnet address. Which bounced it back into z/VM. Which... Well, you get the picture.

Adding a route to the z/VM stack to route the request back into the Linux image completed the circle and allowed all the requests to be processed, but is not the optimal solution. I'm currently negotiating with our networking people to get a route put into the second z/OS to route things back across XCF to the hipersocket. At that point, I think things will be as optimal as I can get them.

04/28/2005 - Gerhard Hiller of IBM reported the following updates on the DeveloperWorks web site:

  • April 2004 stream
    • Kernel 2.6.5: Recommended kernel patch with bug fixes
  • June 2003 stream
    • Kernel 2.4.21: Recommended kernel patch with bug fixes
  • New OCOs for Red Hat
    • tape_3590 for Red Hat Enterprise Linux AS (v. 4) (31-bit and 64-bit) kernel 2.6.9-5.0.5.EL (2005-04-19)
    • tape_3590 for Red Hat Enterprise Linux AS (v. 3) (31-bit and 64-bit) kernel 2.4.21-27.0.4.EL (2005-04-22)

04/29/2005 - A list member wanted to verify that some new SLES9 installs had actually picked up the Service Pack 1 maintenance. Mike MacIsaac said that a "uname -a" command should show a kernel level of 2.6.5-7.97. Ihno Krumreich of SUSE recommended using the SPident command. He said that "SPident -v -v" will show information on which packages are at which service pack level.

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