Posts Tagged ‘Linux’

Epson scanners on Linux systems

Tuesday, January 11th, 2011

I’ve got a Epson Perfection 1260 Photo scanner.

Fedora like other distributions such as OpenSuse are recognizing the device since a long long time. The back end chosen for the device is plustek.

Unfortunately when using the default configuration one experience very strange effects with colours. The left and the right 50% of the picture have a colored background, even when scanning a empty page.

I had this problem with OpenSUSE since years and still got it with Fedora 1x. Since I only need the scanner for my yearly income tax declaration, I always forget about what I needed to change.

That’s what is needed to change:

Solution

[root@bond ~]# diff /etc/sane.d/plustek.conf.orig /etc/sane.d/plustek.conf
100c100
< option altCalibration 0
---
> option altCalibration 1
[root@bond ~]# 

Since I do not have any other scanners I do not know if this is a bug specifically to this type of scanners, or if it is a general bug.

Using different search engines, the web does not disclose some solutions. That is one of the reasons why I’m blogging about it. The other reason is to find other people with the same problem.

At the end of the day, I’ll try to find out if this is a general bug of the Sane back end, or just specific to some Epson scanners. If it is specific to some Epson scanners, it may be worth to create a new specific back end for those scanners affected.

Having fun? Now I have, my stuff is successfully scanned.

Usability Fedora vs Windows

Tuesday, November 30th, 2010

I’m writing this post sitting in a train, connected to the internet via UMTS. The device is a Huawai E220 HSDPA modem connected via USB. Guess who is the winner?

Procedure to get the device running on Fedora (first time usage):

  • Plug in the device on any USB port
  • Enter the PIN in the pop-up
  • Enjoy mobile Internet connection

Steps: 3
Time: approx. 5sec.

Procedure on Windows XP (first time usage):

  • Decide on what USB port you will plug in the device an memorize it, because subsequently it will only work on that USB port
  • Plug in the device
  • A virtual CDROM drive gets mounted, a window with some drivers is appearing
  • Install the driver
  • reboot your notebook
  • Finding and starting the previously installed software
  • Getting a pop-up asking for the PIN
  • Enjoy mobile Internet connection

Steps: 8
Time: approx 10min

[update]
Procedure on Windows 7 (first time usage):

  • Decide on what USB port you will plug in the device an memorize it, because subsequently it will only work on that USB port
  • Plug in the device
  • A virtual CDROM drive gets mounted, a window with some drivers is appearing
  • When autorun.inf is enabled, the driver installs automatically (on enterprise systems mostly disabled). if not enabled, read some documentation what to do
  • Finding and starting the previously installed software
  • Getting a pop-up asking for the PIN
  • Enjoy mobile Internet connection

Steps: 7
Time: Between 5min and 30min (depending on your Windows 7 knowledge)
[/update]

For the subsequent usage on Fedora proceed as it is the first time usage.

On Windows (XP and 7) you need to remember which port you plugged in the device when you installed it. Otherwise you need to uninstall the drivers, reboot and install the drivers again and reboot again. [update]On Windows 7 you do not need a reboot.[/update]

Having fun? With Fedora yes :-) With Windows? Not really…

Deploying RHEL as ESX guests – Kickstarting or using ESX templates?

Wednesday, October 20th, 2010

Some time ago I asked my self the question if it is better to kickstart systems or working with ESX templates when deploying RHEL as ESX guests. I also had some discussions with friends working in the same industry. I tried it and came to the following conclusion:

Kickstart the systems is the way to go.

Pros:

  • Kickstarted Systems are already up-to-date after installation.
  • Proper SSH host keys. Using ESX templates ends up in having identical SSH host keys, from the security standpoint not usable, they need to be manually re-created.
  • Kickstarting means lean deployment, much less data needs to be transferred.
  • Very fast, kickstarted systems are deployed in ~3min instead of ~10min (depending on I/O and network performance).
  • Systems are being automatically registered @rhn or on a rhn-satellite with the help of cobbler snippets.
  • Better customization.

Cons:

  • The ESX template to used for kickstarting must have no disks configured, otherwise the whole nominal disk size is being transferred over the net.

When kickstarting virtual systems, only the data needed (the RPMs) is transferred. The best way is to have a “empty” ESX template, just with the network defined, but no disks. The reason for that is: ESX creates a checksum of the disk files, even if the disk is empty, the sparse disk files (in the case of “thin provisioning”) will be transferred over the net at its full nominal size.

When using ESX templates, after deploying, one needs to register the system manually and also manually update the system by invoking “yum -y update”. In contrary, kickstarted systems are always up to date automatically. To circumvent this fact, one needs to keep the templates up to date, it is a manual task which can not be automated easily.

Have fun!

RHN Inter-Satellite-Sync is kind of tricky and picky

Wednesday, May 5th, 2010

If you try to establish an ISS (Inter Satellite Sync) between two RHN Satellites, do not fully trust the documentation. A slave Satellite must be named by a hostname (IP is not enough) and must have an A and a PTR DNS record or have an /etc/hosts entry. Check it before restarting the satellite by issuing rhn-satellite restart. The check is simply done by entering gethostip rhn.example.com and getent hosts <IP-address> on the commandline.

When Quoting the documentaion at Red Hats web site: http://www.redhat.com/docs/en-US/Red_Hat_Network_Satellite/5.3/Installation_Guide/html/s2-sync-iss-config-master.html: allowed_iss_slaves=rhn.example.com means: A hostname, not just an IP. It is not clearly stated what kind of quality such an entry needs to have.

HTH….

Have fun!

Spacewalk 1.0 released

Sunday, May 2nd, 2010

spacewalk-1-0-release

Spacewalk 1.0 has been released

Spacewalk is the upstream project for Red Hat’s RHN Satellite software, one of the best systems management software available for Linux Systems.

In the past few weeks one could see a lot of git commits on the source repository of spacewalk. There is no changelog available yet. The road map mentioned compatibility with Apache Tomcat 6.0.x to be able to install spacewalk on Fedora12 and RHEL6.

There should have also been several enhancements in the phyton API and long awaited feature enhancements such as host-renaming (confirmed). Further repository synchronization should be much faster now (Announced in a earlier feature note).

Sorry folks, a lot of “should”, “maybe” etc. I just have been reading the git commit logs and the announcement of the 1.0 release. As long as there is not official changelog available we only can speculate on the precise enhancements.

I’ll install this on my test system soon. If something really uncommon happens or an astonishing new feature appeared, I’ll let you know,

Have fun!

Ubuntu 10.04 LTS released

Sunday, May 2nd, 2010

End of April 2010, Ubuntu 10.04 was released. As always it is based on Debian’s Testing-Release. Canonical “stabilizes” the testing tree of Debian and adds its own look.

This time, Ubuntu radically changed its look. From my point of view it looks ugly, very ugly. Strange colors, low contrasts in menus, orange icons in Nautilus… window buttons on the left side… At the end of the day an usability-horror.

Under the hood Ubuntu is a very stable distribution with recent software. Ubuntu 10.04 is a LTS (Long Term Support) version and is thus suited as a enterprise server. Support for the server variant of Ubuntu is five years. Ubuntu is – like Debian – capable to upgrade to a new major release w/o service interruption.

Managebility

You “can” mirror Debian and Ubuntu repositories locally but it is difficult if you to not like to mirror all architectures available. Unfortunately there is (AFAIK) no software available such as Spacewalk/RHN Satellite to manage your servers.

The best method is to allow each single system installed to talk directly or via proxy to the mirror servers. This is a nightmare for firewall administrators.

To my knowledge there is no convenient way to install Ubuntu over the net. There are rumors that spacewalk and cobbler is going to get Debian/Ubuntu support at some time.

Reliability

Debian and thus Ubuntu has an evidence to be reliable. This also  seems to be true for the current release 10.04. The software came from Debians testing repository but was stabilized during months. Canonical (The sponsor of Ubuntu) has a reputation for its quality management. To use Ubuntu as a server operating system is sane.

Conclusion

As a desktop operating system I’ll avoid Ubuntu, since the usability is focused on dummy-users and not professional Linux users. For server usage you need to ask yourself about your needs. If you are operating Oracle DB’s or other commercial applications you probably want install Red Hat Enterprise Linux (RHEL). For a web server Ununtu is very well suited, even better than RHEL. In two years there will be another LTS variant available and you are free to upgrade online. Reliability is very good, manageability is poor, especially when used in larger companies.

In short: Ubuntu for web servers, RHEL/CentOS for other servers.

As always: Feedback is welcome…

Have fun!

A brief test of RHEL 6 Beta 1

Friday, April 23rd, 2010

As promised yesterday, I publish the results of a brief test of RHEL6 Beta 1 and the most important findings. It is my point of view as a system guys daily business. If not stated, this overview is based on a default installation with no customization.

General

  • There are new package groups such as  “Minimal” with 228 Packages and “Basic Server” with 523 Packages. “Basic Server” is the default installation, which means the default click trough installation compared to RHEL5 is much less bloated.
  • The versions of the most important software is quite up-to-date but as expected not on the bleeding edge.
  • Postfix is the default MTA. Finally Red Hat managed to switch away from sendmail like other distributions did it years ago.
  • Bye bye SysV init: As I guesstimated in october 2009 RHEL6 comes with upstart instead of traditional SysV init. (See http://blog.delouw.ch/2009/10/31/ready-to-upstart/). The boot process is much faster compared to RHEL5. Upstart comes with legacy support for traditional runcontrol scripts in /etc/init.d.
  • Still too many services enabled after default install. Generally unneeded services like avahi/mDNS and NFS-related daemons such as  portmap are still enabled by default.

Virtualization

As expected, Xen was removed completely from RHEL6. These is being discussed controversial. Why not providing both virtualization solutions as before? Recently Citrix released Xen4 which works well together with Kernel 2.6.32, the same version as used by RHEL6.

KVM and its friends made a huge step forward. lib-virt, virt-manager and stuff is nearly up-to-date with the upstream versions. Means: The virtualization infrastructure made a lot of progress. Installing RHEL6 as a KVM guest works great. All drivers needed (virtio) are automatically installed.

A major good message to people which are using VMware vPhere 4 is that RHEL 6 comes which native support of vmxnet3 which was obviously backported from Kernel 2.6.33. Vmxnet3 is the driver for VMware’s para-virt NIC which brings quite some performance enhancements and lower CPU usage on the ESX host.

Certifications from ISVs

A quick check (not actually tested) for the requirements for SAP and Oracle shows that those are fulfilled already. We can expect the certification quite soon after GA of RHEL6. [update] Some compatibility RPMs from the mid 1990′s disappeared.  I now need to figure out if they are *really* needed by Oracle and/or SAP[/update]

Integration with Cobbler

Integration with cobbler works like expected, cobbler import –path=/mnt –name=rhel6 and you are done. For a quick test I just copied the kickstart template from RHEL5 and I’m not sure if this is a good method. A test-install on ESX4 failed, the system hung at the creating of the root-VG. Not sure yet if it is a bug or something is incompatible in the kickstart. [update] The system hung was because of out-of-memory. The test-installation was on a ESX guest with 384Mbyte of memory which is enough according to the documentation but too little in real life. Growing the RAM of the test system to 512Mybte helped, but some packages needed by for SAP have changes names or disappeared.  After changing/removing those RPMs, the installation went smoothly[/update]

Bugs or features?

I detected some oddities where I’m not sure if it is a bug or a feature. We will see whats going on on http://bugzilla.redhat.com.

  • No network configured after default install. At the moment you need to configure it manually (considered a Bug)
  • I detected a major security issue during install, I’m not going to disclose it before a patch is available or more information from Red Hat is made available. I reported it 2010-04-23 ~12:00 on Red Hats bugzilla bugtracker. [update] The bug gots assigned to a Red Engineer after three hours, seems like Red Hat is acting very professional on the case[/update]

Conclusion

After this brief test one can say that RHEL6 will be a really great Linux Distribution for enterprise servers. The beta is already very stable with few bugs detected from my side. My guesstimate is that mid of May 2010 there will be a second public beta released, lets stay tuned, I’ll keep you up-to-date with further findings.

Have fun!

RHEL 6 public beta released

Thursday, April 22nd, 2010

Red announced the first public beta release of its next Enterprise Linux.

It can be downloaded at Red Hats FTP Server.

You can expect a brief test later this day.

Roadmaps on the Red Hat Summit 2010 in Boston

Monday, March 15th, 2010

Finally Red Hat disclosed the agenda of its summit in 2010. For more informations see http://www.redhat.com/promo/summit/2010/agenda/.

RHEL6?

Tim Burke of Red Hat will talk about the new features of RHEL6. It sounds like the present, not the future. Does this mean I’m right with my guess that RHEL6 will be released end of June like I wrote in earlier blog article?

Roadmaps

Count how many times the word “Roadmap” appears in the agenda. It seems to get even more interesting what Red Hat plans to do. But it is still unsure what kind of new features we can expect in RHEL6. Red Hat just disclosed some snippets of RHEL6 again, this is called Salami-Tactic.

Where is the commitment?

We (the RHEL community) are still missing a clear commitment to us as customers. Only little is known about RHEL 6

Love or hate?

Should the RHEL community love or hate Red Hat? At the end of the day I like Red Hat, they do a lot for the progress of Linux in general and Linux in enterprises in particular. Anyway: Not providing a roadmap makes me and possibly others too very angry. Such a roadmap does not need to necessarily be in detail.

Have fun! Really? Soon we will have!

Kernel questions about RHEL6, ESX support and experiences with F13a3

Monday, March 15th, 2010

Still no official informations

Red Hat is still refusing any questions about the features of RHEL 6 and its Linux Kernel. However: Since Vanilla Kernel 2.6.33 vmxnet3 and pvscsi is supported. Fedora 13 Alpha 3 is shipped with a derivate of Kernel 2.6.33.

I still hope that Red Hat is switching to 2.6.33 or back-porting the VMWare code to its 2.6.32 derivative Kernel as known by RHEL 6 Alpha 3.

Experiences with F13a3 so far

Installing F13a3 on a ESX guest – with RHEL5 as “supported Guest OS”  – and enabled vmxnet “enhanced” plus pvscsci as HBA was a smooth experience. No driver disk was needed, no dirty fixes. Just selecting vmxnet3 as NIC and PVSCSCI as disk HBA. Thats the way RHEL6 should work from my point of view.

RHEV vs. VMWare ESX

Since Red Hat released its visualization solution “RHEV”, VMWare and Red Hat are competitors. Is Red Hat willing to include ESX support in its Enterprise Products? My guess is to not to do so, but I’m open for surprises.

The goals

The goal on the long term is to switch from ESX to KVM. However, if you deployed a large ESX farm already and the management members are members of the “ESX-Church” it will be hard.

The mid-term goal is to get rid of those crappy VMWare tools. The current state of this “Tools” definitively proves that VMWare is a Windows shop and  does not take care about Linux virtualization.

Will we have fun? Depends on EMC and Red Hat….