Review: Linux distro sets high virtualization expectations but falls short
With its Corporate Server 4, Mandriva is challenging the Linux data center operating systems from Red Hat and Novell by offering broader support for virtualization technologies. Its a solid-sounding plan, but eWeek Labs tests of CS 4 show that its longer on ambition than execution.
Mandrivas CS 4 is unique in its support for three different virtualization frameworks: Xen, OpenVZ and VMware. However, CS 4 not only fails to advance the state of these frameworks on Linux, but, where Xen is concerned, CS 4 falls short of the implementations now offered from Novell and Red Hat.
The Linux operating system offerings from Mandriva (the company formerly known as Mandrakesoft) have historically been recognized for their newbie-friendliness and their knack for giving usersprimarily desktop usersaccess to software components not readily available from bigger companies. Indeed, the French companys initial raison dêtre was to offer users a Red Hat Linux clone with the graphical K Desktop Environment that Red Hat, at the time, didnt distribute.
Component flexibility remains a key selling point for CS 4, which Mandriva began shipping in September. Sites with a satisfactory service and support relationship with Mandriva should take CS 4 for a spin to see whether the upgrade is worth undertaking.
However, administrators looking to deploy specific virtualization platforms on Linux should consider alternatives that have proved themselves in eWeek Labs tests.
Those interested in deploying a Xen-savvy Linux distribution, for example, would probably be better off with Novells SLES (SUSE Linux Enterprise Server) 10, which implements Xen. (See "SLES 10 pairs well with Xen" at eweek.com.) Based on our tests, Novells Xen efforts are more mature than those of Mandriva. Another Xen option worth investigating is XenSources XenEnterprise 3.0, which, so far, is the best Xen implementation weve tested. (See "XenEnterprise 3.0 works well within limits" at eweek.com.)
Companies interested in deploying OpenVZ virtualization can give CS 4 a try, but we much prefer Debian GNU/Linux, which also offers OpenVZ-capable kernels.
Administrators interested in pursuing VMwares virtualization platforms may already be halfway there, as the companys offerings run on a wide-ranging list of host operating systemsfrom Windows to a handful of prominent Linux distributions, including free and fee-based options.
Mandriva CS 4 sells for $314, $414 or $654 with one, three or five years of maintenance support, respectively. Mandriva CS 4 supports x86 and x86-64 processor architectures. eWeek Labs tested the 64-bit version on a single-processor Advanced Micro Devices Opteron system with 2GB of RAM.
It was the promise of virtualization flexibility that piqued our interest in Mandrivas CS 4, so it was disappointing to find that Mandrivas integration efforts arent that far along.
To begin with, no VMware packages came along with CS 4, which is available for a one-month free trial from my.mandriva.com/cs4/trial. According to a Mandriva support representative, VMware packages are slated to become available soon through the CS 4 update channel.
The representative added that the VMware packages available directly from VMware would run fine on CS 4. Weve had success running VMware Workstation, Server and Player on a wide range of Linux hostsboth explicitly supported and notso we dont doubt that the software runs just fine on CS 4. But thats not the point. What we hope to see from Mandriva, in addition to an option to install VMware Server through the distributions network repositories, is the availability of VMware drivers compiled to match the Mandriva kerneland subsequent kernel updates.
Without this driver availability, administrators must compile VMware drivers themselvesa relatively easy task, but one that requires that an otherwise superfluous compiler and associated tool set be installed on the VMware Server host.
Another CS 4 virtualization option is OpenVZ, the open-source variant of SWsofts Virtuozzo product thats similar in architecture to Sun Microsystems Solaris Containers feature.
CS 4 ships with kernels that include the OpenVZ patch set. OpenVZ is not yet part of the mainstream Linux kernel, so theres a definite value in Mandriva including the patch set. However, Mandriva doesnt appear to have taken any steps to further integrate OpenVZ into CS 4, and the distributions documentation makes no mention of OpenVZ. Rather, Mandriva support personnel directed us to the documentation available from the OpenVZ project site.
Mandriva needs to provide setup and management tools and CS 4-specific documentation for OpenVZ before well consider the technology an integrated part of the product.
Xen also is currently absent from the mainstream Linux kernel, so its nice to see that CS 4 provides a Xen-enabled kernel as well as documentation for setting up Xen virtual machines. However, Mandrivas Xen implementation lags well behind whats available with other distributions.
For example, when we first tested Xen on Red Hat Fedora Core and Novell SUSE distros, we were required to work around a compatibility issue between Xen and Linuxs TLS (Thread Local Storage) libraries: We had to move /lib/tls to /lib/tls.disabled, lest we suffer reduced performance under a Xen-enabled kernel. In recent Fedora and SUSE versions, this hack is no longer necessary, but CS 4s documentation asked us to fiddle again with /lib/tls.
We did disable TLS as asked during tests, but we still experienced an overall slowdown. We tried disabling /lib64/tls, since we were running CS 4 on a 64-bit system, but this step rendered CS 4s RPM (RedHat Package Manager) unusable, so we had to reverse it.
Mandriva would do well to look into the Xen solutions that Red Hat and SUSE have pursued and integrate them into CS 4after all, Red Hat and SUSEs work is open-source and freely available to Mandriva for copying.
For system management and configuration tasks, CS 4 offers administrators three different tool sets. Together, the tool sets cover most administration needs, but they would benefit from being better integrated with one another.
CS 4s tools for software management, basic hardware configuration, network settings, mount points, security, boot loader configuration and miscellaneous other tasks are collected in the Mandriva Control Center, which more or less resembles SUSEs Yast tool set but with fewer modules.
New in CS 4 is another, separate tool called FIBRIC (First Boot RPM Installer and Configurator). After we installed CS 4, the Web-based FIBRIC presented us with a list of roles that the CS 4 system could carry out. For instance, FIBRIC listed an Identity Server role and offered to satisfy this role by installing an LDAP server, a Kerberos server or both.
We liked the roles-based installation options, but we were concerned that FIBRICs Web interface didnt provide SSL (Secure Sockets Layer) encryptionparticularly given that FIBRIC required our root password to operate. In addition, the configuration options that FIBRIC offered for the services we installed were rather thin.
This brings us to CS 4s third independent management tool set, courtesy of the open-source Webmin project (webmin.com). Webmin is a Web-based interface for system administration tasks on Linux and Unix, with Webmin modules available for handling most configuration tasks. Although Webmin isnt the default administration tool for any major Linux distribution of which were aware, packages for the project are available for most distros. Wed like to see Mandriva more tightly embrace Webmin.
At the time of our review, Mandrivas hardware compatibility database did not include information on CS 4. For the previous release of the distro, CS 3, there were seven x86-64 servers and 14 x86 servers listed as certified.
Advanced Technologies Analyst Jason Brooks can be reached at firstname.lastname@example.org
Microsofts Windows Server 2003
Offers good software support, rather approachable management tools, and virtualization options that include multiple free and for-fee options (www.microsoft.com
Novells SLES 10 and Red Hats RHEL (Red Hat Enterprise Linux) 4
Both distros enjoy broader independent software and hardware vendor and processor architecture support than CS 4, and the SLES Xen implementation is more mature, to boot (www.redhat.com
Suns Solaris 10
Sports very good virtualization support through its Containers feature, along with good x86-64 support (www.sun.com