With the newest release of The SCO Group's UnixWare, it could be said that this variety of Unix is starting to look a lot more like Linux - even if SCO lawyers pulled the Linux Kernel Personality modules from the operating system during the course of our testing.

We tested UnixWare 7.1.4 with both new management components and added open source applications to compare it with Linux and Apple OS/X operating systems we've tested recently.

The results were mixed. UnixWare did well in our Web connectivity and performance tests, but wasn't as advanced as its Linux rivals in terms of its GUI and hardware discovery facilities.

Up to running
We installed the Enterprise Edition of UnixWare on four different server platforms. The initial installation was primitive compared with UnixWare's Linux rivals SuSE and Mandrake. No installation GUI was invoked, just coloured text graphics. Hardware detection also seemed a difficult task for UnixWare. As an example, UnixWare could not correctly find a KVM-attached mouse. To bring up the first instance of the operating system, we had to plug a mouse directly to each server.

A common platform, the HP/Compaq DL360G3 server presented other problems for the installation application, which consistently could not find the CD-ROM drive on the server midway through installation. SCO support advised a boot-time toggle that let the drive successfully work through installation; however, installation time slowed to a crawl - more than 90 minutes per CD installed. The installation program found multi-CPU configurations correctly and offered optimization options for the multi-CPU chipsets it found.

We subsequently downloaded the operating system to other servers using the "TCP" (actually PXE server) installation option that immensely speeds up installation to multiple servers.

The SCO Update service (not tested, as no updates had been issued at the time we tested) connects to the host for updates from the mothership.

Installation options are plentiful. Two popular versions of Apache are available - 1.3 and 2.0.49. We tested the latter of the Apache Web services (including Apache Tomcat). Other open source applications are available, such as Samba 3.0.3, which provides connectivity to Windows directory services. Also available is SCO's older Advanced File and Print Services that support pre-Windows 2000, DOS-based Windows clients.

Four levels of security are available, ranging from basic to "above C2" (a US government certification for certain types of security hardening and password functionality). Instructions state that increasing the security level above that chosen at installation is not possible. But it is possible to downgrade security if needed. We chose the highest grade for all our tests and found that we needed to lower the security to enable certain functions such as Secure Sockets Layer and Secure Shell Version 3 connectivity.

We used Internet Security Systems' Security Scanner 7.0 to find vulnerabilities in UnixWare when it was running in both C2 and "above C2" modes. Both selections passed muster with no vulnerabilities found.

SCOAdmin is an X-Windows-based management interface that administrates server characteristics (hardware and network) and user accounts and OpenLDAP settings. SCOAdmin uses a tree-like menu system, and we found administration simple, if superficial, as some applications (such as Dynamic Host Configuration Protocol setup) lack needed options such as DHCP forward referencing.

Windows emulation, provided by SCO's neTraverse Merge 5.3 in UnixWare, supports Windows 3.1 to Windows Millennium applications. Windows NT-specific applications running under neTraverse usually don't work well, and emulation can load down the CPU(s). An installation of Windows Office 2000 failed, and use of Windows Office 97 ran unacceptably high CPU utilisation.

The Rendezvous protocol, which can be used to find printers and other devices, isn't supported, but the Common Unix Printing System is supported, and we found our Lexmark 710 network printer by adding its IP address. Apple connectivity via Apple Filing Protocol wasn't natively supported, and we used Apple network connections via Samba connectivity.

Performance
This is the first time we've run our Spirent Communications WebAvalanche tests on the dual CPU Compaq DL-360G3. While we can't make a direct apples-to-apples correlation between SCO's results and past operating system tests run on four-way machines, we can deem UnixWare a strong performer overall.

For example, in our transactions-per-second test, which manipulates static pages, UnixWare completed 704 transaction/sec on average, which is 75 per cent faster than the dual-PowerPC CPU Mac Xserve running OS/X 10.3. The best numbers and worst numbers on a four-CPU platform were 1,204 and 994, respectively.

The maximum number of open TCP connections UnixWare could sustain was 54,208, which is higher than the previously tested Apple combination. This began to approach all other operating systems running on four-way machines that tally open TCP connection rates between 68,000 and 87,000 maximum open TCP connections.

In our maximum TCP connections per second test, UnixWare could maintain 972 connections to Apple's 616, but fell down by comparison to SuSE Linux and Windows 2003 Enterprise Server on the four-CPU platform. The implication here is that Apache runs quickly on UnixWare and the network subsystem can sustain many option connections but doesn't connect and release connections quite as quickly as the competition.

Hardware driver selection also had a strong bearing on file I/O performance. Once we'd changed the UnixWare-picked disk driver for the HP/Compaq DL360G3, we achieved strong single-drive and inter-drive performance at 65M-bit/sec single and 68M-bit/sec inter-drive. UnixWare also has emergency recovery support for Integrated Drive Electronics, SCSI and certain removable drives, but this feature wasn't tested.

OUR VERDICT

We found UnixWare to have an applications list that's comparable to its Linux peers and Apple's latest server operating system. But overall, the Linux systems tested know the underlying hardware better and present a GUI more readily than UnixWare. Additionally, while UnixWare is a decent performer, UnixWare could have tighter ties with its open source add-ins.