SUMMARY: Solaris vs. Linux

Thank you to everybody for sharing your experience.

At first some statistics:
People think that Solaris is better: 11
People think that Linux is better: 4
People think that both OK, choose the one you have expertise with : 8

People think I'm trying to start a war: 3 .
 It's good that the list structure actually sends all replays to the one
asking question only ;)

Solaris pro
Stability
-Solaris seems to be more stable "out of the box" than Linux

Scalability
-Solaris is way more scaleable than Linux on servers with more than 2 CPU.
-Solaris ( especially Solaris 8 ) has VM and scheduler superior to Linux.
-Solaris TCP stack is better than Linux. Linux kernel 2.4 improved that, but
still can not beat Solaris.
-Solaris on Sparc is very good performance wise and does usually does most
of  "heavy lifting"

Manageability
-Solaris jumpstart installation saves big deal of time when manage a server
farm.
-Compatibility with enterprise applications (Oracle, WebLogics, Java,
etc...)
-Enterprise Tools - VxVM, Veritas Cluster Server, Sun Cluster, Netbackup,
Legato Networker, etc..  If you want to bring in a large vendor such as EMC,
Veritas, STK, ATL, whoever to interface their product with your machines
their people will likely know how to do it.
-Sun releases maintenance patches frequently . so maintaining the system
patch level is fairly simple.
-Solaris 8 got LxRun so it can run native Linux applications, but it's not
clear what the trade-offs are.

Solaris contra
-Solaris x86 software choice is quite limited.
-Solaris X86 hardware compatibility is limited, though most vendors have
certified hardware configurations.
-Solaris on X86 performance is not so good as on Sparc.

Linux pro

Performance
-Faster than Solaris on several 32 bit tests and under light load.  ( Faster
even than Sparc Solaris )
- the kernel is smaller and easier to streamline so performance (especially
on x86 machines for
   which they were written )

Stability
-You can get quite stable installation that will work for years if you get
right combination of  kernel/libc/gcc.

Fast development
- There are a lot of software for Linux . it would be better for developers
based on the supplied programs such as
   compilers etc. that come with linux distros
- Linux is, of course, far more "sexy and trendy" than Solaris; thus it has
a faster development cycle, has a much
   more "ragged bleeding edge "that changes very quickly (ie, new features,
bugfixes, etc are
   incorporated into the OS far faster!).


Linux contra:
Stability
- In order to get stable system right combination of  kernel/libc/gcc should
be chosen and it's not an easy and formal process.
- Linux is changing too fast to achieve degree of stability you can get with
Solaris.

Performance
- Linux multiprocessor support is not good in 2.2. It's way better in 2.4
kernel, but it's too new yet.
- Linux performance degrades faster under heavy load than Solaris.

Manageability and support
- Enterprise class databases support is not great.
- In many situations getting proper system patches is an art, not as simple
as download patch cluster from sun.
- Linux does not have truly commercial support.
- Linux upgrade/install  procedures usually are not tested well and may
corrupt your system.

Miscellaneous
- Bad NFS implementation. It's slow and doesn't work quite right, f.eg. file
locking does not work at all.
- Some basic services like YP don't work quite right.