General performance of linux vs. HP-UX

[Steve Lewis]

Hi,
Currently pondering R+D migration to Linux. Currently we are running our application (Informix) on L and N class under HP-UX 11.
What concerns me about Linux on cheaper hardware is the single PCI i/o bus. I know that Linux will run on HP9000 (L/N/RP????) Can anyone give me some indication of what the relative performance is between PCs and L class regarding i/o.
Any further indication of database performance under Linux (oracle or informix) would be appreciated. What about PC processors vs PA RISC. I am not so worried about the LAN since we use gigabit interfaces everywhere these days.

[Martin Burnett_2]

Hello Steve,

The ability to do research and development testing on Linux and then port it to HP-UX for production is why PA-Linux was developed. Specifically to be able to purchase cheaper hardware (still PA-Risc processors) like HP workstations, use free PA-Risc linux on the system and develop applications. The thought process being that (1) you are saving money by not having to purchase another server and (2)you are saving money by not having to purchase additional HP-UX licenses for your R&D machines.

However in your question it seems that you want to run the Linux on Intel based systems. This would not be a valid platform for R&D of applications destined to run on PA-Risc systems. The PA-Risc chips used in HP 9000 servers will not run programs you develop using Intel architecture. To say nothing of the issues you raise about other hardware compatibility issues (I/O, pci).

My suggestion is that you look at using possibly some older PA-Risc workstations/server that you already have and install PA-Linux (http://www.parisc-linux.org/) on them or look at purchasing a PA-Risc workstation from HP to develop on. By the way there are tons of used HP PA-Risc work stations on E-Bay for a ridiculously low price (I bought a C180 for $51.00) that I now have at home running 64 bit PA-Risc linux for an Apache web server.

Thanks for participating in the forums,

Martin
Chaos reigns within. Reflect, repent, and reboot. Order shall return.

[Krishna Prasad]

Hello Steve,

I agree with Martin. When comparing linux Intel 32bit based vs HP-UX Risc 64bit based is like comparing a Ford that we would buy at the dealership with the Ford's Jeff Burton, Mark Martin and the nascar boy's drive.

They are both Unix/Fords but underneath way to different.

[Alexander M. Ermes]

Hi there.
Just my 0.02 ??? to this. If you try to test Oracle database applications on Linux and then move it to HP-UX, you might just run into a wee bit of trouble. We have this problem with external developers doing testing and stuff on a Linux system, then move it to our N4000 machine. Oracle version is the same, but it is a real pain. We have to test everything on the HP-UX system again, before we can put it into action. Oracle 32-bit and Oracle 64-bit are a bit different.
As i said, just my two ct to this.
Rgds
Alexander M. Ermes

[Steve Lewis]

Thanks for your replies. Unfortunately you all misunderstood my question completely.

It was never my intention to program on LIntel and attempt to then run on HP-UX. That would be a stupid idea and I am far to experienced to even consider it.

I am tasked with finding ways to reduce costs of the whole installation. This may involve completely ditching HP-UX and HP9000. What we like about HP at the moment is the superb software and hardware support, together with the awesome reliability of the kit.

It may be possible, however, while slowly migrating applications to a multi-tier model, to run the database on Linux, while keeping the existing applications on HP-UX, thus removing the problems of porting 1000000+ lines of code to a new o/s and using proven database interfaces that are not o/s specific. Also new code (vanilla Java) is less platform specific than C.

Is it going to be a false economy?

It looks as if I will have to do some performance tests after all.

[Kodjo Agbenu · Accepted solution]

Hello Steve,

First of all, considering that HP9000/HP-UX platforms have been running database applications for years, of course this is the more reliable solution. Moreover, there are 2 big problems with intel/i386 platforms :

-> The hardware is cheap, therefore often not so reliable as proprietary hardware like HP9000, RS6000, SPARC...

-> The hardware changes very often. For example : the N-class was introduced late 1999, and it is still on the market. The Netserver range of products is renewed every 18 months.

Then, let's talk about Linux : from my own experience, I would say : don't be afraid about Linux. It will run most of your applications with very good performances.
Of course if you have a 200GB database with 2000 simultaneously connected users, it would be a better idea to go with HP-UX.

What about performances ?

=> CPU : if you run CPU-intensive applications on machines with 1 or 2 processors, you would probably have more performances with Intel P4 and Linux. However, if you have heavy load (many many processes running at the same time), HP-UX would probably give better results.

Database applications are not CPU-intensive. In some cases, big batch processing require powerful CPUs. If you are in this case, I suggest you do benchmarks before changing your architecture.

=> I/O : in N-class datasheet, you can read something like "4.3 GB/sec i/o throughput". Even with the best Netserver, the i/o bandwidth does not exceed 2.5GB/sec.
However, talking about small machines : L1000 cannot exceed 1.3 GB/sec, which is less than the i/o throughput of a Visualize Workstation (often 2GB/sec).

Here, unless you have I/O intensive applications (datawarehouse, big batches), you can safely go with Linux.


To summarize : Linux may be OK in most of the cases, but if you have i/o or CPU intensive applications, do some sizing and even benchmarks before.

good luck.

Kodjo