Clearcase Problems with Linux?

joecooler asks: "I work for an ASIC company in the verification group. We use VCS and Vera to write and run simulations, Clearcase for revision control, and LSF to manage our server farm. At my instigation my employer has begun to move to Linux PC's for our simulation server farm instead of the much more expensive and much slower Solaris Sun machines. Everything has been working well and everyone has been very pleased with the performance except for one 'small' problem - every two weeks or so we will suddenly see all jobs running on Linux machines crash. After much pain we have been able to isolate this to an issue with Clearcase returning files 'slowly' to the Linux machines, causing VCS compiles to die. Has anyone else had issues with Clearcase and Linux running on a PC? If so, how did you debug this and isolate the exact source of the problem? Is this solvable, or is it one of the mysteries of networking?"

Comments

What's with all the custom kernel crap?

[renehollan]

Back in the day, when I used Clearcase with Linux (c. 1999-2001), our Sun boxes were set up to make Clearcase views visible as NFS-mounted directories. No shmancy proprietary MVFS-hacked Linux. We used Multisite without any problems, either.

Now, it's true that one had to handle checkins and checkouts from a Sun box, but, as the build farms mounted the exported views read-only, what's the big deal? Is it really necessary to integrate the source control system that tightly with the Linux-based development environment?

Re:Curious

[Outland Traveller]

The main difference is that we sell a "turn-key solution". It's a black box destined to go straight to end users who don't interact with the OS directly and in 99% of cases don't want to even know whether Linux is under the hood or Windows, or Solaris, etc, so long as box does what it is supposed to do. Of course a super power user could get into the OS and run other applications and scripts- unlike some other vendors we make it relatively easy to do that.

We provide a customized kernel that includes the most up to date drivers for the periphrials the box needs to talk with, some of which are esoteric. We also do some performance tuning and add some publicly available security patches.

I believe what we do is fundamentally different from what Rational does. We're selling a black box solution that solves one particularly complex problem. That's what our customers want, and there is no expectation that the customer will be able to run other applications on the platform, never mind use a different kernel. The product includes hardware and software maintenance that keeps the system up to date and secure, so it's important for maintenance purposes that we keep the system configuration under tight control.

Rational sells a software development tool. The expectation is that the end user will be running the client on the development system, which presupposes a wide variety of both hardware and software, depending on whatever the customer wants to develop. When rational ties their product to a small subset of Linux kernels, they dramatically limit what kinds of development you can do, which is not a particularly competitive thing to do. Worse, their supported kernels do not keep pace with security patches or major driver bugs (like the ext3 bug in redhat's initial 7.3 kernel release).

Hope that clears it up..