Summary: Need comments on ClearCase (1/5)

Date: Wed Feb 05 1997 - 03:40:09 CST

Someone told me the first summary I post did not have the replies.
I was using a mail folder object in Xerox mail tool. It may not be working
very well with some other mail tools. I am sending it out again in a simple
mail note format.


The replies are experiences people face when using ClearCase in their own
environments. Opinions may be different because of factors like network
capacity, server capacity, available resources, number of users, SCM activities
profile, work load distribution, nature of projects, version of ClearCase in
use. We will encounter some issues highlighted in the replies due to the
nature of ClearCase, like the view, MVFS, and VOB locking while backup.
Other issues like network load, disk space increase are things we may face
and need to plan for.

A document at:

is a very good reference of configuring a work site to run with ClearCase.


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> 1. Any additional work needed in system admin? Percentage increae in

Better make REALLY good backups. You could see up to 20% increase work
load - support, backups, and cleaning up after users.

> 2. Hardware/resources requirements on Server, and Client stations.

Servers - get as much RAM as possible for VOB server, view servers need to
be REALLY good NFS server. The clients can be what-ever you have.

> 3. Increase in network traffic.

MVFS can be a PIG, read up on NFS trouble shooting. If you haven't
installed switching hubs (or better), do - check-in/out time and builds
can cause mass network bursts.

> 4. Any VOB backup/restore issue?

Haven't done it yet, but I have moved a few views (took along time).
When it comes to restoring a VOB - make sure you have a good backup.

> 5. Any file system management issue?

Make sure that users don't use Unix commands on views.

> 6. Others.

Paul Kanz
System Administrator
Interconnectix, Inc.
10220 SW Nimbus Ave, Building K4
Portland, OR 97223
Phone: 503.684.6641
Fax: 503.639.3469

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To: Boris <>
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From: Rich Casto <>
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>>>>> "Boris" == boris xssc <> writes:

    Boris> I would like to know what is the impact of using ClearCase:

I just finished evaluating ClearCase and we decided it wasn't right
for us. This was primarily because it seemed too complicated for the
size of our shop. We are a 15 person company with 10 developers, using
HP-UX and Solaris (and possibly NT in the future).

    Boris> 1. Any additional work needed in system admin?
    Boris> Percentage increase in workload?

There is definitely additional admin work, but I don't know how
much. It probably depends on how complicated your setup is. We decided
that it was going to be too much for us.

    Boris> 2. Hardware/resources requirements on Server, and Client stations.

This is documented in the manuals, which you get if you do a (free) evaluation.
(Btw, the CD-ROM has all the Unix and NT versions on 1 CD-ROM, which
is convenient. The Win 3.1 version is a separate product.)

    Boris> 3. Increase in network traffic.

Not sure, but since it uses NFS, there'll be some.

    Boris> 4. Any VOB backup/restore issue?

The manual says this is transparent, but we didn't investigate this.

    Boris> 5. Any file system management issue?

ClearCase creates a new file-system type, and in HP-UX 9.x actually
requires a kernel regen, so this has some impact.

    Boris> 6. Others.

The tech support via email was helpful (especially in helping me
locating some required kernel patches), but I was disappointed in
their response to some issues I had. For example, when I was doing the
HP-UX install, the manual said that this "may" require a reboot, but
what happened was that the install did a reboot WITHOUT any warning!
When I emailed the tech reps to report this, I got a canned statement
saying that they knew about it and were working on a fix for the next
release. This was sort of baffling, because the installation procedure
used a shell script that I'm sure they could have EASILY modified.

Also, I installed ClearCase on NT 4.0, but since they didn't have the
latest version (3.0) yet, I had to install a beta version of a 2.0
release that had a fix so it would work with a VOB on Unix. Then,
after it was installed, I started getting weird errors when trying to
login to NT. I had to do a hard reboot to fix the problem. Then I
ended up not being able to actually use it because I didn't have a
development environment (C++ or whatever) loaded! Also, the manual
said that you needed to login to an NT domain in order to access VOB's
on a Unix machine, but when I asked the tech support if I needed to
run NT server, they said no! This was wrong, as I pointed out to them,
because domains can only be setup when you're running NT server. (I'm
very new to NT, so I was surprised that I knew more about this than a
company that has a product running on NT!!) And you also need a PC
version of NFS to access VOB's on Unix.

I also found a few typos in the manuals that I thought were pretty

I hope this info was helpful.


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