07010551.txt 01-Jul-00


Subject: clipper and record locking
From: Ernst Sexauer <ernstsx@s.netic.de>

we are running a clipper-5.2 application with a novell-3.12
  server and 9 stations since 6 years. everything works
  fine.
now we have to change our server. we consider either
  linux/samba or nt-4.
first we have done some tests with record-locking on nt. it
  seems to us, nt is not locking an exact record as novell
  does, but an area around this record. we did not find
  documentation, how locking under nt really works.
we are going to run the same tests with linux/samba.
does anybody have experience with locking under linux/samba
  or nt?
is the advantage dbase-server available for linux or nt?

best regards
e.r. sexauer


Subject: Re: clipper and record locking
From: Arena <arenainformaticaNOarSPAM@zaz.com.br.invalid>

Hello Ernst

Excuse for asking, but if "everything works fine", why
  change it?
1) I recommend to consider also Netware 4.x/5.x. In our
  mixed development environment (Netware 4.11, NT 4.0 and
  Linux 6.2), Netware "wins" when dealing with DBF/ADS
  tables.
2) AFAIK, there's no ADS for Linux. For NW or NT it is an
  excellent product.

HTH
Marcos Nogueira


Subject: Re: clipper and record locking
From: Ernst Sexauer <ernstsx@s.netic.de>

i know, but the novell-server is running out of age and we
  need also internet-services. upgrade to novell-5.x would
  be very expensive. we are short of money and would prefer
  linux. linux provides all intra/internet-services we need.
what exactly does it mean, that novell wins? do linux and nt
  not work correctly or does novell simply perform better?
  performance is not our big issue - the application used to
  work on a 486-server quite well.

best regards and thank you for fast response
e.r. sexauer


Subject: Re: clipper and record locking
From: nick@nospam.demon.co.uk (Nick Ramsay)
So do what I & many of my clients do: stick to Netware for

  file / print serving & use a Linux box for email &
  intra/internet.  Why do you feel the need to load one
  server with every possible task?  It's always best to use
  the right tool for the job & this combination takes some
  beating.
>
what exactly does it mean, that novell wins? do linux and nt
  not work correctly or does novell simply perform better?
  performance is not our big issue - the application used to
  work on a486-server quite well.
<
Netware's file system performance & overall reliability is
  second to none, IMHO.  Samba works fine for Clipper apps
  if the data volumes and loads are fairly light, but
  Netware is more scalable & better suited to sharing DBF's
  without C/S.
Avoid NT for file-server duties if you are using Clipper
  without Advantage.  Even using Advantage, Novell will
  perform much better than NT on the same hardware.
Bottom line is: As Ernst says, why change something that is
  working for you when all you are really after is
  additional facilities - see my first paragraph...

HTH
Nick Ramsay


Subject: Re: clipper and record locking
From: Ernst Sexauer <esexauer@neuearbeit.de>

>
So do what I & many of my clients do: stick to Netware for
  file / print serving & use a Linux box for email &
  intra/internet.  Why do you feel the need to load one
  server with every possible task?  It's always best to use
  the right tool for the job & this combination takes some
  beating.
<
i would like to do so, but my client is short of money and
  can afford only one server. the update to novell-5.x is
  also too expensive. in addition, my clients company is
  giving up novell. this is policy. with linux i can build a
  separate inet-gateway as soon as an older workstation
  becomes available.
>
Netware's file system performance & overall reliability is
  second to none, IMHO.  Samba works fine for Clipper apps
  if the data volumes and loads are fairly light, but
  Netware is more scalable & better suited to sharing DBF's
  without C/S.
Avoid NT for file-server duties if you are using Clipper
  without Advantage.  Even using Advantage, Novell will
  perform much better than NT on the same hardware.
<
i would prefer to avoid nt at all, because i suspect the nt-
  record-locking. i made some tests on comparable machines.
  linux/samba performs about 2 times better than nt.


Subject: Re: clipper and record locking

From: Arena <arenainformaticaNOarSPAM@zaz.com.br.invalid>

Hello Nick

IMHO too. We maintain several networking OSs (both C/S and
  ptp) for development and support purposes. After the
  excitment of installing our first NT, we slowly began to
  realize that it wasn't "so superior", and - besides the
  server's GUI interface for administrative tasks - Netware
  could perform any job better.
Today we use NT only because some systems and databases
  require it.
To Ernst: don't think that Linux is cheap only because it's
  for free... As I've said in another post, be prepared for
  long sleepless nights if you need it to work properly.

Marcos Nogueira


Subject: Re: clipper and record locking
From: dev.nul@online.be (Luc Moesen)

Hi,

Have a look at:
http://www.cardbox.co.uk/ntserver.htm
PC Ext: Explanation of Opportunistic Locking on Windows NT
http://support.microsoft.com/support/kb/articles/q129/2/02.a
  sp
Over the past few months, several customers using Windows NT
  Server 4.0 and Workstation 4.0 have reported Index Out of
  Date errors or other data issues.  The culprit in most
  cases has turned out to be Opportunistic Locking, a
  feature within Windows NT that is enabled by default.  For
  those people using Windows NT, our preference is that you
  disable Opportunistic Locking on your Windows NT server
  and.
http://www.surehand.com/winCfg.htm


Subject: Re: clipper and record locking
From: "Tony Glynn" <tglynn@hotmail.com>

I agree with everything said so far. Novell servers provide
  superior performance on a dollar for dollar basis. I have
  no experience of Clipper under a Samba environment. I also
  agree with the statement 'There is no such thing as a
  cheap hard drive / motherboard / OS'
Clipper uses a record locking offset to allow programmers to
  lock a record yet still allow others to read the record.
  The offset was ( don't quote me here ) 2 GB with 5.01
  raised to 4 GB with 5.2. This means that when you lock a
  record the byte range locked is actually the offset + the
  number of bytes into the file + a record length. NT
  provides all programs with a 2 GB virtual address space.
  Its pretty tough on this as well. While the locking
  'appears' to work OK in actual fact is quite flaky. This
  leads to index and eventually file corruption. MS tried to
  fix the problem in NT 3.51 & early NT 4 but it was never
  entirely sucessful. They now refuse to acknowledge any

  input on the problem stating that Clipper is legacy
  technology.
If you do need NT then Advantage Server is by far the best
  way to go. If your client cannot stump up the cash for
  this or a Novell server then try to get them to calculate
  how they would function without the app.