[Technical] Sonasoft?

[Clark, Ian C]

> -----Original Message-----
> From: tech-bounces at edulists.com.au [mailto:tech-
> > You mean your company developed this product without understanding
> the
> > concept of file locks?
> 
> No, as a coder who started on CP/M, I know the concept of enforced
file
> locks for general purpose apps. What _I'm_ asking is why are they
still
> necessary in 2006?

Then you still don't understand them. 

Any area of computing that has transactions (and it can be kernel
processes or a web database) needs concurrency control.

The most advanced programming environments are Java and .Net - they're
much newer than CP/M, and both support read and read-write file locking.


> Linux shows that you can have a functional OS without needed to
enforce
> 'genuine' file locking

Did you read the article in the link I posted?

It's a weakness that has caused some to go their own way ... as the
article says,  "the cooperative locking approach can lead to problems
when a process writes to a file without obeying file locks set by other
processes. For this reason, some UNIX and UNIX-like operating systems
support mandatory locking as well."

> > File locks are genuine in Windows, not advisory as in Unix ... a bit
> > like voluntary traffic lights at an intersection!
> 
> And they are needed for what reason?

To stop the interceding update problem!

> > > and you don't need special 'shims' to work around backup issues
> with
> > > Microsoft's SQL Server and Exchange.
> >
> > And Oracle, and DB2, and GroupWise, and Notes, and ... you get the
> > picture ... no point demonizing Micro$oft for *their* enterprise
> > database or collaboration system ...
> 
> And yet, these aren't needed for MySQL, PostreSQL etc. 

Of course they are! You can't just backup MySQL or PostgreSQL by copying
the directories to your Cybersource "Datasafe" server! The archives can
end up corrupted!

What if several records are halfway through being updated when the copy
is made? 

What if the hard drive hasn't yet committed some writes to the database
from its cache yet?

You need to use a shim like the mysqldump tool, or you need to lock and
flush the tables first before doing a file level copy or shut down MySQL
or PostgreSQL altogether!

> Perhaps, NTbackup is free.
> 
> But add the costs of 3 * server hardware, 3 * Win2k3 server licences,
3
> * CALs & 3 *installation and you get the picture. For 25 users, that's
> $30k.
> 
> Do the costings and get back to me if you can get a cheaper quote ;-)

For 25 users, I couldn't recommend to clients your three server, $10,000
solution that can't back up open files.

I would go with either:

1) a single Win2k3 Small Business Server, say, from Dell. Hardware RAID
for system, swap, programs and data partitions, and either removable USB
disks or a tape drive so that backups can actually be taken offsite, so
that when a fire hits the office and wipes out your "Datasafe" backup
solution, the data is actually safe. With all the inbuilt wizards I'd be
happy to go with a fixed price eight hour labour on the setup of server
and client connections - $3000 plus $1000 equals $4000 total. $130 for
each CAL after the fifth.

2) Linux - same hardware for say $2500, CentOS (free). Offer a fixed
twelve hour setup, for a $4000 total. Another $799USD ($AD 1000) to go
with genuine Redhat instead.

> > SQL Server comes with its own backup facility, Exchange adds an
agent
> to
> > NTbackup.
> 
> OK. Then why do most businesses need to buy $5k Exchange and SQL
Server
> backup software, if NTbackup works?

Not for the first time, you're talking about something you're not
familiar with, Con, and it's the result of substituting real "at the
coalface" research, with Google.

They don't need to buy those software products... all of my sites have
used only NTbackup for years ... the Dept of Ed's school admin servers
running IIS, SQL and file and print servers use it too ...

But "free" never equals "best".  

People are happy to pay money for the feature set they like - it's
called "Value Adding". Sysadmins can love the extra things Retrospect
and Backupexec can do. More power to them, I say ... it's their network
...

Cheers,
Clarky


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