thanks a lot for your good and founded answers!
Juraj Salak


> -----Original Message-----
> From: Jim Smith [mailto:smithjp AT US.IBM DOT COM]
> Sent: Thursday, January 09, 2003 2:05 AM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Re: Sub-File Backup - 1 GB Limit
>
>
> Subfilecachesize could be raised; please submit a requirement
> and let us
> know what types of cache sizes you need.  The cache size is
> not bounded by
> the 32-bit differencing image limit.
>
> System objects and subfile processing would be very
> difficult.  I would
> suggest pushing a requirement for incremental processing of
> system files,
> which are the files that get resent on every system object
> backup that are
> probably causing the majority of your woes.   That would probably
> alleviate your problem and be a more applicable solution to
> other problems
> in this area.
>
> Thanks,
> Jim
>
> Thanks,
> Jim
>
> J.P. (Jim) Smith
> TSM Client Development
> smithjp AT us.ibm DOT com
>
>
> Hi Jim
>
> postings from development are always welcome.
>
> Beeing curious I (mis)use your readiness and ask
> you prior to opening a requirement:
>
> Are you limited with 32-bit addressing
> with SubFileCachesize with its maximum of 1 GB as well,
> or would it be simple for you to raise this limit
> significantly higher?
>
> The business case is ability to backup (almost) whole filesystems
> on small file servers over leased lines with limited throughput.
>
> And - any would it be troublesome to apply differencing technology for
> system objects backup?
> The business case is ability to backup enormous system objects from
> servers
> with microsoft systems over leased lines with limited throughput.
>
> best regards
> Juraj Salak, Asamer Holding
>
>
>
>
> > -----Original Message-----
> > From: Jim Smith [mailto:smithjp AT US.IBM DOT COM]
> > Sent: Monday, January 06, 2003 10:00 PM
> > To: ADSM-L AT VM.MARIST DOT EDU
> > Subject: Re: Sub-File Backup - 1 GB Limit
> >
> >
> > Tim,
> >
> > Actually, two different behaviors based on two-different
> > problems.   Files
> > that start less then 2 GB but grow > 2 GB will continue to
> use subfile
> > backup as long as the other requirements for the base file
> > (i.e., the file
> > on the client cache) is still valid.  The limiting factor
> here is that
> > there is only 32-bit support in the differencing subsystem
> that we are
> > using.  We chose 2 GB on the onset (instead of 4 GB) as the
> > limit to avoid
> > any possible boundary problems near the 32-bit addressing
> > limit and also
> > because this technology was aimed at the mobile market (read:
> > who is going
> > to have files on their laptops > 2 GB).  I understand that there are
> > several shops that use this technology beyond the laptop
> environment.
> > Ultimately, the solution is to have a 64-bit subsystem in
> > place so that we
> > can go beyond 4 GB.  I suggest a requirement to Tivoli if this is
> > important to your shop.
> >
> > The low-end limit (1024 bytes) was due to some strange behavior with
> > really small files, e.g., if a file started out at 5 k and then was
> > truncated to 8 bytes.  The solution was to just send the
> > entire file if
> > the file fell below the 1k threshold.  We can get away with
> resending
> > these small files because ... they are small files!  It is
> > probably a wash
> > to resend or to try to correctly send a delta file in this case.
> >
> > Hope this helps.
> >
> > - Jim
> >
> > J.P. (Jim) Smith
> > TSM Client Development
> > smithjp AT us.ibm DOT com
> >
> >
> > Thanks Jim!
> >
> > I was confusing "size of base file falls < 1024" with 1 GB!
> >
> > So if a file starts at less than 2 GB but then grows bigger
> > than 2GB it
> > will
> > no longer be eligible?  Similar if a file falls below 1024 bytes?
> >
> > Thanks again!
> >
> > Tim
> >
> > -----Original Message-----
> > From: Jim Smith [mailto:smithjp AT US.IBM DOT COM]
> > Sent: January 3, 2003 4:36 PM
> > To: ADSM-L AT VM.MARIST DOT EDU
> > Subject: Re: Sub-File Backup - 1 GB Limit
> >
> > Tim,
> >
> > Actually, the subfile limit is 2 Gig; if a file size > 2 Gig
> > then TSM will
> > not bother to copy the base file to the client cache, so it
> > could not be a
> > candidate for subfile processing on a subsequent backup.
> >
> > Thanks,
> > Jim
> >
> > J.P. (Jim) Smith
> > TSM Client Development
> > smithjp AT us.ibm DOT com
> >
> >
> > Last August, Jim Smith wrote:
> >
> >
> > >Today the client code will send a new base file in these cases:
> > >
> > >- if the last time the detla was taken, the ratio of
> > delta:base is > .40
> > >- digital signature of base is incorrect or doesn't match
> > signature on
> > >server
> > >- base entry on client cache is dirty, i.e., never committed on the
> > server
> > >- size of base file falls < 1024
> > >- file is excluded from subfile backup processing, i..e,
> > exclude.subfile
> > >- file is encrypted by Windows efs
> >
> >
> > I just want to double check, does this mean that there is
> > still the 1GB
> > limit for subfile backup?  Ie. If a file is > 1 GB, is it
> > ineligible for
> > subfile processing?
> >
> > Thanks,
> >
> > Tim Rushforth
> > City of Winnipeg
> >
>