Hi Mustak,
I have received some additional information regarding this problem.
Hopefully this email will clear up any confusion that resulted from previous
ermapper-l postings.
Windows NT/2000 allows processes to realize a 32-bit linear address space
for 4GB of memory. However, only the lower 2GB of this private address space
can be utilized by the process as the system reserves the upper 2 GB of
every process's address space for its own use.
As the rectification input and output must be loaded into one contiguous
chunk of virtual memory, their combined size cannot exceed this 2GB process
limit.
This has always been a problem with ER Mapper and is not new to ER Mapper
6.2. We are working on fixing this for the next release.
Hope this helps,
David Carter
QA Officer - ER Mapper
Earth Resource Mapping
Introducing Raster and Vector Integration
Image Web Server 1.6 Released
www.EarthEtc.com
> -----Original Message-----
> From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]] On Behalf Of Mustak Shaikh
> Sent: Monday, 13 August 2001 12:23 PM
> To: [EMAIL PROTECTED]
> Subject: Re: RE: Low Virtual Memory
>
>
> Hi David
>
> The geocoding map to map transformation error occurs on the images of
1.1GB. It works perfectly fine on images around 800MB.
>
> It appears to me ERM either is not recognising the swap space or not
demanding memory. I noticed in the performance window of the task manager
that when you hit ok tab of geocoding wizard, there is no demand or increase
in memory usage. In fact it hardly uses 10-20% of available memory.
>
> I tried increasing swap space to 4GB (min & max) to various combinations
from 500MB minimum to 4GB maximum but without success.
>
> Hope to see solution/patch soon from you.
>
> Regards
>
> ==============================================================
> Mustak Shaikh
> Remote Sensing Analyst Ph: +61-2-9895 7446
> Dept of Land & Water Conservation Fx: +61-2-9895 7742
> 10 Valentine Avenue Email:
[EMAIL PROTECTED]
> Parramatta NSW 2150. Australia http://www.dlwc.nsw.gov.au
> ==============================================================
>
> Disclaimer
> This message is intended for the addressee named and may contain
confidential/privileged information.
> If you are not the intended recipient, please delete it and notify the
sender. Views expressed in this
> message are those of the individual sender, and are not necessarily the
views of the NSW Department of
> Land and Water Conservation. You should scan any attached files for
viruses.
>
> >>> [EMAIL PROTECTED] 08/09 6:25 pm >>>
> Mustak,
>
> In addition to what David Carter wrote, you might find the
> following useful. It's written for Windows 2000, but applies
> equally for Windows NT4.
>
> --------- ---------
> The Windows 2000 (32-bit) operating system imposes a 4Gb restriction on
the
> amount of virtual memory that can be used by each process. (For reference
> see
>
http://www.smartcomputing.com/editorial/article.asp?article=Articles%2FArchi
> ve%2FG0801%2F33x01%2F63g01%2Easp .)
>
> During rectification, ER Mapper needs to hold the input and output files
in
> virtual memory. (You can see the output size on the last page of the
> Geocoding wizard). Typically the output size is similar to the input file
> size, or slightly larger. So for a typical rectification, the dataset must
> be smaller than ~2Gb.
>
> Further. . .
> The virtual memory space required during rectification has to be
contiguous
> (unbroken/continuous). Virtual memory is also used by other applications
and
> the operating system itself, and any other parts of ER Mapper that are
> running. So even if you have lots of free virtual memory, you might not
have
> a sufficiently large contiguous chunk. It may help to restart the PC just
> before rectification, to clear sections used by other applications.
Further
> complications arise if the virtual memory is divided into pieces on
> different hard disks. This contiguity-requirement may effectively reduce
the
> allowable input size even further, below 2Gb.
>
> Below are the possible work arounds (all of which involve making the files
> smaller):
>
> 1. Reduce the number of bands in the output file. (Then re-attach
> later via a VDS.) This is often the best work-around, if you have a
> multi-band dataset.
>
> 2. Increase the output cell size.
>
> 3. Reduce the datatype size (eg unsigned16bit instead of IEEE4).
>
> 4. Cut the INPUT file into tiles.
>
> 5. Use "Output Extents" functionality to limit the area to output to.
> (Then combine the results from multiple warps using the raster merge
> function.)
> This is done from the last page of the Geocoding wizard.>
> --------- ---------
>
> Cheers,
>
> Andrew.
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of david.carter
> Sent: Thursday, 9 August 2001 10:31 AM
> To: [EMAIL PROTECTED]
> Subject: RE: Low Virtual Memory
>
>
> Hi Mustak,
>
> The same problem has been recently reported by two other clients and is
> logged in our bug tracking database(bugref 3618). I have done some tests
> here, and found the problem exists in both ER Mapper 6.1 and 6.2 when
> rectifying large datasets. The dataset I attempted to rectify was 2.4 GB.
> I am currently trying to pinpoint how large a dataset must be before this
> error occurs.
>
> I will keep you updated with further findings,
>
> David Carter
> QA Officer - ER Mapper
> Earth Resource Mapping
>
> Introducing Raster and Vector Integration
> Image Web Server 1.6 Released
> www.EarthEtc.com
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of Mustak Shaikh
> Sent: Thursday, 9 August 2001 8:10 AM
> To: [EMAIL PROTECTED]
> Subject: Re:Low Virtual Memory
>
>
> Hi
>
> We are getting following error message while running geocoding wizard's
map
> to map reprojection.
>
> "Could not map file sydney.ers. System is running low on virtual memory.
> Increase your swap space size. Last system error = 2. No such file or
> directory".
>
> The original image is 1.1GB in size and we are trying to reproject it to
> another projection/datum. We have increased our virtual memory from 523MB
> (recommended) maximum to 3GB but still getting same error.
>
> We are running ERM6.2 with WinNT (Version4.0 Patch5.0) on Pentium-III 866
> twin processors with 512 RAM and two hard disks (8GB and 320GB).
>
> Thanks for your help.
> mustak
>
>
> ==============================================================
> Mustak Shaikh
> Remote Sensing Analyst Ph: +61-2-9895 7446
> Dept of Land & Water Conservation Fx: +61-2-9895 7742
> 10 Valentine Avenue Email:
> [EMAIL PROTECTED]
> Parramatta NSW 2150. Australia http://www.dlwc.nsw.gov.au
> ==============================================================
>
> Disclaimer
> This message is intended for the addressee named and may contain
> confidential/privileged information.
> If you are not the intended recipient, please delete it and notify the
> sender. Views expressed in this
> message are those of the individual sender, and are not necessarily the
> views of the NSW Department of
> Land and Water Conservation. You should scan any attached files for
> viruses.
>
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