file size limit on IFS ?

file size limit on IFS ?

Post by Jim F Cook » Wed, 03 Oct 2007 02:59:09

I am trying to back up a Windows server onto a shared folder on an iSeries
The backup ended when it reached it's time limit, so I know something is
wrong, and it produced an exactly 4 Gb backup file, which is also
suspicious. I was expecting a backup file close to 30 Gb.

Is there a 4 Gb file size limit on the IFS or on the QZLSFILET job? If so,
how can I change this limit?


file size limit on IFS ?

Post by CRPenc » Wed, 03 Oct 2007 06:09:19

A 4GB limit is noted at the following link, but for a "Maximum file
size that can be read or written using the iSeries?Access File Server"
QZLSFILE search of InfoCenter will show that is [for] iSeries
I think the iSeries Access File Server is a function of QPWFSERV
jobs, so that 4GB limit seems unrelated. Other limits for number of
open files and maximum stream file size are listed in the above link; I
did not see any others stating 4GB.

The /same/ 4GB statement in the V5R3 documentation [revised in v5r4],
suggested that the "Maximum file size that can be read or written using
the iSeries Access File Server or the QNTC file system 4GB"; but since
/QNTC is a share in the opposite direction, I do not think it applies:

Were there any errors in the QZLSFILET job servicing that share, or
any messages in the history for that job [since it was activated]?; see
DSPLOG QHST JOB(jobnbr/QUSER/QZLSFILET) /* for an appropriate PERIOD(()) */

Regards, Chuck
All comments provided "as is" with no warranties of any kind
whatsoever and may not represent positions, strategies, nor views of my


file size limit on IFS ?

Post by Jim F Cook » Fri, 05 Oct 2007 00:08:51

Thanks for the info.
No, there are no error messages for the QZLSFILET job. And no errors on the
Windows side
Any other suggestions would be welcome.



file size limit on IFS ?

Post by Jim F Cook » Fri, 05 Oct 2007 00:23:12

I just talked to my Windows engineer.
He said that when the IFS is shared out to Windows systems, it emulates the
FAT32 file system, and there is a 4 Gb limit. So I may end up backing this
server up to another Windows server that has some capacity.



file size limit on IFS ?

Post by Margaret F » Sun, 07 Oct 2007 01:28:23

We (IBM) have seen this with customers using ntbackup and there is an open
service ticket with Microsoft on it. The System i NetServer will support
accessing files larger than 4GB on V5R4, and in fact notifies Windows that
it is NTFS.

file size limit on IFS ?

Post by bdhano » Tue, 09 Oct 2007 22:39:15

ear Margaret Fenlon,

So what do you suggest in this scenario? I am also trying to backup my
servers to AS400 IFS using NTBackup. we are at V5R3 on our AS400. All
my backups over 4GB takes for ever. Up to 4GB the process is quick.

In one of my test cases when I tried to backup 8GB of data. My First
4GB were transferred to IFS in about an hour but completion of 8GB
took 3-4 days.

So the rate of transfer of data decreases dramatically when the file
size on IFS exceeds 4GB.

Please advise.
I will highly appreciate any help.

thanks a lot in advance and regards

On Oct 5, 12:28 pm, "Margaret Fenlon" < XXXX@XXXXX.COM > wrote: