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System Details:

O/S: AIX 4.3.3 ML9
RDBMS: Informix IDS 7.31 UC3

We have a routine that is trying to unload an Informix database and
store it to a file system, then back up that file to tape. The database
has reached 2GB in size, and so we have now run into what we believe is
an AIX limitation.

Here are some things we have addressed so far:

1) The file system was not large-file enabled. We recreated it. lsjfs
now shows "Bf=true".

#MountPointevice:Vfs:Nodename:Type:Size:Options: AutoMount:Acct:OtherOptions:LvSize:FsSize:FragSize :Nbpi:Compress:Bf:AgSize:
/cmunload:/dev/cmunloadlv:jfs:::6291456:rw:yes:no::6291456:629145 6:4096:4096:no:true:64:

2) Verified the soft and hard filesize limits on root, informix, and
default. fsize is unlimited and the hard filesize is not set so should
be same as fsize based on the /etc/security/limits file comment lines.

default:
fsize = -1
core = 2097151
cpu = -1
data = 262144
rss = 65536
stack = 65536
nofiles = 3500

root:

informix:

3) We realized that the cpio command we would use will also run into
problems when we write to tape, so our script has been changed to use
the "backup" command.

4) Verified our Informix onunload command is set to limit the size of
the backup to 30GB, and not 2GB.

onunload -t /cmunload/database.unl -b 16 -s 30000000000 cmdb1


RESULTS:
We are not even getting to the point of writing to tape. When the
Informix database is unloading, it gets to 2GB and then dies. The file
is exactly the same size each time we try to extract the data:

-rw-r--r-- 1 informix informix 2147483136 Jul 22 00:59 database.unl

Is there some other area of AIX 4.3 that would limit the size of the
file that is allowed to be created?

Alternatives we are checking into:

A) Upgrade to AIX 5.2 and create a JFS2 to see if this removes the
limit.

B) Extract the database table by table, creating smaller unload files
within the /cmunload file system.

C) Checking the Informix 7.31 for any file size limits it may also
have.

Please advise if anyone has any other ideas.

Steve

steven_nospam at Yahoo! Canada wrote:
> System Details:
>
> O/S: AIX 4.3.3 ML9
> RDBMS: Informix IDS 7.31 UC3
>
> We have a routine that is trying to unload an Informix database and
> store it to a file system, then back up that file to tape. The database
> has reached 2GB in size, and so we have now run into what we believe is
> an AIX limitation.
>
> Here are some things we have addressed so far:
>
> 1) The file system was not large-file enabled. We recreated it. lsjfs
> now shows "Bf=true".
>
> #MountPointevice:Vfs:Nodename:Type:Size:Options: AutoMount:Acct:OtherOptions:LvSize:FsSize:FragSize :Nbpi:Compress:Bf:AgSize:
> /cmunload:/dev/cmunloadlv:jfs:::6291456:rw:yes:no::6291456:629145 6:4096:4096:no:true:64:
>
> 2) Verified the soft and hard filesize limits on root, informix, and
> default. fsize is unlimited and the hard filesize is not set so should
> be same as fsize based on the /etc/security/limits file comment lines.
>
> default:
> fsize = -1
> core = 2097151
> cpu = -1
> data = 262144
> rss = 65536
> stack = 65536
> nofiles = 3500
>
> root:
>
> informix:
>
> 3) We realized that the cpio command we would use will also run into
> problems when we write to tape, so our script has been changed to use
> the "backup" command.
>
> 4) Verified our Informix onunload command is set to limit the size of
> the backup to 30GB, and not 2GB.
>
> onunload -t /cmunload/database.unl -b 16 -s 30000000000 cmdb1
>
>
> RESULTS:
> We are not even getting to the point of writing to tape. When the
> Informix database is unloading, it gets to 2GB and then dies. The file
> is exactly the same size each time we try to extract the data:
>
> -rw-r--r-- 1 informix informix 2147483136 Jul 22 00:59 database.unl
>
> Is there some other area of AIX 4.3 that would limit the size of the
> file that is allowed to be created?
>
> Alternatives we are checking into:
>
> A) Upgrade to AIX 5.2 and create a JFS2 to see if this removes the
> limit.
>
> B) Extract the database table by table, creating smaller unload files
> within the /cmunload file system.
>
> C) Checking the Informix 7.31 for any file size limits it may also
> have.
>
> Please advise if anyone has any other ideas.
An upgrade to AIX 5.2 would get you up on a supported OS release.
Having said that, here is some additional info you might consider.


I think you want to look into a "named pipe". We had a similar problem
with Oracle on 4.3.3,
doing exports.

This command creates the named pipe on AIX. mknod /tmp/exp_pipe p

This starts the export, writing to the named pipe.
exp file=/tmp/exp_pipe


This starts compress reading from the named pipe and
writing to tape.
compress < /tmp/exp_pipe > /dev/rmt0


Here is a link with some additional info on named pipes:

http://www.prstech.com/src/logical_l..._to_disk.shtml



>
> Steve

check out the named pipe items at the following link

http://www.oreilly.com/catalog/unixbr/chapter/ch14.html

Thanks dude! You know the ironic thing is that I found that same
answer...in our own knowledge base entries! Some days the brain cramps
are worse than others...


---- Knowledge Base ----
Unloading/Loading an Informix Database Larger Than 2GB

Due to file size limitations, it is sometimes a problem to try and
extract data from a database if the resulting file would be larger than
2GB in size. However, there are ways around the limitation. Below is
one example of how to accomplish this.

To Unload A Database:
Change directory into a temp filesystem where you will be unloading the
database (make sure the filesystem is created using the large file
system enabled option in AIX).
cd /tempdir

Create the dummy raw device:
mknod dbname p

Change the permission and ownership on the file to the following:
chmod 660 dbname
chown informix:informix dbname

Redirect writing to this file to a compressed file:
cat dbname | compress > dbname.Z &

Become informix and set your environment to unload the database:
su - informix
. set.{instance_name}

Issue the onunload command:
onunload -t /tempdir/dbname -b 16 -s 3000000000 dbname

To Load the Database:
Change directory into a temp filesystem where you will be uncompressing
the database (make sure the filesystem is created using the large file
system enabled option in AIX):
cd /tempdir
uncompress dbname.Z

Once uncompressed, change the permission and ownership on the file to
the following :
chmod 660 dbname
chown informix:informix dbname

Become informix, set your environment and load the database:
su - informix
. set.{instance_name}

Issue the onload command:
onload -t /tempdir/dbname -b 16 -s 30000000000 -d datadbs dbname

no problem, I find this group as good as most vendors support
glad to help