AIX mksysb medium write error

UNIX AIX
1

I am trying to do a mksysb to a mounted directory that i hava on an ubuntu server. I have 80Gb of space on the ubuntu server. the job fails with message backup medium write error: File to large. What can i do to get this to work?

thanks

2

Hmm,
There are couple of things I can think of

  1. Make sure you have the appropriate permissions to write the mksysb to NFS mount.
  2. Make sure ulimit values are set to unlimited.
  3. If the size of your mksysb is big, try to omit the unwanted stuff by adding /etc/exclude.rootvg file in mksysb.

I hope this helps.

3

i can write files and directories to the mount from AIX. the ulimit on the ubuntu server is set to unlimited. the ulimit on the AIX box is not set to unlimited will that have an affect? If the rootvg is 200Gb and there are 100Gb free. Do in need 200Gb or 100Gb of space for mksysb to write to?

4

You need as much space as is really taken. backup (mksysb is ultimately based on backup ) will need some space for metadata and mksysb information will also take some space but in the end the size of the mksysb image will be about as big as the used space in your VG ("used space" meaning "space taken by files", not "space given to LVs").

There are several limits in place here which could affect operation: first, there is a ulimit for the root user of your AIX machine. It will curtail the size of the mksysb image file root can write.

Second, there might be a FS size limit on the Ubuntu server. See the disk quotas, FS properties and similar things on the Ubuntu server exporting the mount.

Third, when you mount a directory via NFS you need a user local to the exporting server which is used for privilege mangement there: the user in the AIX machine might be root, but when it writes something to the NFS mount this write operation takes place at the remote machine and has to be run under a certain user there - which is NOT the AIX root but some user to which "the root from the remote machine" is translated to. It might even be nobody. (This is why you might see a file in a NFS share where you seem to be the owner but still have no rights on - the user X locally is not (necessarily) the user X remotely.) Check this remote user if there are ulimits in place.

I hope this helps.

bakunin

5

thanks for all the help . once i changed the ulimit to unlimited on the AIX box it worked like a charm.