"sql error -903 Host file I/O error" during MaxDB Backup

we are using MaxDB 7.5 with R/3 46C on Win 2003 64bit . We try to execute

a full backup of the maxdb .

We schedule the backup via at command using this command:

dbmcli -d ABC -u control,control -uUTL -c backup_start full_backup

THe backup starts but after some hours, after about 40GB have been

saved we receive this error:

"sql error -903,Host file I/O error"

We did more attempts but the backup is always interrupted after about 40 GB of data saved. The abend occurs always after about 3h from the start.

We didn't find any Oss Note for this error.

Regards