Solution : https://service.sap.com/sap/support/notes/138816 (SAP Service marketplace login required)
Key words : 
symptom archiver stuck hp/ux 10, $oracle_home/dbs/init<sid>, command     svrmgr> archive log, svrmgr> archive log, additional key words, undefinable time interval, log_archive_buffers = 1       log_archive_buffer_size = 512restart, file system level, offline redo logs, sap archiver directory
Related Notes : 
       
| 546006 | Problems with Oracle due to operating system errors | 
| 151712 | After Archiver Stuck the ARCH process does not continue |