Specifications & Manual
https://www-304.ibm.com/systems/support/supportsite.wss/docdisplay?brandind=5000008&lndocid=MIGR-58359

IBM Dynamic System Analysis (DSA) Bootable version download
http://www-304.ibm.com/systems/support/supportsite.wss/docdisplay?lndocid=MIGR-5071800&brandind=5000008

IBM Dynamic System Analysis (DSA) general software matrix
http://www-304.ibm.com/systems/support/supportsite.wss/docdisplay?brandind=5000008&lndocid=SERV-DSA#xseries

Diagnostic error codes - IBM eServer xSeries 345
https://www-304.ibm.com/systems/support/supportsite.wss/docdisplay?lndocid=MIGR-53292&brandind=5000008

Flash BIOS update (DOS update package) - IBM eServer xSeries 345
https://www-304.ibm.com/systems/support/supportsite.wss/docdisplay?lndocid=MIGR-43902&brandind=5000008

Forum
http://www.ibm.com/developerworks/forums/forum.jspa?forumID=740

Hardware compatibility list
http://www-03.ibm.com/servers/eserver/serverproven/compat/us/xseries_old/x345.html

Cable accessories - IBM eServer xSeries 345
https://www-304.ibm.com/systems/support/supportsite.wss/docdisplay?lndocid=MIGR-43578&brandind=5000008

"LSI-1030 integrated RAID controller" capabilitys
EN: http://publib.boulder.ibm.com/infocenter/eserver/v1r2/index.jsp?topic=/diricinfo/fqy0_troscsiq.html
DE: http://publib.boulder.ibm.com/infocenter/eserver/v1r2/index.jsp?topic=/diricinfo/fqy0_clsi10x0.html
The integrated controller can serve/create only one raid1 volume of two discs (+ 1 hot spare)
:-(

IBM Server Simulators
http://www-304.ibm.com/systems/support/reflib/simulators/
Great resource!!!