HI, my SS20 is running 10.0 and has 2x SuperSPARCII CPUs (since I switched with SS10 with HyperSPARC if you follow my odisseys). It appeared reasonably usable (while with HS 10.0 was unusable), I compiled some stuff, used it... I thought to upgrade from 10.1 and am running the MP kernel. Sysupgrade though crashed this way: sysupgrade: I: Extracting base into / 92% 150 MiB 455.96 KiB/s 00:27 ETA Watchdog Reset Type help for more information <#2> ok [ 9573.4970405] nmi_hard: SMP botch. [ 9573.4970405] cpu0: NMI: system interrupts: 0x400c0000<VME=0,SBUS=0,SC,T,ME> [ 9573.4970405] SX STATUS: 00005400 [ 9573.4970405] SX ERROR : 00000000 [ 9573.4970405] SX DIAG : 00004804 [ 9573.4970405] module0: [ 9573.4970405] mxcc error 0x0 [ 9573.4970405] mxcc status 0xff1410002 [ 9573.4970405] mxcc reset 0x0 [ 9573.4970405] module1: [ 9573.4970405] mxcc error 0x0 [ 9573.4970405] mxcc status 0xff1100000 [ 9573.4970405] mxcc reset 0x4 (WATCHDOG RESET) Not nice! I restarted with single CPU kernel and it completed. So I suppose there is (or was? it is 10.0 kernel of course) stability in MP even with the SuperSPARC processors. sh /usr/sbin/postinstall -s /var/cache/sysupgrade/etc.tgz -s /var/cache/sysupgrade/xetc.tgz -d / fix mtree opeh Note that this may overwrite local changes.