I'm having these weird errors.

svc.configd: Fatal error: Backend copy failed: fails to read from /etc/svc/repository.db at offset 106496: Bad file number
svc.configd: Fatal error: unable to create "boot" backup of "/etc/svc/repository.db"
Mar 10 13:04:23 svc.startd[7]: svc:/network/iscsi/initiator:default: Method "/lib/svc/method/iscsid" failed with exit status 96.
Mar 10 13:04:23 svc.startd[7]: network/iscsi/initiator:default misconfigured: transitioned to maintenance (see 'svcs -xv' for details)

did you looked at log file (/var/log/)

Is your system up?

who -r
showrev
svcs -xv
df -h

The log files didn't mention anything about these errors... Just sendmails because of my domain. (or lack of one)

$ who -r
   .       run-level 3  Mar 10 13:04     3      0  S
$ showrev
Hostname: solaris
Hostid: 83514575
Release: 5.10
Kernel architecture: sun4u
Application architecture: sparc
Hardware provider: Sun_Microsystems
Domain:
Kernel version: SunOS 5.10 Generic_142900-03
$ svcs -xv
svc:/network/iscsi/initiator:default (?)
 State: maintenance since Wed Mar 10 13:04:23 2010
Reason: Start method exited with $SMF_EXIT_ERR_CONFIG.
   See: http://sun.com/msg/SMF-8000-KS
   See: /var/svc/log/network-iscsi-initiator:default.log
Impact: This service is not running.
$ df -h
Filesystem             size   used  avail capacity  Mounted on
/dev/dsk/c1t0d0s0      2.2G   392M   1.8G    18%    /
/devices                 0K     0K     0K     0%    /devices
ctfs                     0K     0K     0K     0%    /system/contract
proc                     0K     0K     0K     0%    /proc
mnttab                   0K     0K     0K     0%    /etc/mnttab
swap                   5.5G   1.1M   5.5G     1%    /etc/svc/volatile
objfs                    0K     0K     0K     0%    /system/object
sharefs                  0K     0K     0K     0%    /etc/dfs/sharetab
/dev/dsk/c1t0d0s6      4.5G   1.3G   3.1G    31%    /usr
/platform/sun4u-us3/lib/libc_psr/libc_psr_hwcap1.so.1
                       2.2G   392M   1.8G    18%    /platform/sun4u-us3/lib/libc_psr.so.1
/platform/sun4u-us3/lib/sparcv9/libc_psr/libc_psr_hwcap1.so.1
                       2.2G   392M   1.8G    18%    /platform/sun4u-us3/lib/sparcv9/libc_psr.so.1
fd                       0K     0K     0K     0%    /dev/fd
/dev/dsk/c1t0d0s1      1.9G   855M   1.0G    45%    /var
swap                   5.5G     8K   5.5G     1%    /tmp
swap                   5.5G    24K   5.5G     1%    /var/run
/dev/dsk/c1t0d0s5       51G   7.5G    43G    15%    /opt
/dev/dsk/c1t0d0s7      3.9G   842M   3.1G    22%    /export/home
$

system looks OK. Btw, are you using iscsi protocol for any services?

you can check /etc/svc/volatile/db_errors. also check out Sun Message ID: SMF-8000-MY.

Can you reboot again? Does this happen again?