Solaris

A mirror Raid system with two disk (probabaly raid1: Sun solaris Netra 240)
the following error occured
when I look at it with metastat :

d101: Submirror of d100
State: Needs maintenance
Invoke: metareplace d100 c1t0d0s5 <new device>

is there any advice that it indicates that disk really is broken ?

have a look at "iostat -eE" and check /var/adm/messages for error reports...

just try to do metareplace on the old disk device again, sometimes could it be due to loose connectivity or the server was physically moved this may happen. If after you do a metareplace a few days later it again says requires maint then it's time to call it in.

one way to check at a glance iostat -en

if you see many hard errors and transport errors (meaning 10 or 20 or more) then forget it collect explorer & call sun straight away.

Hello DukeNuke2, sparcguy. I could not get any error report at /var/adm/messages or iostat output you advised;
here is the output of iostat :
is there any advise on them ?

# iostat -eE
---- errors ---

md0 0 0 0 0
md1 0 0 0 0
md2 0 0 0 0
md3 0 0 0 0
md4 0 0 0 0
md5 0 0 0 0
md6 0 0 0 0
md7 0 0 0 0
md8 0 0 0 0
md9 0 0 0 0
md10 0 0 0 0
md11 0 0 0 0
md20 0 0 0 0
md21 0 0 0 0
md22 0 0 0 0
md23 0 0 0 0
md24 0 0 0 0
md25 0 0 0 0
md26 0 0 0 0
md27 0 0 0 0
md28 0 0 0 0
md29 0 0 0 0
md30 0 0 0 0
md100 0 0 0 0
md101 0 0 0 0
md102 0 0 0 0
sd0 0 0 0 0
sd1 0 0 0 0
sd30 0 2 0 2
nfs1 0 0 0 0
sd0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: FUJITSU Product: MAX3073NCSUN72G Revision: 1503 Serial No: 000631F03D89
Size: 73.40GB <73400057856 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
sd1 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: FUJITSU Product: MAX3073NCSUN72G Revision: 1503 Serial No: 000631F03D8S
Size: 73.40GB <73400057856 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
sd30 Soft Errors: 0 Hard Errors: 2 Transport Errors: 0
Vendor: TSSTcorp Product: CD/DVDW TS-L532U Revision: SI02 Serial No: 08/03/05
Size: 18446744073.71GB <-1 bytes>
Media Error: 0 Device Not Ready: 2 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
#
# iostat -en
---- errors ---
s/w h/w trn tot
0 0 0 0 d0
0 0 0 0 d1
0 0 0 0 d2
0 0 0 0 d3
0 0 0 0 d4
0 0 0 0 d5
0 0 0 0 d6
0 0 0 0 d7
0 0 0 0 d8
0 0 0 0 d9
0 0 0 0 d10
0 0 0 0 d11
0 0 0 0 d20
0 0 0 0 d21
0 0 0 0 d22
0 0 0 0 d23
0 0 0 0 d24
0 0 0 0 d25
0 0 0 0 d26
0 0 0 0 d27
0 0 0 0 d28
0 0 0 0 d29
0 0 0 0 d30
0 0 0 0 d100
0 0 0 0 d101
0 0 0 0 d102
0 0 0 0 c1t0d0
0 0 0 0 c1t1d0
0 2 0 2 c0t0d0
0 0 0 0 sspfs_svr:vold(pid551)
#

do as already suggested... replace the disk with the same disk...

I couldn't see any errors ?
how/where did you see errors ? could you please explain me,
thanks in advance.

i can't see errors, too. but "metastat" seems to have errors... if so, do a "dummy" replace. that means:
replace the disk with errors in "metastat" with itself!