disk issue

[Pluto_2]

Dear expert,

while running dd getting following output.

dd if=/dev/rdsk/c2t0d0 of=/dev/null bs=1024k dd read error: I/O error
7739+0 records in
7739+0 records out

Please suggest is this indicate any disk failure even though records in is equal to records out.
Aman

[Ishwar_1]

Example for :-
Successful read of the first 64 megabytes of the disk:
# dd if=/dev/rdsk/c0t5d0 of=/dev/null bs=1024k count=64
64+0 records in
64+0 records out
Unsuccessful read of the whole disk:
# dd if=/dev/rdsk/c1t3d0 of=/dev/null bs=1024k
dd read error: I/O error
0+0 records in 0+0 records out

Find the below Link for your refrence:-
http://docs.hp.com/en/5991-1236/When_Good_Disks_Go_Bad_WP.pdf

[Pluto_2]

here i m confuse becuse even though read error is there but the records in = records out.

[Ishwar_1]

"read error is there but the records in = records out."

Upon completion of command, dd reports the number of input and output records:

If the Input record is equal to the Output record, its suggest disk is functioning properly, if not its failing then.

You can also use "diskinfo" command to check disk status. If the reported size is nonzero, disk is functioning properly.

[Dennis Handly]

>even though read error is there but the records in = records out.

The records will match whether the disk is good or bad. One failure indication is the fact that it said "read error", another is the fact that the record count doesn't match the size of the disk.

>Ishwar: If the Input record is equal to the Output record, its suggest disk is functioning properly

Why would you say that? All it means is that it read N records, got an error and had no problems writing the records to /dev/null.

[Hakki Aydin Ucar]

Hi,
Additionally you can check this out:

# ioscan -fnCdisk

to see if any not CLAIMED status available,

and you can use;

# echo 2400?20X | adb /dev/dsk/c2t0d0

to see if any badblock is there:
Command output should be as follows (if there are no disk errors).

2400: 44454645 43543031 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0

Those counters indicate of BBDIR that BadBlockDirectory any Bad Sector occurs in any disk , these numbers will be registered into these counters;
So, any non zero numbers indicate bad blocks and that disk should be changed on the spot !