URGENT !!!: SOLARIS 9 -"CANNOT FIND BOOT.BIN" ERROR

It is highly likely your HDD has unrecoverable read errors.  You can run diagnostics to confirm, but since this is such an old system and O/S, then I have got to believe the HDD is well beyond expected life.

Replace the HDD with a PAIR of disks, update to Solaris 11, and use ZFS to mirror the boot drive.

Sorry.

You need to boot in to single user mode (At boot prompt, type b –s).
Run fsck and mount the root filesystem on the HDD with
fsck /dev/rdsk/c0d0s0
mount /dev/dsk/c0d0s0 /mnt

Now check if the file boot.bin exists in /mnt/boot/solaris
If it does not exist, you need copy it from the solaris cd and try to boot again

@rhukat , I  just tried your procedure, but its not working.

I guess I will have to reinstall.

I want to do a backup first, but the server doesn't recognize my external hard drive, so I need to find a solution to format it into ufs

@dlethe, I think you are 100% right.

I want to find a solution to backup my datas from the /var partition, because all the mailbox files from SUN ONE MESSAGING SYSTEMS are stored there, and then I will reinstall the O/S.

My new problem is that the server doesn't let me mount or format my external hard drive so I don't know how to do the backup.

Sorry, you do NOT do the backup.  You need to get that HDD in the hands of a data recovery professional, and be prepared to spend $500+

Every moment that disk is powered up can very well make it worse, also.

No i just want to backup the datas from the messaging system (mails) ? do you know how can I format the external hard drive?? I can't do it from the server..

you can reformat a disk by using the "format" command

yes, I did


#devfsadm -C
#iostat -En (able to see the external hard drive)
#format (unable to see the external hard drive)
 I have tried to fsck and mount the external hard drive without success. Its a brand new western digital external hard drive

is this a SATA/ATA disk inside of a USB enclosure?  If so, then you want to install it internally and hook it up to the native ATA/SATA ports.

 Reason is when you hook up a disk via USB it emulates a SCSI device that causes all sorts of problems.

Its a western digital sata disk similar to the one in the picture below

Solaris 9 may not even have the USB-attached disk target drivers, depending on the patch level.  That could very well be root cause.

See this
http://www.bolthole.com/solaris/usb_sol9.html

and this:
http://www.oracle.com/technetwork/server-storage/solaris/overview/usb-faq-140616.html

If you are afraid that your root fs has been damaged you may mount it readonly (omitting the fsck above) and look for the /var slice as mentioned above.
When there ist still data on your original /var (not mounted under /a/var), you may even try to attach another disk drive (USB, ATA or whatever) and format it, create a filesystem on it, mount it and copy contents from /var onto it.
Depending on the OS and version you used to boot off, you may use USB drives ot not.

Good luck !