Summary : Fail to boot from external cdrom drive

JOSEPH AAJ Chackompally (
Tue, 03 Feb 1998 03:07:59 +0800

Thanks to

Chang Keng Seng <chang@sngns1.CV.Com>
Dan Pritts <>
Syed Zaeem Hosain <>
Noli Aurea <>


Dear Sun-Managers,

I have a Sun Netra I with an internal scsi disk (scsi id 0) and an internal
cdrom (scsi-id 6).

I tried connecting an external cdrom drive (NEC Multispin 6x ) with scsi id
5 and inserted a solaris 2.4 cdrom. At the ok prompt

boot /iommu/sbus/........ ....... .... sd5,0:d

(to boot from the cdrom at scsi id 5)

Is there any other easy command to boot from this cdrom with scsi id 5 ?
What does this last d in this sd5,0:d stand for ?

After I tried booting I got the following error

data transfer overrun : current esp state
esp: State = DATA Last State = DATA_DONE
esp: Latched State = 0x91 < IPND, XZERO,IO > intr = 0x10 <BUS> fifo
Last Msg out : IDENTIFY; last msg in : COMMAND COMPLETE
cmd dump fro Target 5 Lun 0:
cdblen=6 cbd = [0x8 0x0 0x0 0x0 0x1 0x0 ]
pkt_state = oxf < XFER, CMG , SEL, ARB >
pkt_flags = 0x3 pkt_statistics=0x0
cmd_flag = 0x1422 cmd_timeout=60

These messages kept appearing on the console continuously.

I also tried terminating at SCSI ID 5, but the same results.

Thanks and Regards


When Sun first decided to add CD-ROM support, there were already a
number of systems in the field, all of which contained boot proms that
expected to boot from disks with 512 byte sectors. Sun had to decide
between replacing a whole lot of boot proms or finding a way to make a
CDROM act like a disk with 512 byte sectors in order to support it as a
boot device. They chose the latter approach.

Many third party CD-ROM drives use 1024 or 2048-byte sectors, which
the SCSI driver to see a "data overrun". When the driver asks for N
"blocks" (which it thinks are 512 bytes each ) it gets more data back
it expected.

Please see

to know how to Modify Solaris 2.4 to 2.5.1 for PC type CD-ROM drives

I did as what was told here and it worked.

Thanks and Regards