Very Computer

I bought myself a new disk, a 9.1Gb AtlasII. The problem is that its reporting
itself as a 8.5Gb disk:-(
Both the documentation and "boot -v" says that the disk has 17.781.520
512bytes sectors, and that gives me and my calculator 8.5Gb. Could _please_
someone tell me im a idiot and explain whats happening here!

Im attaching relevant portions from dmesg and disklabel output.

FreeBSD-Current as of 98-02-26
Adaptec 2940UW, 2 disks + tape on narrow channel and the Atlas on the wide
channel.
Atlas running only at 10MHz beqause i guess that terminating the narrow
channel at the seagate disk is not a good idea. The Atlas disk also
terminating (wide channel). Me buying active terminator :|

/Johan

ahc0: <Adaptec 2940 Ultra SCSI host adapter> rev 0x00 int a irq 10 on
pci0.15.0
ahc0: Reading SEEPROM...done.
internal50 cable is present
internal68 cable is present
brdctl == 0x2c
external cable not present
eprom is present
brdctl == 0xec
low byte termination disabled, high byte termination enabled
ahc0: aic7880 Wide Channel, SCSI Id=7, 16/255 SCBs
ahc0: Resetting Channel A
ahc0: Downloading Sequencer Program...ahc0: 416 instructions downloaded
Done
ahc0: Probing channel A
Choosing drivers for scbus configured at 0
scbus0 at ahc0 bus 0
ahc0: target 0 synchronous at 10.0MHz, offset = 0xf
ahc0: target 0 Tagged Queuing Device
sd is configured at 0
sd0 at scbus0 target 0 lun 0
sd0: <SEAGATE ST11900N 8650> type 0 fixed SCSI 2
sd0: Direct-Access 1621MB (3320691 512 byte sectors)
sd0: with 2621 cyls, 15 heads, and an average 84 sectors/track
ahc0: target 1 synchronous at 10.0MHz, offset = 0xf
ahc0: target 1 Tagged Queuing Device
sd is configured at 1
sd1 at scbus0 target 1 lun 0
sd1: <HP C3725S 5153> type 0 fixed SCSI 2
sd1: Direct-Access 2047MB (4194058 512 byte sectors)
sd1: with 3703 cyls, 9 heads, and an average 125 sectors/track
ahc0:A:6: refuses WIDE negotiation.  Using 8bit transfers
ahc0: target 6 synchronous at 5.0MHz, offset = 0xf
st is configured at 0
st0 at scbus0 target 6 lun 0
st0: <WangDAT Model 3400DX 1.4a> type 1 removable SCSI 2
st0: Sequential-Access density code 0x13,  drive empty
ahc0: target 8 using 16Bit transfers
ahc0: target 8 synchronous at 10.0MHz, offset = 0x8
ahc0: target 8 Tagged Queuing Device
sd is configured at 2
sd2 at scbus0 target 8 lun 0
sd2: <QUANTUM XP39100W LXY4> type 0 fixed SCSI 2
sd2: Direct-Access 8682MB (17781520 512 byte sectors)
sd2: with 5899 cyls, 20 heads, and an average 150 sectors/track

# /dev/rsd2c:
type: SCSI
disk: sd2s1
label:
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 255
sectors/cylinder: 16065
cylinders: 1106
sectors/unit: 17781520
rpm: 7200
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0           # milliseconds
track-to-track seek: 0  # milliseconds
drivedata: 0

8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
  c: 17781520        0    unused        0     0         # (Cyl.    0 - 1106*)
  e: 17781520        0    4.2BSD        0     0     0   # (Cyl.    0 - 1106*)

[Johan Granlund]

|   I bought myself a new disk, a 9.1Gb AtlasII. The problem is that its
|   reporting itself as a 8.5Gb disk:-(
|   Both the documentation and "boot -v" says that the disk has 17.781.520
|   512bytes sectors, and that gives me and my calculator 8.5Gb. Could
|   _please_ someone tell me im a idiot and explain whats happening here!

You're seeing different definitions of "megabyte". All disk manufacturers
I've looked at the last few years use mega = 1000000, while FreeBSD uses
mega = 1048576.

/Johan

Quote:> I bought myself a new disk, a 9.1Gb AtlasII. The problem is that its reporting
> itself as a 8.5Gb disk:-(
> Both the documentation and "boot -v" says that the disk has 17.781.520
> 512bytes sectors, and that gives me and my calculator 8.5Gb. Could _please_
> someone tell me im a idiot and explain whats happening here!

17781520 x 512 = 9104138240 = 9.104 million.

============================================================

Ottawa, ON             FreeBSD: Where you want to go. Today.

Quote:

> Sadly, Marketing and Engineering use different definitions of "Gigabyte".

> 17781520 x 512 = 9104138240 = 9.104 billion.

============================================================

Ottawa, ON             FreeBSD: Where you want to go. Today.

--

  See another pointless homepage at <URL:http://home.pages.de/~naddy/>.

FreeBSD on the other hand says 1Gb == 1024 x 1024 x 1024 which puts your
disk size at 8.48GB

Tony

--Tim Smith