IRIX and Software

The MOD/M.O.D. (Magneto Optical Drive) IRIX FAQ

The MOD/M.O.D. (Magneto Optical Drive) IRIX FAQ
By Diego A. De Giorgio
Rosario / Santa Fe / Republica Argentina
Monday, May 29, 2006


Overview

I'll intend to write a short FAQ about the use of Magneto Optical Drives on IRIX/4Dwm. I'll cover initially only the Fujitsu MCC3064SS drives, but testings with Olympus MOS320E and others will follow soon.

The above Fujitsu model seems to be among the best of bests about reliability, speed, easiness to configure, and more specially, versatility and price/performance relationship.

I'll add more details on next posts, since this is a work in progress, motivated by an ask from one of my customers. Also, I'll try to include details about the undocumented DIP Switch settings for a few special features that I'm actually testing.

The Shortest Path

Assuming that you already have properly conected and configured your MOD drive to a given SGI system, with a SCSI Controller# (1), SCSI Device ID# (4), and SCSI LUN# (0), just open any command console and do the following:

(1) - Partitioning:

Code: Select all

'fx'
'dksc'
'1'
'4'
'0'
'r'
'o'
'efs' (...or...) 'xfs'
'yes'
'..'
'exit'


(2) - Formatting:

Code: Select all

'mkfs_efs /dev/rdsk/dks1d4s7'   (EFS Filesystem)

(...or...)

'mkfs_udf /dev/rdsk/dks1d4s7'   (UDF Filesystem)

(...or...)

'mkfs_xfs /dev/rdsk/dks1d4s7'   (XFS Filesystem)


(3) - Adding To The Filesystem Mounting Table:

Code: Select all

'nedit /etc/fstab'

(Add One Of The Following Lines)

'/dev/dsk/dks1d4s7 /MOD efs rw 0 0'

(...or...)

'/dev/dsk/dks1d4s7 /MOD udf rw 0 0'

(...or...)

'/dev/dsk/dks1d4s7 /MOD xfs rw 0 0'


(4) - Creating The Mounting Dir:

Code: Select all

'mkdir /MOD'


(5) - Mounting The Unit:

Code: Select all

'/sbin/mount /dev/dsk/dks1d4s7 /MOD'


(5) - Unmounting The Unit:

Code: Select all

'/sbin/umount /dev/dsk/dks1d4s7 /MOD'


(7) - Checking/Fixing The Filesystem:

Code: Select all

'fsck /dev/rdsk/dks1d4s7'


...And, Voila'! ;)



Para Mis Compatriotas, Tambien En Castellano! ;)

El FAQ De Los MOD/M.O.D. (Magneto Optical Drive) En IRIX
Por Diego A. De Giorgio
Rosario / Santa Fe / Republica Argentina
Lunes, Mayo 30, 2006


Generalidades

Voy a intentar escribir un FAQ resumido sobre el uso de Magneto Optical Drives en IRIX/4Dwm. Inicialmente voy a cubrir solamente los drives Fujitsu MCC3064SS, pero pronto seguiran el Olympus MOS320E y algunos otros.

Los modelos Fujitsu parecen ser hasta el momento los mejores en cuanto a confiabilidad, velocidad, facilidad de configuracion, y mas especialmente, versatilidad y relacion precio/performance.

Pronto agregare mas detalles ya que este es un trabajo en progreso. Tambien tratare de incluir mas detalles sobre algunas caracteristicas indocumentadas sobre las configuraciones de los DIP Switchs.

El Camino Mas Corto

Asumiendo que uno ya tiene propiamente conectado y configurado el drive MOD para un determinado sistema SGI, con un SCSI Controller# (1), SCSI Device ID# (4), y SCSI LUN# (0), simplemente abrir una consola de comandos y tipear lo siguiente segun el caso:

(1) - Particionado:

Code: Select all

'fx'
'dksc'
'1'
'4'
'0'
'r'
'o'
'efs' (...o...) 'xfs'
'yes'
'..'
'exit'



(2) - Formateado:

Code: Select all

'mkfs_efs /dev/rdsk/dks1d4s7'   (EFS Filesystem)

(...o...)

'mkfs_udf /dev/rdsk/dks1d4s7'   (UDF Filesystem)

(...o...)

'mkfs_xfs /dev/rdsk/dks1d4s7'   (XFS Filesystem)



(3) - Agregado A La Tabla De Montaje Del Filesystem:

Code: Select all

'nedit /etc/fstab'

(Agregar Una De Las Lineas Siguientes)

'/dev/dsk/dks1d4s7 /MOD efs rw 0 0'

(...o...)

'/dev/dsk/dks1d4s7 /MOD udf rw 0 0'

(...o...)

'/dev/dsk/dks1d4s7 /MOD xfs rw 0 0'



(4) - Creacion Del Directorio De Montaje:

Code: Select all

'mkdir /MOD'



(5) - Montaje De La Unidad:

Code: Select all

'/sbin/mount /dev/dsk/dks1d4s7 /MOD'



(6) - Desmontaje De La Unidad:

Code: Select all

'/sbin/umount /dev/dsk/dks1d4s7 /MOD'



(7) - Revisacion/Reparacion Del Filesystem:

Code: Select all

'fsck /dev/rdsk/dks1d4s7'


...Y, Pan Comido! ;)
The System Used For Testings

Code: Select all

hinv
CPU: QED RM7000 Processor Chip Revision: 5.1
FPU: QED RM7000 Floating Point Coprocessor Revision: 5.0
1 602 MHZ IP32 Processor
Main memory size: 1024 Mbytes
Secondary unified instruction/data cache size: 256 Kbytes on Processor 0
Instruction cache size: 16 Kbytes
Data cache size: 16 Kbytes
FLASH PROM version 4.18
Integral SCSI controller 0: Version ADAPTEC 7880
Disk drive: unit 1 on SCSI controller 0
Disk drive: unit 2 on SCSI controller 0
CDROM: unit 4 on SCSI controller 0
Integral SCSI controller 1: Version ADAPTEC 7880
Disk drive / removable media: unit 4 on SCSI controller 1
PCI SCSI controller 2: Version ADAPTEC 7880
On-board serial ports: tty1
On-board serial ports: tty2
On-board EPP/ECP parallel port
CRM graphics installed
Integral Ethernet: ec0, version 1
Iris Audio Processor: version A3 revision 0
Video: MVP unit 0 version 1.4
AV: AV1 Card version 1, O2Cam type 1 version 0 connected.
Vice: TRE


Code: Select all

scsicontrol -I /dev/scsi/sc1d4l0
/dev/scsi/sc1d4l0:  Disk          FUJITSU M2513A          2000
ANSI vers 1, ISO ver: 0, ECMA ver: 0; supports:  reladdr synch linkedcmds
vendor specific data:
98 00 00 00  00 00 00 00  00 00 00 02  00 19 00 00      ...............
00 00 00 00  00 00 20 41  30 30 37 37
reserved (for SCSI 3) data:
00 00 20 41  30 30 37 37
Device is  ready
About 'mediad' (Not Tested Yet)

(8) - Adding To The 'mediad' Configuration File:

Code: Select all

'nedit /etc/config/mediad.config'

(Add The Following Lines)

'# Check A MOD Device For Insertion And Removal
# Every 60 Seconds
monitor device /dev/scsi/sc1d4l0 inschk 60 rmvchk 60'


(9) - Starting/Stopping The 'mediad' Daemon:

Code: Select all

'/etc/init.d/mediad'

(...or...)

'/etc/init.d/mediad -f' (Foreground Service And Full Debugging)

(...or...)

'/etc/init.d/mediad -l 7 -a' (Background Service And Full Debugging)

(...or...)

'/etc/init.d/mediad -e /dev/scsi/sc1d4l0' (Media Ejecting)
very good description. thanks :D
r-a-c.de
foetz wrote: very good description. thanks :D


You're welcome, Foetz. Maybe it will be useful at some point; you never knows when you could need an M.O.D. on IRIX! ;)
For a while I was kinda hesitant buying one of these, especially considering the cost of the media. Now that blu-ray is *almost* available, I really don't see the point of this, the MO reader is afordable, but the media is so darn expensive. I don't see the application for this.

Storage? Hard drives are Waaay less expensive, even scsi ones.
Archival? Can't beat a tape or few dvds.
mia wrote: Now that blu-ray is *almost* available, I really don't see the point of this, the MO reader is afordable, but the media is so darn expensive. I don't see the application for this.


Legacy.
My customer is a company with dozens of boxes with MOD already installeds, and they need MOD compatibility on a few IRIX boxes that they/ve added to their stuff.

mia wrote: Storage? Hard drives are Waaay less expensive, even scsi ones.
Archival? Can't beat a tape or few dvds.


Tape or DVD does not have a fraction of the reliability that you have on a magneto optical disk. Actually, DVD's and CD's are one of the less reliable supports for critic-mission backups.

[EDIT]

...Also, in addition, the MOD support can be writen, erased, and re-written, re-formatted, or whatever you want, several million times. You could not believe the reliability of this support. My customer operates with this since years, with several platforms, including Indigo(s), Indy(s), O2(s), PeeCee(s), Mac(s), and you would not find a failed media among the big amount of daily used disks. The same disks are used over and over and over, since years. They are a fashion of temporary backup to transport the data easily, and after that, they are re-formatted for the next use. The amount of space available is not relevan at all in this case, since they use only less than 230MB each time. They only care about one thing:

RELIABILITY!, DATA-STABILITY!, PERFORMANCE!

... and there is where the MOD really shines! They are so fast as a good hard disk, and even more reliable and stable than any ATA disk, and also than many SCSI disks too.

Sadly, I could not talk about these company, so you would know that there, the MOD is just THE perfect support... but you'll find many other similiar scenaries on many other real-life events too.
[/EDIT]
indeed. regarding reliability mo disks are hard to beat.
r-a-c.de