Need break down to c0t0d0s1 and the like

[MargeG]

How do you identify c0t0d0s1.....I know it is a block device name, but...
what is the c
what is the t...etc
what are all the components of this block device name.
It is problably a silly question, but no luck in my research.
I'm transitioning from AIX to Solaris for backups and need as much info as possible.
Thanks

 

[Kegnut]

Someone can go into a little more detail than me, but this is what I think I know, although it's been a while.

c=scsi controller #
t=target #
d=disk #
s=slice #

In my dealings the root disk is typically c0t0d0 but that's not always the case on bigger servers. If you have the 0 partition configured as /, then the device name of the / partition on your root disk would be c0t0d0s0.

I might have confused you more, but hopefully someone can elaborate better. Hope this helps a bit.

J

 

[julianbarnett]

Kegnut is correct

c - is the physical SCSI controller card in your server

t - is the SCSI target ID of the device on the SCSI chain

d - is the device no. - standard SCSI disks normally only have one disk on each target - d0 but RAID arrays, EMC disks etc. use what are called LUNs (Logical Unit Numbers) to have multiple disks on each SCSI target. Sometimes you need to make alterations to the /etc/kernel/sd.conf (SCSI kernel configuration file) to enable this.

s - slice (partition). By default Solaris only allows 8 slices (0-7) on a disk. Slice 2 cannot be used since it is used to refer to the whole disk. If you use the format command and print the partition table you will see htis slice equates to the size of the whole disk with the spurious tag 'backup'. I guess a dd of it would 'backup' the entire disk