Step 2:
The smile :D will tell you that you had better see DiskSuite being in your
plan from the beginning because its a bit of a pain if you need to free
up a slice for the metadbs. Without going to the manual, here are the
next steps …
Suppose that you have the following disks …
Example 1) Sun Sparc 20 with dual drives …
# format
Searching for disks…done
AVAILABLE DISK SELECTIONS:
0. c0t1d0
/iommu@f,e0000000/sbus@f,e0001000/espdma@f,400000/esp@f,800000/sd@1,0
1. c0t3d0
/iommu@f,e0000000/sbus@f,e0001000/espdma@f,400000/esp@f,800000/sd@3,0
Specify disk (enter its number):
Then it seems reasonable to mirror these identical drives. But you
don’t need to have identical drives! You can mirror a 256Mb slice with
a 1Gb slice if you want, I don’t recommend it. DiskSuite will only
mirror 256Mb of the filesystem and ignore the wasted area of the misfit
second submirror slice. For the sake of seeing a real hack, here is my
x86 workstation made from whatever drives were kicking about at the time.
# format
Searching for disks…done
AVAILABLE DISK SELECTIONS:
0. c0t0d0
/pci@0,0/pci1000,1@1/cmdk@0,0
1. c0t2d0
/pci@0,0/pci1000,1@1/cmdk@2,0
2. c0t3d0
/pci@0,0/pci1000,1@1/cmdk@3,0
Specify disk (enter its number):
Take note that these drives are a real miss-mash of whatever. With
DiskSuite, it doesn’t matter that the drive geometry is different (
actually, for performance, it does, but lets not split hairs for now )
you can mirror any thing with almost anything. You can concatenate
anything with anything. Just don’t make your submirrors or
sub-components of a concat on the same drive! That will cause incredible
drive thrashing for obvious reasons.
OK, so here is the partition layout of the Sparc20 :
Target 1 drive …
format> curr
Current Disk = c0t1d0
/iommu@f,e0000000/sbus@f,e0001000/espdma@f,400000/esp@f,800000/sd@1,0
Current partition table (original):
Total disk cylinders available: 3880 + 2 (reserved cylinders)
Part Tag Flag Cylinders Size Blocks
0 root wm 0 – 121 128.67MB (122/0/0) 263520
1 var wm 122 – 364 256.29MB (243/0/0) 524880
2 backup wu 0 – 3879 4.00GB (3880/0/0) 8380800
3 swap wu 365 – 607 256.29MB (243/0/0) 524880
4 unassigned wm 608 – 617 10.55MB (10/0/0) 21600
5 unassigned wm 618 – 2559 2.00GB (1942/0/0) 4194720
6 usr wm 2560 – 3818 1.30GB (1259/0/0) 2719440
7 unassigned wm 3819 – 3879 64.34MB (61/0/0) 131760
Target 3 drive …
format> curr
Current Disk = c0t3d0
/iommu@f,e0000000/sbus@f,e0001000/espdma@f,400000/esp@f,800000/sd@3,0
Current partition table (original):
Total disk cylinders available: 3880 + 2 (reserved cylinders)
Part Tag Flag Cylinders Size Blocks
0 root wm 0 – 121 128.67MB (122/0/0) 263520
1 var wm 122 – 364 256.29MB (243/0/0) 524880
2 backup wm 0 – 3879 4.00GB (3880/0/0) 8380800
3 swap wu 365 – 607 256.29MB (243/0/0) 524880
4 unassigned wm 608 – 617 10.55MB (10/0/0) 21600
5 unassigned wm 618 – 2559 2.00GB (1942/0/0) 4194720
6 usr wm 2560 – 3818 1.30GB (1259/0/0) 2719440
7 unassigned wm 3819 – 3879 64.34MB (61/0/0) 131760
PAY PARTICULAR ATTENTION TO SLICE s4 on these identical drives …
That tiny little slice is where the metadb replica databases are going.
My x86 system is similar but for the moment lets stick with a sane
system that will have identical drives like yours.