This is the fuzzy part of the course. I don't have
alot of examples so I'll leave some of this to imagination,
but I want to talk about how you get disks ready to be used
by Veritas. First of all, you'll need to have the disks
you want to use attached to the system. When using disks
in Veritas they DO NOT have to be on the same controller,
or anything like that, any disk attached to the system
will work. Once the disks are attached you'll need to make
the OS aware of them, which on Solaris would be:
# drvconfig;devlinks;disks |
After this, the "format" command should display your new disks
in its output. If it is, the disk is now usable by the OS,
and by extension, Veritas.
A quick note on partitioning. DO NOT PARTITION DISKS
FOR USE WITH VERITAS!!! Why do I scream about it? Veritas
does all that for you. Veritas wants a very simple
partition layout, which is default on most disks. If the
partition layout is wrong, Veritas will tell you when you
try to bring it under Veritas control. If you need to
repartition disks for Veritas you can do it with the format
command, and simply restore one of the "default" layouts.
Now we need to bring the disk under the control of
Veritas. Once Veritas gets a disk NO PART of that disk
is usable outside of Veritas. This is why you can't partition
disks before using Veritas, it doesn't want you trying to mess
with ITS disks! (Veritas and the disk form a bit pact of something)
There are two ways to bring a disk under Veritas control,
"encapsulation" and "initialization". They ARE different. Both
methods get your disk ready for use in Veritas volumes. The difference
is that "encapsulation" will preserver your data on the disks. Veritas
just kind of gels around the data and assimilates the disk. Whereas
with "initialization" the data is wiped free and brought into
Veritas control. When initializing all data on the disk being initialized
will me lost. Some times Veritas and it's manuals tend to blur the
difference between the two, so be careful.
To add a disk to Veritas control you can use "vxdiskadm".
This is a ascii-menu driven tool, which allows for some help
assisted, interactive operations. VxDiskAdm is invoked with the
command "/usr/sbin/vxdiskadm". It's output looks like this:
Volume Manager Support Operations
Menu: VolumeManager/Disk
1 Add or initialize one or more disks
2 Encapsulate one or more disks
3 Remove a disk
4 Remove a disk for replacement
5 Replace a failed or removed disk
6 Mirror volumes on a disk
7 Move volumes from a disk
8 Enable access to (import) a disk group
9 Remove access to (deport) a disk group
10 Enable (online) a disk device
11 Disable (offline) a disk device
12 Mark a disk as a spare for a disk group
13 Turn off the spare flag on a disk
list List disk information
? Display help about menu
?? Display help about the menuing system
q Exit from menus
Select an operation to perform: |
To add a disk you'll need to choose with is more
appropriate, option "1" (initialize), or "2" (encapsulate).
For the disks I'm going to use, I'll just initialize.
Before initializing my new disks, it's a good idea
to using the "list" operation in vxdiskadm, just to make sure
that Veritas sees the disks too. Just type "list", and here
is my output:
----------------------------------------------------------------
List disk information
Menu: VolumeManager/Disk/ListDisk
Use this menu operation to display a list of disks. You can
also choose to list detailed information about the disk at
a specific disk device address.
Enter disk device or "all" [<address>,all,q,?] (default: all) all
DEVICE DISK GROUP STATUS
c0t0d0 - - error
c0t1d0 - - error
c2t0d0 disk01 rootdg online
c2t1d0 disk02 rootdg online
c2t2d0 disk03 rootdg online
c2t6d0 - - online
Device to list in detail [<address>,none,q,?] (default: none) |
Notice in the output that disks at t0, t1, and t2 have
already been initialized, so they have a disk name. However,
I haven't initialize c2t6d0. (Again, notice that Veritas
isn't interested in partitions. Where's not specifying sX
in the device name). The following is the full output
of an initialization process of a new disk into Veritas
using "vxdiskadm", option 1. This is kinda long, but notice
how easy and helpful it is!
Add or initialize disks
Menu: VolumeManager/Disk/AddDisks
Use this operation to add one or more disks to a disk group. You can
add the selected disks to an existing disk group or to a new disk group
that will be created as a part of the operation. The selected disks may
also be added to a disk group as spares. The selected disks may also
be initialized without adding them to a disk group leaving the disks
available for use as replacement disks.
More than one disk or pattern may be entered at the prompt. Here are
some disk selection examples:
all: all disks
c3 c4t2: all disks on both controller 3 and controller 4, target 2
c3t4d2: a single disk
Select disk devices to add:
[<pattern-list>,all,list,q,?] list
DEVICE DISK GROUP STATUS
c0t0d0 - - error
c0t1d0 - - error
c2t0d0 disk01 rootdg online
c2t1d0 disk02 rootdg online
c2t2d0 disk03 rootdg online
c2t6d0 disk04 rootdg online
Select disk devices to add:
Add or initialize disks
Menu: VolumeManager/Disk/AddDisks
Use this operation to add one or more disks to a disk group. You can
add the selected disks to an existing disk group or to a new disk group
that will be created as a part of the operation. The selected disks may
also be added to a disk group as spares. The selected disks may also
be initialized without adding them to a disk group leaving the disks
available for use as replacement disks.
More than one disk or pattern may be entered at the prompt. Here are
some disk selection examples:
all: all disks
Add or initialize disks
Menu: VolumeManager/Disk/AddDisks
Use this operation to add one or more disks to a disk group. You can
add the selected disks to an existing disk group or to a new disk group
that will be created as a part of the operation. The selected disks may
also be added to a disk group as spares. The selected disks may also
be initialized without adding them to a disk group leaving the disks
available for use as replacement disks.
More than one disk or pattern may be entered at the prompt. Here are
some disk selection examples:
all: all disks
c3 c4t2: all disks on both controller 3 and controller 4, target 2
c3t4d2: a single disk
Select disk devices to add:
[<pattern-list>,all,list,q,?] list
DEVICE DISK GROUP STATUS
c0t0d0 - - error
c0t1d0 - - error
c2t0d0 disk01 rootdg online
c2t1d0 disk02 rootdg online
c2t2d0 disk03 rootdg online
c2t6d0 - - online
Select disk devices to add:
[<pattern-list>,all,list,q,?] c2t6d0
Here is the disk selected. Output format: [Device_Name]
c2t6d0
Continue operation? [y,n,q,?] (default: y)
You can choose to add this disk to an existing disk group, a
new disk group, or leave the disk available for use by future
add or replacement operations. To create a new disk group,
select a disk group name that does not yet exist. To leave
the disk available for future use, specify a disk group name
of "none".
Which disk group [<group>,none,list,q,?] (default: rootdg)
Use a default disk name for the disk? [y,n,q,?] (default: y)
Add disk as a spare disk for rootdg? [y,n,q,?] (default: n)
The selected disks will be added to the disk group rootdg with
default disk names.
c2t6d0
Continue with operation? [y,n,q,?] (default: y)
The following disk device appears to have been initialized already.
The disk is currently available as a replacement disk.
Output format: [Device_Name]
c2t6d0
Use this device? [y,n,q,?] (default: y)
The following disk you selected for use appears to already have
been initialized for the Volume Manager. If you are certain the
disk has already been initialized for the Volume Manager, then you
do not need to reinitialize the disk device.
Output format: [Device_Name]
c2t6d0
Reinitialize this device? [y,n,q,?] (default: y)
Initializing device c2t6d0.
Adding disk device c2t6d0 to disk group rootdg with disk
name disk04.
Add or initialize other disks? [y,n,q,?] (default: n) |
Easy right? Totally! Now that our disk is added to Veritas
control, we can start using the disk. Since I'm using 4 disks, after
all of them were added to Veritas control "vxprint" output looks like this:
# vxprint
Disk group: rootdg
TY NAME ASSOC KSTATE LENGTH PLOFFS STATE TUTIL0 PUTIL0
dg rootdg rootdg - - - - - -
dm disk01 c2t0d0s2 - 17678493 - - - -
dm disk02 c2t1d0s2 - 17678493 - - - -
dm disk03 c2t2d0s2 - 17678493 - - - -
dm disk04 c2t6d0s2 - 17678493 - - - -
# |
Understand the output? Vxprint is our window into the world of
Veritas. You'll use it extensively. Every time we do something we'll
want to check it with vxprint. Right now, notice that we have 4 disks,
named "disk01", "disk02", "disk03", and "disk04". They are labeled with
"dm", which represents a VM disk. The VM Disks are a member of the "rootdg"
which is the default disk group. The length displayed in the fifth
column is the VM disk length (aka size) in SECTORS! [Sectors can be
converted to kilobytes by dividing by 2. On this system anyway.]
We've now created the foundation for our volumes to come.
We've built VM disks, which are members of a diskgroup (the default
in this case... nothing happens without a disk group). We can
now build "subdisks" which will form our plex!