Solaris-Volume-management

###volume management###
Solaris volume managment permits the

creation of 5 object types:
1. volume Raid 0(concatenation or

stripe)/1(mirror)/5(striping with

parity)
2. soft partitions -permits the

creation of very large storage devices
3. Hot spare pools - facilitates

provisioning of spare storage for use

when RAID-1/5 voulume has failed
i.e. Mirror
      -Disk1
      -Disk2
      -Disk3  -spare
4.  state database replica -must be

created prior to volumes
  -contains configuration & status of

all managed objects(volumes/hot spare

pools/soft partitions/etc/)
5. disk sets -used when clustering

solaris in failover mode

Note:Volume Management faciliates the

creation of virtual disks
Note: virtual disks are accessible

via:/dev/md/dsk&/dev/md/rdsk

Rules regarding volumes:
1.state database replicas are required
2.volumes can be created using

dedicated slices
3.volumes can be created on slices

with state database replicas
4.volumes created by voulume manager

(annot be managed using

'format',however, can be managed using

CLI-tools(metadb,metainit) and GUI

tool(SMC)
5. you may use tools such as

'mkfs','newfs','growfs'
6. you may grow volumes using 'growfs'

###state database replicas###
Note: At least 3 replicas are required

for a consistent,functional, muti-user

solaris system.

3 - yields at least 2 replicas in the

event of a failure
Note:if replicas are on same slice or

media and are lost, then voulume

management will fail,causing loss of

data.
Note: Max of 50 replicas per disk set

Note: Volume management relies upon

Majority consensu algorithm(MCA) to

determine the consistency of the

volume information

3 replicas =1.5(half) = 1-rounded-

down+1 =2 = MCA(half+1)

Note: try to create an even amount of

replicas

4 replicas = 2(half)+1=3

stat databasse replicas is

approximately 4MB by default - for

local storage
Rules regarding storage location of

state database replicas:
1. dedicated partition/slice -

c0t1d0s3
2. local partition that is to be used

in a volume(raid 0/1/5)
3. UFS logging devices
4. '/','/usr','swap', and other UFS

partitions cannot be used to store

stat database replicas

###Configure slices to accomodate

state database replicas###

c0t1d0s0 -
c0t2d0s0 -
RAID 0(stripe) -60G - /dev/md/dsk/d0
Note: Volumes can be created using

slices from a single or multiple disks
Note: state database replicas serve

for All volumes managed by bolume

manager

Note: Raid 0 concatenatio - exhausts

disk1 before writing to disk2
Note: Raid 0 stripe -distribute data

evenly across members
Note: use the same size slices when

using RAID0 with striping

Note: after defining volume,create

file system
newfs /dev/md/rdsk/d0

###suggested layout for creating

volumes using volume manager###
Server
   disk0 -system disk
volume manager secondary disks
  -disk1 -secondary disk
  -disk2 -secondary disk

###Raid-1 configuration###
Note: Raid-1 relies upon submirriors

or existing raid-0 volumes
c0t1d0s0 - /dev/md/dsk/d0
c0t2d0s0 - /dev/md/dsk/d1
/dev/md/dsk/d2
 
d0 -source sub-mirror
d1 -destination sub-mirror

create file system on mirrored volume

'/dev/md/dsk/d2'
newfs /dev/md/rdsk/d2

###Raid-5 configuration###
steps:
1. ensure that 3 components

(slices/disks) are available for

configuration
2. ensure that components are

identical in size

slices for raid-5
c0t1d0s0 -10G
c0t1d0s0 -10G
c0t2d0s0 -10G

/dev/md/dsk/d0 =Raid-5=20GB

Note: you may attach components to

raid-5 volume, but they will not store

parity information,however, their data

will be protected.

###using growfs to extend volumes###
growfs extends mounted /unmounted

volumes(UFS/ZFS)
steps to grow a mounted/unmounted file

system
1. find free slices to add as

components to volume using SMC or

mettattach CLI
2. Add component slice -wait for

initialization(concatenation) to

complete
3.execute 'growfs -M /d0

/dev/md/rdsk/d0'

NOte: once you've extended a

volume,you cannot decrease it in size.
Note: concatenation of raid-1/5

volumes yields an untrue raid-1/5

volume.
slice1
slice2
slice3
slice4 -concatenated -Not a true raid

-1/5 member( no parity is stored)

Note: when extending raid-1 volumes,

extend each sub-mirror first, and then

sloaris will automatically extend the

raid-1 volume. then run 'growfs'