Adding Harddisk to VA 7400 storage

[Sandy_hp]

Hi Guys,

I am sandy..and new to hp site..
Guys i have a problem in My HP storage its a HP StorageWorks VA7400 with Diskstation DS2405.
Now I have 15*36 GB HDDs in VA7400 and 9*36 GB HDDs in ds2405.
Two RGs(redundent grps).

I want to increase the storage space by 200 Gb.
can I add 73*3 HDDs to the array.I went throug the manual which says that one RG has all odd no of disks and other Even no .

My Query is that will I get additional space of 200 gb .also what is the process on adding the disks..
any steps to be kept in mind while configuring the hdds in VA7400

guys waiting 4 u replys.

thanks in advance ..

[melvyn burnard]

posted in wrong forum, moved to more appropriate forum

[goldboy]

Sandy welcome to the forums,
73G disks can be added to the array.
as you mentioned, there are 2 redundency groups which means any disk that will be added in the odd slot number will belong to redundency group 1 and even number will belong to redundency group 2.
when creating LUN's to add more space to your system you will have to create the LUN's from group 1 or 2.

If your settings are to auto include a disk drive then as soon as you plug a disk into the array it will automaticly be included and formated, if not then using the command view SDM, in the diagnostic tab you will have the option to include the disk manualy.

Tal

[goldboy]

also, check this thread:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1062712

[Torsten.]

Hi and welcome to the forums,

You won't get 200GB from your 3 disks, because the array will need space for redundancy. This depends on your setting (RAID0/1 or AUTORAID).

Use commandview to review your settings. If autoinclude is enabled, you may insert the disks. It will take up to 45 min to format the disks. Once finished, the array will use the disks and more space is available.

[Sandy_hp]

Thanks Tal and torsten for the warm welcome,

I checked the array settings in the command view SDM and below are what i could understand from it:

1. Redundancy takes up around 3 * size of 1HDD
(for rg1 it is 93.55 and the 1 HDD is 33.375)

2. Active spare is size of 1 HDD (33.375 Gb)

So out of 13 HDD *33.375=433 ,The logical space available is 307 GB.

What I wanted know was :

1. Is the calculation independent of disk size.If I use the 73 GB disk , will it still take 3 times for redundancy and 1 for Active spare(active spare setting as auto)

2.my second rg has

LOGICAL DRIVES 251.273
REDUNDANCY 82.516
ACTIVE SPARE 33.375
TOTAL 367.164

and uses 11 disks..

how can I alter the second RG to get 400 Gb of logical drives.

is there any formule specific for calculating the no of disks required to get 400 gb in rg2..???


3. If the above formule is independent of disks..how much space will redundancy take if I add 6*72 GB hdd to the array .

Will it be 3*72 for each rg?

Active spare will be 72 GB ..


4. Or Do anyone have any other method to increase the free space to 700 gb ..presently it is 558 gb .the details of both rg s are as below.

RG 2
LOGICAL DRIVES 251.273
REDUNDANCY 82.516
ACTIVE SPARE 33.375
TOTAL 367.164
RG 1
LOGICAL DRIVES 306.992
REDUNDANCY 93.554
ACTIVE SPARE 33.375
TOTAL 433.921

[goldboy]

Sandy,
any time you add a disk to a RG the space of the disk will be devided into space for data, space for redundency and hot spare space.
all these are depending on your settings, In the redundency space is depended weather you picked raid 0+1 or raid 5 (50% or 33% appx), the hot spare space allocated from the disk is based on your hot spare settings (auto, 1 disk, 2 disk).

I can send you an intresting HP document that explains all the VA features.
the document is a little big to be added to the forum so if you provide me with an Email address or FTP site i can send it to you.

Tal

[Sandy_hp]

..hey tal..

My raid setting is Autoraid ..i e RAID 1+0
RAID 5.Also hot spare is also set as auto.

please send my the related documents .
my email id is sandeephanson@gmail.com

Also...was I right with those calculation.


Thanx,

Sandy_hp

[goldboy]

Sandy,
Check the documents I sent you they will have all the answers.
htey include explanations about the hot-spare calc'.
I am sure after reading the documents you will have answers to your questions.

If you have any more questions after reading the matriel let me know.

Tal

[Sandy_hp]

Thanks tal ,

I went through the files ...Well It was really helpful..
I could nt find any calculation process. though but did understood the working of the VA .

I am planing to replace the RG2 which has 11 36gb hdds with 10 73 gb hdds.

out of 10 , 3(redundancy)+1(hot spare)=4 hdd will be used by VA7400 and only 6 hdd space will be available as logical drive(6*72=432GB).which will make the total available space to 739 GB.

what do u think..

should i go for it..