topic Re: Storage MSA500 - RAID 5 in MSA Storage

Storage MSA500 - RAID 5

BiancaP. — Fri, 06 Mar 2015 07:03:31 GMT

Hello!

I have a storage with this caracteristics:
MSA500 G2 with 2 controllers (for redundancy)
10 x 146GB disks (14 slots in total)
MSA500 G2 4-port IO Module
Power: 735V (max)

And I use the Array Configuration Utility to create Logical Drive in my 10 disks.
I always choose the RAID 5 to my Logical Drive.

Do you know how is that?
Lik...what is the disk use to redundancy?
How can i confirme that i have a data redundancy?

P.S. This thread has been moved from General to Storage Area Networks (SAN) (Small and Medium Business). - Hp forum Moderator

Re: Storage MSA500 - RAID 5

TTr — Thu, 07 Aug 2008 18:18:14 GMT

> what is the disk use to redundancy?
You have no control over this. The redundancy in RAID5 is stipe based (parity) and is distributed to all disks using a different disk for each stripe.

> How can i confirme that i have a data redundancy?
Do a test and pull one of the drives. There should be no data lost, only error messages about a missing disk.

You should make one of the 10 disks a "hot spare" so that if a disk fails, the hot spare is used in place of the failed disk.

Re: Storage MSA500 - RAID 5

BiancaP. — Thu, 07 Aug 2008 18:29:38 GMT

Thanks!!

> You should make one of the 10 disks a "hot spare" so that if a disk fails, the hot spare is used in place of the failed disk.

Yes. I check and I don't have this:

Physical Drives Attached to Port 1 Box 1 : Bay 1, 146 GB (Parallel SCSI)
Box 1 : Bay 2, 146 GB (Parallel SCSI)
Box 1 : Bay 3, 146 GB (Parallel SCSI)
Box 1 : Bay 4, 146 GB (Parallel SCSI)
Box 1 : Bay 5, 146 GB (Parallel SCSI)
Box 1 : Bay 6, 146 GB (Parallel SCSI)
Box 1 : Bay 7, 146 GB (Parallel SCSI)

Physical Drives Attached to Port 2 Box 1 : Bay 8, 146 GB (Parallel SCSI)
Box 1 : Bay 9, 146 GB (Parallel SCSI)
Box 1 : Bay 10, 146 GB (Parallel SCSI)

Online Spare Drive(s) None

-> What can i do to have one??
I don't find this option in ACU.

-> If i don't have a spare, if i take off a drive will i lost data???

-> Another tecnical question.
When I create the Logical Drive can i know what physical drive is involved?

Re: Storage MSA500 - RAID 5

Uwe Zessin — Thu, 07 Aug 2008 18:49:35 GMT

> Online Spare Drive(s) None

Do you have created a Logical Drive, yet?

I'm not deeply familiar with the MSA500, but maybe you can only define one when you have created at least one Logical Drive.

-> If i don't have a spare, if i take off a drive will i lost data???

A spare drive does not protect your data from a disk failure!

The protection is part of a Logical Drive created in RAID1, RAID5 or RAID6/ADG (Advance Data Guarding).

Once the RAID-initialization is complete and if a physical drive fails, the controller will 'take' a spare drive and assign it to the 'disk drive array'(see below). It will then reconstruct lost data and redundancy information and store it on the former spare drive.

-> Another tecnical question.
>When I create the Logical Drive can i know what physical drive is involved?

Before you do that, you must create a 'disk drive array'. This is where you define which physical drives are involved.
Next, you can create one or more 'Logical Drives' within the 'array'. This is also the time when you define the RAID-level.
All data you store will be automatically spread across all physical drives within the array.

Re: Storage MSA500 - RAID 5

BiancaP. — Thu, 07 Aug 2008 19:50:29 GMT

Thank you ! You really help me!!!

I already have a array and logical drives configurated.

I find that to configure a spare is in the Wizard Configuration -> Spare Configuration. But i don't have the Spare Configuration option in the Wizard Configuration.
Maybe is because my array is almost full ???

MSA500 G2 Controller in M57TLYPN8H
Parallel SCSI Array A

146 GB Parallel SCSI Drive at Box 1 : Bay 1
146 GB Parallel SCSI Drive at Box 1 : Bay 2
146 GB Parallel SCSI Drive at Box 1 : Bay 3
146 GB Parallel SCSI Drive at Box 1 : Bay 4
146 GB Parallel SCSI Drive at Box 1 : Bay 5
146 GB Parallel SCSI Drive at Box 1 : Bay 6
146 GB Parallel SCSI Drive at Box 1 : Bay 7
146 GB Parallel SCSI Drive at Box 1 : Bay 8
146 GB Parallel SCSI Drive at Box 1 : Bay 9
146 GB Parallel SCSI Drive at Box 1 : Bay 10

Logical Drive 1 (129998 MB, RAID 5 )
Logical Drive 2 ( 5000 MB, RAID 5 )
Logical Drive 3 ( 39999 MB, RAID 5 )
Logical Drive 4 ( 99999 MB, RAID 5 )
Logical Drive 5 ( 30998 MB, RAID 5 )
Logical Drive 6 ( 11000 MB, RAID 5 )
Logical Drive 7 ( 39999 MB, RAID 5 )
Logical Drive 8 ( 49999 MB, RAID 5 )
Logical Drive 9 ( 49999 MB, RAID 5 )
Logical Drive 10 ( 49999 MB, RAID 5 )
Logical Drive 11 ( 10000 MB, RAID 5 )
Logical Drive 12 ( 10000 MB, RAID 5 )
Logical Drive 13 ( 10000 MB, RAID 5 )
Logical Drive 14 ( 39999 MB, RAID 5 )
Logical Drive 15 ( 99999 MB, RAID 5 )
Logical Drive 16 ( 10000 MB, RAID 5 )
Logical Drive 17 ( 49999 MB, RAID 5 )
Logical Drive 18 ( 5000 MB, RAID 5 )
Logical Drive 19 ( 27998 MB, RAID 5 )
Logical Drive 20 ( 12000 MB, RAID 5 )
Logical Drive 21 ( 30998 MB, RAID 5 )
Logical Drive 22 ( 19997 MB, RAID 5 )
Logical Drive 23 ( 10000 MB, RAID 5 )
Logical Drive 24 ( 5000 MB, RAID 5 )
Logical Drive 25 ( 10000 MB, RAID 5 )
Logical Drive 26 ( 10000 MB, RAID 5 )
Logical Drive 27 ( 49999 MB, RAID 5 )
Logical Drive 28 ( 14997 MB, RAID 5 )
Logical Drive 29 ( 49999 MB, RAID 5 )
Logical Drive 30 ( 29998 MB, RAID 5 )
Logical Drive 31 (114997 MB, RAID 5 )
Logical Drive 32 (132125 MB, RAID 5 )

Any help ???

>>All data you store will be automatically spread across all physical drives within the array.

Ok... so i can't know where is the data right? (what disk is it). The controller that choose where put the data???

Re: Storage MSA500 - RAID 5

TTr — Thu, 07 Aug 2008 20:34:44 GMT

> But i don't have the Spare Configuration option in the Wizard Configuration.

That's because there are NO free drives available. You already used them all in your raid5 Array A.

> Ok... so i can't know where is the data right?

Each of the 32 logical drives is spread up on each and every one of the 10 drives using raid5 striping. You have no control over this.

One other thing I noticed. In your previous reply, you listed

> Physical Drives Attached to Port 1
> Box 1 : Bay 1, 146 GB (Parallel SCSI)
> Box 1 : Bay 2, 146 GB (Parallel SCSI)
> Box 1 : Bay 3, 146 GB (Parallel SCSI)
> Box 1 : Bay 4, 146 GB (Parallel SCSI)
> Box 1 : Bay 5, 146 GB (Parallel SCSI)
> Box 1 : Bay 6, 146 GB (Parallel SCSI)
> Box 1 : Bay 7, 146 GB (Parallel SCSI)

> Physical Drives Attached to Port 2
> Box 1 : Bay 8, 146 GB (Parallel SCSI)
> Box 1 : Bay 9, 146 GB (Parallel SCSI)
> Box 1 : Bay 10, 146 GB (Parallel SCSI)

Port 1 in the MSA500 has 7 drives attached to it and port 2 has only 3 drives. This creates and I/O imbalance inside the MSA500. Ideally with 10 drives you should have plugged 5 drives in bays 1-5 and 5 drives in bays 8-12. You can correct this but you should wait until you become more familiar with the array.

Re: Storage MSA500 - RAID 5

BiancaP. — Thu, 07 Aug 2008 20:39:52 GMT

Thanks!!!! =)