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M_Polyakov
1 Copper

RAID 5 (6+1) Pool on VNX 5300

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Hi! It's possible to create RAID 5 (6+1) pool on VNX5300 system? If possible, how i can do this? I can't find information about this in official documents.

Maybe i can create RAID 5 (6+1) over navisphere cli?

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8 Krypton

Re: Re: RAID 5 (6+1) Pool on VNX 5300

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The -rdrivecount field is important and is limited to the following values:

VNX OE for Block v31

================

RAID 5: 5

RAID 6: 8

RAID 1/0: 8

VNX OE for Block v32

================

RAID 5: 5, 9

RAID 6: 8, 16

RAID 1/0: 8

I can actually tell from the error message you received, that you are running VNX OE for Block v32:

[...]

Unsupported RAID drive count. The following values are supported for

RAID 5: 5, 9

[...]



If you were to compare the list above to the Unisphere interface, you would see that they match exactly the "RAID Type" pull down where it defines both the RAID Type and the size of the underlying private RAID Groups the system will (try to) create.



Keep in mind, that if you do want the private RAID Groups to be anything other than the given choices, then the right strategy would not be to provide all 32 drives as you have in your original command.  If you were to follow the logic explained in the following post and provided -rdrivecount 9 (you wouldn't be able to get the desired R5 (7+1) with -rdrivecount 5😞


https://community.emc.com/message/696115#696115


Then ran the following commands:


1) navisecccli -help


IMPORTANT: Verify that you are running at least naviseccli Revision 7.32+



2) navisecccli -h <SPA or SPB IP> storagepool -list -listinternal


This will list the private RAID Groups associated with each pool.



3) navisecccli -h <SPA or SPB IP> getrg -<engineering password>

You can then get the number of drives associated with the pRG's that you listed from the previous command.

You would see that it created the following underlying private RAID Group structures which you wouldn't want.  Again, this is if you were to run your original command providing all 32 drives:

3x R5 (8+1)

1x R5 (4+1)

Instead as explained in the post referenced above, the proper strategy if you insist on R5 (7+1) pRG structures would be instead to:

1) Create initial tier with 8 drives (selecting: -rdrivecount 9)

2) Expand tier with 8 drives at a time

EDIT: updated to cleanup formatting

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Sudheer71
6 Indium

Re: RAID 5 (6+1) Pool on VNX 5300

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Hello,

Please find the CLI guide on this link

https://mydocs.emc.com/VNX/relatedDocs.jsp?rd=RelatedDocs_1

EMC VNX Command Line Interface Reference for Block

You could add un-recommended (check best practices guide below) number of drives into a pool by over-riding the warning, however performance would be impacted

https://support.emc.com/docu42660_Applied_Best_Practices_Guide:_EMC_VNX_Unified_Best_Practices_for_P...


Regards,

Sudheer

M_Polyakov
1 Copper

Re: RAID 5 (6+1) Pool on VNX 5300

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Hi! Today i read this guide and try to create storage pool with next

command parameters:

"naviseccli -user admin -password P@ssw0rd -address 10.56.232.137

-scope 0 storagepool -create -disks 0_0_4 0_0_5 0_0_6 0_0_7 0_0_8

0_0_9 0_0_10 0_0_11 0_0_12 0_0_13 0_0_14 1_0_0 1_0_1 1_0_2 1_0_3 1_0_4

1_0_5 1_0_6 1_0_7 1_0_81_0_9 1_0_10 1_0_11 1_0_12 1_0_13 0_1_0 0_1_1

0_1_2 0_1_3 0_1_4 0_1_5 0_1_6 -rtype r_5 -rdrivecount 7 -skiprules"

But i receive next message:

The creation of storagepool did not succeed. The storagepool will not

be created.

Rule Messages:

Unsupported RAID drive count. The following values are supported for

RAID 5: 5, 9

So, unfortunately, i think that it's not possible create RAID 5 with

6+1 type parity disks...

On Mon, 26 Aug 2013 12:08:35 -0700

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8 Krypton

Re: RAID 5 (6+1) Pool on VNX 5300

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Try running that command but only specify 7 drives, see if that works. You can expand the pool later by adding 7 more drives but curious if it works by specifying 7 drives only.

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8 Krypton

Re: RAID 5 (6+1) Pool on VNX 5300

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Reading the CLI guide in a bit more detail and I think you can use the -rdrivecount 7 parameter but you don't have to. You have to create the pool with 7 drives only in order to get 6+1. When you create the pool and select only 7 drives the VNX will automatically create 6+1; no need to specify -rdrivecount. The -rdrivecount parameter comes into play in the following example. Let's say you want to create a pool (using CLI) that is using 8+1. If you don't use the -rdrivecount parameter the VNX will create two private RAID Groups; 4+1 and 3+1. That's where the -rdrivecount comes into play. If you create the same pool with the rdrivecount 9 the VNX will create one private RAID Group with 8+1

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M_Polyakov
1 Copper

Re: RAID 5 (6+1) Pool on VNX 5300

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Thank for the help, Ernes!

On Tue, 27 Aug 2013 07:18:37 -0700

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8 Krypton

Re: Re: RAID 5 (6+1) Pool on VNX 5300

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The -rdrivecount field is important and is limited to the following values:

VNX OE for Block v31

================

RAID 5: 5

RAID 6: 8

RAID 1/0: 8

VNX OE for Block v32

================

RAID 5: 5, 9

RAID 6: 8, 16

RAID 1/0: 8

I can actually tell from the error message you received, that you are running VNX OE for Block v32:

[...]

Unsupported RAID drive count. The following values are supported for

RAID 5: 5, 9

[...]



If you were to compare the list above to the Unisphere interface, you would see that they match exactly the "RAID Type" pull down where it defines both the RAID Type and the size of the underlying private RAID Groups the system will (try to) create.



Keep in mind, that if you do want the private RAID Groups to be anything other than the given choices, then the right strategy would not be to provide all 32 drives as you have in your original command.  If you were to follow the logic explained in the following post and provided -rdrivecount 9 (you wouldn't be able to get the desired R5 (7+1) with -rdrivecount 5😞


https://community.emc.com/message/696115#696115


Then ran the following commands:


1) navisecccli -help


IMPORTANT: Verify that you are running at least naviseccli Revision 7.32+



2) navisecccli -h <SPA or SPB IP> storagepool -list -listinternal


This will list the private RAID Groups associated with each pool.



3) navisecccli -h <SPA or SPB IP> getrg -<engineering password>

You can then get the number of drives associated with the pRG's that you listed from the previous command.

You would see that it created the following underlying private RAID Group structures which you wouldn't want.  Again, this is if you were to run your original command providing all 32 drives:

3x R5 (8+1)

1x R5 (4+1)

Instead as explained in the post referenced above, the proper strategy if you insist on R5 (7+1) pRG structures would be instead to:

1) Create initial tier with 8 drives (selecting: -rdrivecount 9)

2) Expand tier with 8 drives at a time

EDIT: updated to cleanup formatting

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8 Krypton

Re: RAID 5 (6+1) Pool on VNX 5300

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Was your question answered correctly? If so, please remember to mark your question Answered when you get the correct answer and award points to the person providing the answer. This helps others searching for a similar issue.

glen

M_Polyakov
1 Copper

Re: RAID 5 (6+1) Pool on VNX 5300

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Hi! Thanks all for answers. Correct answer that supported rdrivecount is 5(4+1) or 9(8+1). No other count of drives available for selection. We added 28 SAS disks to Pool with rdrive count 8+1 and summary size of Pool is 15014.268 Gb.This is what we need. Thank you guys, you are really helped.

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8 Krypton

Re: Re: RAID 5 (6+1) Pool on VNX 5300

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Correct, those are the only choices as noted above.  When you added the 28 drives, as suggested above again in order to get your desired: R5 (6+1) pRG's.  Did you also create and then expand the tier in increments of 7 drives at a time (while also selecting -rdrivecount 9)?

If not and you added all at once, then if you run the commands above, you would actually have created the following underlying pRG's by also following the logic as noted in a separate post that was referenced above:

2x R5 (8+1)

1x R5 (9+1)

(If I wanted I could also answer on my own if I fired up the capacity calculator and compare to the final usable capacity you noted below... meh... easier to ask}

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