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10 replies Latest Post - ‏2014-03-17T14:15:04Z by Sriram_Iyer_1988
SriramIyer-StorageSSR
SriramIyer-StorageSSR
10 Posts
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Pinned topic How does Storwize V7000 provide hot spare coverage

‏2012-08-29T07:29:02Z |
Hi,

We have V7000 setup with
1) 35nos. 600GB SAS drives
2) 3nos. mdisks each with 11 member drives (mdisk creation was done thru CLI since GUI does not allow beyond 8 HDDs in a mdisk). These 3nos. mdisk form a storage pool.
3) remaining 2nos. HDDs have been configured as spare.

We continuously get the following warning messages :-

"Array/Mdisk 17 not protected by sufficient spares"
Unable to figure out why this message keeps coming since we have configured 2 spares and as per v7k theory all spares are global spares.

Also spare goal all mdisk is 1

Any input will be greatly appreciated. Storage is in production now.

Attached GUI pics for refernce

Thanks
Sriram Iyer
Updated on 2012-09-07T07:52:08Z at 2012-09-07T07:52:08Z by SriramIyer-StorageSSR
  • TMasteen
    TMasteen
    279 Posts
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    Re: How does Storwize V7000 provide hot spare coverage

    ‏2012-08-29T19:25:32Z  in response to SriramIyer-StorageSSR
    Take a look at this V7000 Redbook
    In Chapter 7.1.2 there is an explaination about presets and spares in a chain.
  • SriramIyer-StorageSSR
    SriramIyer-StorageSSR
    10 Posts
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    Re: How does Storwize V7000 provide hot spare coverage

    ‏2012-08-30T05:37:27Z  in response to SriramIyer-StorageSSR
    I went through that section of redbook. It seems v7000 allocates spares on chain basis.

    So the reason for "array/mdisk not protected by sufficient spares" message could be spares are in a different chain and my mdisk is in another chain.
    • SriramIyer-StorageSSR
      SriramIyer-StorageSSR
      10 Posts
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      Re: How does Storwize V7000 provide hot spare coverage

      ‏2012-09-07T07:48:27Z  in response to SriramIyer-StorageSSR
      v7000 does provide hot spare coverage on chain basis.
      As soon as I provisioned a spare drive in the chain containing the mdisk reporting "insufficient spare" issue got resolved.
      To summarize :
      1) The 5nos. expansions below V7000 control enclosure form chain 1. These expansions are connected to node canister SAS port 1.
      2) The 4nos. expansions above V7000 control enclosure plus V7000 control enclosure form chain 2. These expansions are connected to node canister SAS port 2.

      So, spare HDD in chain 2 cannot provide protection to mdisk in chain 1.
      Ensure sufficient spares are configured in both the chains.

      Thanks
  • SriramIyer-StorageSSR
    SriramIyer-StorageSSR
    10 Posts
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    Re: How does Storwize V7000 provide hot spare coverage

    ‏2012-09-07T07:52:08Z  in response to SriramIyer-StorageSSR
    ensure spare drives are provisioned in both the chains
    • JamesI
      JamesI
      3 Posts
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      Re: How does Storwize V7000 provide hot spare coverage

      ‏2014-03-17T02:49:42Z  in response to SriramIyer-StorageSSR

      Hi, how may I ask did you actually do this?  Via the CLI?  If so, what command?

      Thanks

      • Sriram_Iyer_1988
        Sriram_Iyer_1988
        3 Posts
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        Re: How does Storwize V7000 provide hot spare coverage

        ‏2014-03-17T08:52:10Z  in response to JamesI

        Hi Jamesl, please clarify what information do u want..

        Are u looking for commands for spare creation or mdisk creation ?

        Thanks

        Sriram Iyer

        • JamesI
          JamesI
          3 Posts
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          Re: How does Storwize V7000 provide hot spare coverage

          ‏2014-03-17T09:14:14Z  in response to Sriram_Iyer_1988

          Hi Sriram,

          Thanks for your reply.  I know how to create mdisks via CLI. 

          I have set a couple disks as spares in the GUI - but get the same error occurring as per the messages in this post.

          I need to set a drive as a hotspare for all mdisks (all same size drives) which I assume I do via the CLI but don't know the command to do this.

          Cheers

          • Sriram_Iyer_1988
            Sriram_Iyer_1988
            3 Posts
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            Re: How does Storwize V7000 provide hot spare coverage

            ‏2014-03-17T09:45:40Z  in response to JamesI

            Hi Jamesl

            Since the storage has only 1 type of disk, u need to check the chain diagram only for resolving the issue..

            Most probably your mdisk throwing the "insufficient spare message" is in one chain and both your spare disks are in other chain..

            Would u mind sharing the snap file of V7000 for better clarity.. ?

            Thanks

            Sriram Iyer

            • JamesI
              JamesI
              3 Posts
              ACCEPTED ANSWER

              Re: How does Storwize V7000 provide hot spare coverage

              ‏2014-03-17T10:38:50Z  in response to Sriram_Iyer_1988

              Hi,

              I should be more specific, there are 2 types of disks - 300GB SAS and 200GB SSD's. There is one control and one expansion enclosure. I have several Mdisks and pools created, SAS and SSD are spread over both enclosures. Need to assign 1 x SAS disk (in control enclosure slot 24) and 1 x SSD disk (in expansion enclosure slot 24) as hot spares for their respective disk type for all Mdisks. Setting as spare in GUI I get this message. Don't know how to tell it to be part of what I'm assuming is chain #1 (as only 1 expansion enclosure)

              Thanks

              • Sriram_Iyer_1988
                Sriram_Iyer_1988
                3 Posts
                ACCEPTED ANSWER

                Re: How does Storwize V7000 provide hot spare coverage

                ‏2014-03-17T14:15:04Z  in response to JamesI

                Hi Jamesl

                You can get chain details from GUI or command "lssasfabric".

                In  your case we have 1 controller and 1 expansion. If properly cabled as per installation guide then expansion will be in chain 1 and controller will be in chain 2.

                Since you have SAS disks and SSD disks spread across both enclosures, you will need to assign 1xSAS and 1xSSD as spare from controller and 1xSAS and 1xSSD as spare from expansion.

                This will ensure both types of spares are available in both chains and mdisks will no longer report "insufficient spares" message.

                Things would have been easier for you had all SSDs been in controller and all SAS disks been in expansion. In that case 1 spare from each enclosure would have been sufficient.

                Thanks

                Sriram Iyer

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