Topic
5 replies Latest Post - ‏2013-06-07T06:43:52Z by tresnta.sis
tresnta.sis
tresnta.sis
3 Posts
ACCEPTED ANSWER

Pinned topic Optimal configuration M5015

‏2013-05-18T12:21:45Z |

Hello,

 

I have an IBM server 3650 M2 with Megaraid M5015 with SLES 11 SP1. We are having performance problems, it seems that are problems with i/o subsystem, but not sure. We have same configuration on other environment with vmware or Intel server and is working perfect, only difference is hardware

At this moment we are upgrading to latest versions of firmwares, drivers, SLES SP2... but we want to optimize this server for optimal performance, because is a crtical server with a database and about 500 concurrent users.

M5015 has 2 SAS (RAID 1) disk with a hotspare  and 5 SSD (RAID 5) disks with hotspare, but our configuracion of virtual drive has:

- Write policy:  Write back

- Read policy: no read ahead 

- Disk Cache policy: False

- io policy: direct

 

We have applied some SLES recommendation about OS, and upgraded to SP2

IBM support recommenden to upgrade latest firmware/drivers, but they asked that performance problems are not supported by IBM? Anybody can help to  give some recommendations or best practices for optimal configuration with megaraid M5015 for these RAIDs? Any tools to make some performance test and compare result before and after?

Second question, what is the battery life? 

 

Thanks

 

Updated on 2013-05-20T17:40:53Z at 2013-05-20T17:40:53Z by tresnta.sis
  • BenjaminD
    BenjaminD
    2 Posts
    ACCEPTED ANSWER

    Re: Optimal configuration M5015

    ‏2013-05-29T06:33:02Z  in response to tresnta.sis

    Hi,

    We use this to tune our system. http://mycusthelp.info/LSI/_cs/AnswerDetail.aspx?inc=8196

    Also check your write policy and your BBU status

    Regards

  • dj.muysson
    dj.muysson
    9 Posts
    ACCEPTED ANSWER

    Re: Optimal configuration M5015

    ‏2013-05-29T16:02:02Z  in response to tresnta.sis

    Can you elaborate on the type of performance issue you are running into?

    One of the most critical things with RAID adapters is to ensure the battery is still functional. If the battery is marked as faulty (either by old firmware marking it prematurely, or the battery being genuinely bad) the controller will switch to write-through mode. This can drastically cut performance on what seemed to be a working server.

    Given the age of the server, and if the M5015 has never had a battery replacement, I would expect the battery to be EOL.

    If your battery is OK, what stripe size did you use with the R5 array? Depending on the IO size the application uses, this could cause significant loss due to R5 parity recalculation under some situations.

     

    • tresnta.sis
      tresnta.sis
      3 Posts
      ACCEPTED ANSWER

      Re: Optimal configuration M5015

      ‏2013-05-31T18:54:57Z  in response to dj.muysson

      Hello,

       

      First of all thanks for your anwsers.

      This server is a database server with Linux SLES 11. Battery appears as optimal, with MSM, and was replaced 1.5 years ago. Our question is if lifetime of this battery is 1 year or 3 years? Which is the replace period? write policy is write back with bbu?

      In MSM appears some errors  with message "unexpected sense" but I don't know what is the problem, and exactly what is this message...

      This server is in maintenance mode and we upgraded all firmware, bios...

      This server has 5 ssd disk withous performance key, what is estimated iops for sas 50GB disks in this environment? Advanced performance key is really a great improvement?

       

       

      And about 

      http://mycusthelp.info/LSI/_cs/AnswerDetail.aspx?inc=8196

      All proposed modifications must be executed? How increase performance with this configurations?

       

      And Finally I use bonnie, tot test in this linux server the performance, what is the best utility to make great performance tests and make comparisons?

       

      Thanks for all

       

      • dj.muysson
        dj.muysson
        9 Posts
        ACCEPTED ANSWER

        Re: Optimal configuration M5015

        ‏2013-06-03T12:40:01Z  in response to tresnta.sis

        The lifetime of the battery is usually around 2.5-3 years, but I've seen them last as little as 1.5 years in a few cases.

        Write back with BBU is best for production environments. For testing, forcing Write Back can be used to ensure WB is truly enabled during a performance test.

        What type of SSD drive are you using? I have had issues with non-IBM drives on the M5015 before, and your comment about the 'unexpected sense' messages is concerning.

        Do you know what stripe size you are using on the array?

        The Advanced Performance Key enables a number of features, but the only one you would really use in this case is FastPath. FastPath requires both the performance key as well as the FastPath software installed on the OS.

         

        Oh, and IBM just released their SSD Wear Guage CLI tool which can be used to determine the wear level & remaining % of their SSD drives. If you are using the 50GB IBM SSD's, they have been around for a while and may be nearing the end of their life.

        Windows: http://www.ibm.com/support/entry/portal/docdisplay?lndocid=MIGR-5090921&brandind=5000008&myns=x008&mync=E

        Linux: http://www-947.ibm.com/support/entry/portal/docdisplay?lndocid=MIGR-5090923&brandind=5000008&myns=x008&mync=E

        Updated on 2013-06-03T13:04:50Z at 2013-06-03T13:04:50Z by dj.muysson
        • tresnta.sis
          tresnta.sis
          3 Posts
          ACCEPTED ANSWER

          Re: Optimal configuration M5015

          ‏2013-06-07T06:43:52Z  in response to dj.muysson

          Finally we have upgraded to SLES 11 SP2 and now we are using SLES drivers, not IBM drivers and all seems to work perfect

           

          Thanks for all