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3 replies Latest Post - ‏2007-07-06T10:38:37Z by tech-hunger
tech-hunger
tech-hunger
9 Posts
ACCEPTED ANSWER

Pinned topic Load Balancing on VIO servers

‏2007-06-01T14:49:45Z |
Hi,

I have got a pair of VIO servers (VIO1 & VIO2)each having 3 SEAs (shared ethernet adapters). The CPU allocation for each of the VIO server is 0.5 units. Number of client that share these 2 VIO servers is 4.

For all the 3 SEAS I have configured VIO1 as primary and VIO2 as backup.

The clients (using virtual ethernet) use SEA2 and SEA3 a lot so I thought to distribute the load between the 2 VIO servers by assigning VIO2 as the primary server for SEA3. So that VIO1 is not loaded to handle traffic from both the SEAS.

Is this approach ok to distribute the load across 2 vio servers. Does it help at all??

Similarly for Vscsi the clients have disks coming from both the VIO servers and they are mirrored on the client. Is there anyway I can instruct the client to use a specific copy so that I can configure some clients to have scsi of VIO1 to be used and rest of them to use scsi of VIO2, again to distribute the load. I dont think there is anyway you can ask AIX to look at a specific copy , but with VIO is there any other way we can achieve this objective.

Thanks in advance

Updated on 2007-07-06T10:38:37Z at 2007-07-06T10:38:37Z by tech-hunger
  • esv
    esv
    28 Posts
    ACCEPTED ANSWER

    Re: Load Balancing on VIO servers

    ‏2007-06-28T10:50:22Z  in response to tech-hunger
    > Hi,
    >
    > I have got a pair of VIO servers (VIO1 & VIO2)each
    > having 3 SEAs (shared ethernet adapters). The CPU
    > allocation for each of the VIO server is 0.5 units.
    > Number of client that share these 2 VIO servers is
    > 4.
    >
    > For all the 3 SEAS I have configured VIO1 as primary
    > and VIO2 as backup.
    >
    > The clients (using virtual ethernet) use SEA2 and
    > SEA3 a lot so I thought to distribute the load
    > between the 2 VIO servers by assigning VIO2 as the
    > primary server for SEA3. So that VIO1 is not loaded
    > to handle traffic from both the SEAS.
    >
    > Is this approach ok to distribute the load across 2
    > vio servers. Does it help at all??
    >

    Yes, I just attended a webcast where it specifies the more IP traffic on a VIO server the more CPU it uses, while you have 2 VIO servers the only method that I know to load balance the network traffic on the VIO servers is to configure the VIO client in such a way to prefer one over the other, if you are using the Virtual LAN with failover (a single VLAN on both VIO servers and a private VLAN between the VIO Servers to send the keep alives), then you have to configure each VIO server to be the preferred one for each SEA adapter.
    > Similarly for Vscsi the clients have disks coming
    > from both the VIO servers and they are mirrored on
    > the client. Is there anyway I can instruct the client
    > to use a specific copy so that I can configure some
    > clients to have scsi of VIO1 to be used and rest of
    > them to use scsi of VIO2, again to distribute the
    > load. I dont think there is anyway you can ask AIX to
    > look at a specific copy , but with VIO is there any
    > other way we can achieve this objective.

    Well, since you are mirroring the data on the client, it is using both drives concurrently it favors one over the other on reads, but it writes on both.

    If you were using external storage to the VIO servers where you can use a single LUN attached to both VIO Servers and then make it visible to the VIO Client, then check the chpath command to raise the priority of one path over the other.

    I believe the lesser the value, the higher the priority, but that is just a hunch.

    check the following command output .......

    best regards,
    Enrique.

    prompt> lspath -F "name parent connection"
    hdisk6 vscsi1 870000000000

    prompt> lspath -A -l hdisk1 -p vscsi1 -w 850000000000 -DO -a priority
    #priority
    1

    prompt> chpath
    chpath: 0514-502 Usage error
    Flag or parameter information is missing: -l.

    Usage:
    chpath -s OpStatus -l Name -p ParentName -w ConnectionLocation
    chpath -l Name -p ParentName -w ConnectionLocation -P
    -a Attribute=Value -a Attribute=Value...
    chpath -h
    >
    > Thanks in advance
    >
    >

    yw
  • nswaus
    nswaus
    3 Posts
    ACCEPTED ANSWER

    Re: Load Balancing on VIO servers

    ‏2007-07-04T10:52:51Z  in response to tech-hunger
    If you are using lvm mirroring, look at the -d flag on chlv / mklv. You can set a Parallel write with sequential read policy, where reads are always done from the first mirrored copy if its available. Obviously, you need to create your lvm mirrors correctly so as to get the reads balanced over the 2 vios.
    • tech-hunger
      tech-hunger
      9 Posts
      ACCEPTED ANSWER

      Re: Load Balancing on VIO servers

      ‏2007-07-06T10:38:37Z  in response to nswaus
      Hurray.... Finally someone has replied to my thread.

      Thanks to both Enrique Sanchez,nswaus. Now I am confident of going with that approach in regards to networking, I was waiting for someone to confirm that my approach was right. Coming to the disk part, since currently I am using internal disk, but very soon I will be using SAN then I will also try to implement the priorites on the client.

      Cheers