Friday, 18 November 2011

Dell Powervault MD3200i Brief Installation Walkthrough Notes with VMware vSphere Hosts


1: Rack Installation

2: Installation of software onto laptop / server

Download the MDSeriesStorageSoftware_....iso from Dell and mount to DVD-drive.
Either autorun or execute the md_launcher.exe from the DVD

Follow the prompts to run a full install (Core Software and Management Station) of the MD Storage Software



Core Software: The core software features include the software necessary to enable management and host operations of MD Storage Arrays
Management Station: Installs the MD Storage Manager software to configure, manage, and monitor a storage array.

3: Connections to Power Source

Connect the two power supplies to power sockets (ideally either across two different UPSes, or two different power distribution units)

4: Initial Configuration of IP Addressing

Temporarily connect the management ports and iSCSI ports into one switch on one VLAN, along with laptop with MD Storage Software installed.

Give the laptop an address which can access the default controller static IP addresses:

Controller 0: IP: 192.168.128.101 Subnet Mask: 255.255.255.0
Controller 1: IP: 192.168.128:102 Subnet Mask: 255.255.255.0

*Note that the above default static IP addresses are automatically configured in the absence of a DHCP server

For completeness the default static IP addresses for the iSCSI ports are set to the following:

Controller 0, Port 0: IP: 192.168.130.101 Subnet Mask: 255.255.255.0 Port: 3260
Controller 0, Port 1: IP: 192.168.131.101 Subnet Mask: 255.255.255.0 Port: 3260
Controller 0, Port 2: IP: 192.168.132.101 Subnet Mask: 255.255.255.0 Port: 3260
Controller 0, Port 3: IP: 192.168.133.101 Subnet Mask: 255.255.255.0 Port: 3260

Controller 1, Port 0: IP: 192.168.130.102 Subnet Mask: 255.255.255.0 Port: 3260
Controller 1, Port 1: IP: 192.168.131.102 Subnet Mask: 255.255.255.0 Port: 3260
Controller 1, Port 2: IP: 192.168.132.102 Subnet Mask: 255.255.255.0 Port: 3260
Controller 1, Port 3: IP: 192.168.133.102 Subnet Mask: 255.255.255.0 Port: 3260

Run the ‘Modular Disk Configuration Utility’ from All Programs > Dell > Modular Disk Configuration Utility

  
And follow the prompts to ‘Configure Modular Disk Storage Array’
The tool can automatically discover the array and can be used to configure name, password, management port IP addresses, iSCSI host port IP addresses…

Configure both management ports to put them on the desired management network
The iSCSI ports do not need to be route-able and could be left on the defaults

5: MD3200i Connections to Network Switches

Connect the iSCSI ports on the RAID controllers across two switches for resilience
RAID Controller 0: Port 0 and Port 2 connect to switch 1
RAID Controller 0: Port 1 and Port 3 connect to switch 2
RAID Controller 1: Port 0 and Port 2 connect to switch 1
RAID Controller 1: Port 1 and Port 3 connect to switch 2

Connect the Management ports on RAID Controllers 0 and 1 to either switches 1 and 2 respectively, or could put these on a separate switch if there is a requirement to save ports on the iSCSI stack.

See diagram below:


*Note that iSCSI Subnet 1 and 3 only exist on switch 1, and iSCSI Subnet 2 and 4 only exist on switch 2, so there is no need for iSCSI traffic to travel from switch-to-switch or module-to-module

6: Configure Alerts, RAID and host groups

Run the ‘Modular Disk Storage Manager Client’ from All Programs > Dell > MD Storage Manager


Right-click the discovered Storage Array > Manage Storage Array

The interface is quite intuitive and I am going to skip details here
Main things to configure are:

a: Alerts
b: RAID setup – the MD3200i has 12 disks with various options to setup the RAID
c: Volumes to be presented to VMware Hosts
d: Host Groups – configure access for VMware Hosts using iSCSI identifiers

*Note - my preference would be to configure the 12 disks as 1x10 disk RAID 6 with 2 hot spares, as this can tolerate 4 disk failures but loses a 3rd of the raw disk space. Some other options if do not want to lose so much raw space are 2x6 disk RAID 5 or a 1x12 disk RAID 6

7: VMware Host Setup

The MD3200i does support 4-way multipath, I would suggest to start with 2-way multipath and expand if the extra throughput is really required. See an example configuration for two hosts across two switches in the below diagram:


The iSCSI paths should be configured using round robin. Paths are active to one controller and standby to the other.

17 comments:

  1. why not configure 4 nics per server with all 4 iSCSI subnets?

    Is it not needed?

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  2. It is perfectly okay to configure 4 iSCSI NICs per host server across the 4 iSCSI subnets (which I have done in the past.) For most circumstances, the throughput afforded with 2-way MPIO is sufficient; but if the project demands 4-way MPIO, and the prerequisite host NICs and switch ports are available, then we must configure the 4-way MPIO. Dell's installation guide used a 2-way MPIO configuration. Cheers!

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  3. how did you cut up the hard disks? would you create just one disk group using RAID 5? And then one quorum volume and one CSV volume?

    ReplyDelete
    Replies
    1. Hello Anonymous, it all depends what you want to do with the MD3200i. If you are using it as iSCSI storage for virtual machines, I would recommend a 10 disk RAID 6 with two hot spares as this offers a high level of resilience, or a 12 disk RAID 6 is you cannot afford to lose two disks as hot spares. When you have your RAID setup in place, you can create LUNs of the desired size for whatever intended purpose. Cheers!

      Delete
  4. Hopefully you're still watching this post. We have an MD3200i on the way for our VM storage (currently using NexentaStor iSCSI, which is a bit flaky). Our infrastructure has two switches, one subnet per switch, so each host has 2 iSCSI ports, and the server hosting storage has 2 as well. With the MD3200i having 8 total ports, it's easy to see using 2 ports on each controller, with one to each subnet. What I don't understand is how/if it's possible to use the remaining 4 ports in a meaningful way (without adding more VLANs and physical NICs to each host). Is this possible, or are we just going to be using half the ports unless we add more subnets/NICs?

    Also, on a bit of a tangent, I'm trying to figure out LUN sizing with ESXi 5 on the MD3200i. The array will be one large virtual disk for RAID purposes, and there are about 100 VMs, mostly web servers. I know that the locking and contention issues have been improved, but I haven't seen a source that tells me what operations still cause these issues. Obviously I don't want to create one huge LUN/VMFS that has terrible performance, but I also don't want to have 30 small LUNs that I have to manage. Any advice on that?

    Thanks!

    ReplyDelete
    Replies
    1. Hi Anonymous,

      Yes, I am watching the comments - automatically get emailed whenever a new comment is published.

      On the first point, you have 4 iSCSI subnets, so you could configure host A in subnets 1 & 2, and host B in subnets 3 & 4. The ports on the MD32000 are not wasted in that way but shared between the hosts. Also remember that you will have 2 IPs in each subnet (1 IP per subnet per controller) but one path will be active and the other standby. Recommend checking the Dell documentation as it explains the reasoning behind it much better and with diagrams too (there is no need for iSCSI traffic to traverse any switch interconnect if configured correctly.)

      On the second point, the SCSI locking mainly occurs when a thin-provisioned server needs to be grown, or when a server is in snapshot mode and the delta needs to grown. It is indeed improved in VMFS5. As a very general rule of thumb, try to maintain datastores with no more than 10 VMs per datastore.

      Hope that helps. Cheers!

      Delete
    2. Thanks for the help, I think I have a better understanding of what's going on now. If I understand correctly, the cabling for the VM hosts remains the same as it is now, 1 cable to each SAN switch, and I'm just alternating the subnets being used on the iSCSI vmkernel ports to get rudimentary balancing across the 4 subnets on the MD unit, correct? In my environment, the switches don't have interconnects on the iSCSI VLAN, specifically because I wanted to make sure that everything was being set up correctly so that one switch going down didn't kill every path to a target.

      (BTW, Dell's diagrams on this would be much nicer if their cabling illustrations were consistent. I spent probably half an hour trying to tell that this is what I think they're doing in the deployment guide. Grr.)

      Delete
  5. HI,

    How would you configure this setuo with 3 Hosts, Thanks

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    Replies
    1. Hi TC,
      The easiest way for sure is to plug the 3 hosts directly into the MD3200i. Assuming 2 NICs for iSCSI on each host and a dual controller quad-port iSCSI MD3200i. Plug host 1 into port 0 on both controllers, host 2 into port 1 on both controllers, etc. Saves on switch ports and halves the number of cables used.
      Cheers!

      Delete
    2. Sorry, I forgot to mention we have already purchased two Switches for iscsi

      Delete
    3. Configure each port - 0,1,2,3 in its own subnet. Patch 0,1 into the top switch, patch 2,3 into the bottom switch. Do this for both controllers.

      The idea is that 2 subnets exist exclusively on the top switch, 2 subnets exist exclusively on the bottom switch (no need to traverse an interconnect - so effectively a dual fabric.)

      Patch your hosts accordingly into top and bottom switches (i.e. one host connection to top, one host connect to bottom for dual-path,) and configure to use the correct subnets (i.e. for dual-path: host 01 might use subnet 0,2, host 02 subnet 1,3, host 03 subnet 0,2, ... ; or for quad-path they can use subnets 0,1,2,3.)

      Hope that makes sense.

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    4. Thanks , much appreciated

      Delete
  6. Hi, i have a MD3200i with 2 4port controllers and 2 Hyper-V Servers with 2 Gbit iSCSI ports. On the MD3200i i use the default IPs on the Controllers. On the Servers i will put the following: Server1 iSCSI1=192.168.130.201, iSCSI2=192.168.131.201 / Server2 iSCSI1=192.168.132.201, iSCSI2=192.168.133.201

    When i configure the Dell Modular Disk Configuration Utility how will i assign the host ports to the controller ports?
    Can this works in active active mode?

    Thank you.

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  7. Is there a reason this cant all be done on the same subnet and than tieing the vmkernel ports to the physical nics?

    ReplyDelete
    Replies
    1. Hi Duhaas,

      There's no reason why you couldn't put the NICs all on the same subnet, but whether the MPIO would work properly is another question. If you're setting up a brand new box and have time, try it out in one subnet and see how it goes. The above follows information sourced from Dell's own MD3200i installation guide which uses different subnets and recommends that configuration.

      Cheers!
      VCosonok

      Delete
  8. Hi VCosonok,

    First I connected a laptop with IP 192.168.128.103 and the MDSU Configuration assistant can recognize the MD3200i Console 0 MNGT, also recognizes Console 1 MNGT.

    But when I try to go through the wizard and try to change the Name, Password and Console 0 MNGT IP address it does not save and says that

    Fails to connect Array Management port(s). Please verfiy and make sure that Management port, can be accessed. (error I have translated from German)

    Do you have any idea on this error ?

    Thanks,
    Kiran

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  9. I get the same error Kiran - did you work out what caused it?

    ReplyDelete