Posts Tagged ‘active’

Force10 MXL: Firmware Upgrade

March 19, 2015

Uploading new firmware image

MXL switches keep two firmware images – A and B. You can set either one of them to be active. Use the following command to list firmware version of all stack members and see which one is active:

 # show boot system stack-unit all

mxl_firmware

To upload firmware you will need a TFTP server. You can use TFTPD64 (also called TFTPD32), which can be downloaded from Philippe Jounin page here .

If the active firmware image is in A, upload new firmware to B. You’ll also be asked if you want to upload firmware to all switches in the stack.

# upgrade system tftp://10.0.0.1/FTOS-XL-9.5.0.0P2.bin b:

firmware_upload

At the time of upgrade the latest version was 9.7. This version was 2 weeks old and wasn’t recommended for use in production. Version 9.6 had a major bug. As a result version 9.5SP2 was chosen for the upgrade.

Double-check that new firmware has been successfully distributed to all switches:

 # show boot system stack-unit all

check_firmware

Backing up startup config

Make sure you do not miss this step. If something goes wrong and switch looses its config, you’ll have to recreate all configuration from scratch. Imagine the consequences.

# copy start tftp://10.0.0.1/MXL_01.01.15.conf

Reloading the stack

Once firmware is uploaded and config is saved, reload the stack. Be mindful that it’s a disruptive procedure and all links connected to the stack will go down. A reboot shouldn’t take more than a couple of minutes, but make sure you do that after hours.

# conf t
# boot system stack-unit all primary system b:
# exit
# copy run start
# reload

Confirm that the active firmware image is now B. And that concludes the switch stack upgrade.

firmware_upgraded

 

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Windows MPIO with IBM storage

September 17, 2012

IBM mid-range storage systems (like DS3950) work in active/passive mode. It means that access to each LUN is given through one controller, in constrast to active/active storage where data between host and two controllers can flow in round-robin fashion. So redundant path here is used only as a failover. Software which provides this failover functionality is called Multipath I/O (MPIO) and has implementations for all operating systems. I’ll desribe how to configure MPIO version for Windows.

Installation

Prior to Windows Server 2008, Microsoft didn’t have its own MPIO implementation and MPIO was distributed with IBM DS Storage Manager product. Now you can install MPIO from “Feautures” sub-menu of Windows Server 2008 Server Manager. After installation is complete you will find MPIO configuration options under Control Panel and in Administrative Tools.

IBM storage works well with default Windows MPIO implementation, however it’s recommended to install IBM MPIO (device-specific module) from Storage Manager installation bundle. In my case MPIO installation file was called SMIA-WSX64-01.03.0305.0608.

Enable multipathing

Initially you will see two hard drives for each LUN in Device Manager. You can enable MPIO for particular hardware ID (in other words, storage system) on Discover Multi-Paths tab of MPIO control panel. You can’t do that with LUN granularity. After you add selected devices and reboot, you will see them on “MPIO Devices” tab. Now each LUN will be seen as a single hard drive in Device Manager.

Configure preferred path

MPIO supports several load-balancing policies, which are configured on a LUN basis from MPIO tab of a hard drive in Device Manager. As a Load Balance Policy select Fail Over Only. Then for each path select which is Active/Optimized and which is a Standby path. Also make active path Preferred, so that after failover it failbacks to it.

Don’t be confused by iSCSI on the figure. It’s the same for pure FC. It’s just for reference.

Check configuration

When you configure active and passive paths you assume that first path listed is to controller A and second path is to controller B. But, in fact, there is no indication of that from the configuration page and you can neither confirm nor deny it. The only ID you see is adapter ports but they don’t even map to the actual ports on HBAs.

To be able to check your configuration you need to install IBM SMdevices utility which comes with IBM DS Storage Manager. Run DS SM installation and go for Custom Installation. There you need to check only the Utilities part. In SMdevices output you can see which path is preferred for this LUN and if it’s configured as active (In Use):

C:\Program Files\IBM_DS\util>SMdevices
IBM System Storage DS Storage Manager Devices
. . .
\\.\PHYSICALDRIVE1 [Storage Subsystem ITSO5300, Logical
Drive 1, LUN 0, Logical Drive ID
<600a0b80002904de000005a246d82e17>, Preferred Path
(Controller-A): In Use]

References

The best reference I found on that topic is IBM Midrange System Storage Hardware Guide (SG24-7676-01), from p.453: DS5000 logical drive representation in Windows Server 2008. As well as Installing and Configuring MPIO guide from Microsoft.

NetApp Active/Active Cabling

October 9, 2011

Cabling for active/active NetApp cluster is defined in Active/Active Configuration Guide. It’s described in detail but may be rather confusing for beginners.

First of all we use old DATA ONTAP 7.2.3. Much has changed since it’s release, particularly in disk shelves design. If documentation says:

If your disk shelf modules have terminate switches, set the terminate switches to Off on all but the last disk shelf in loop 1, and set the terminate switch on the last disk shelf to On.

You can be pretty much confident that you won’t have any “terminate switches”. Just skip this step.

To configuration types. We have two NetApp Filers and four disk shelves – two FC and two SATA. You can connect them in several ways.

First way is making two stacks (formely loops) each will be built from shelves of the same type. Each filer will own its stack. This configuration also allows you to implement multipathing. Lets take a look at picture from NetApp flyer:

Solid blue lines show primary connection. Appliance X (AX) 0a port is connected to Appliance X Disk Shelf 1 (AXDS1) A-In port, AXDS1 A-Out port is connected to AXDS2 A-In port. This comprises first stack. Then AY 0c port is connected to AYDS1 A-In port, AYDS1 A-Out port is connected to AYDS2 A-In port. This comprises second stack. If you leave it this way you will have to fully separate stacks.

If you want to implement active/active cluster you should do the same for B channels. As you can see in the picture AX 0c port is connected to AYDS1 B-In port, AYDS1 B-Out port is connected to AYDS2 B-In port. Then AY 0a port is connected to AXDS1 B-In port, AXDS1 B-Out port is connected to AXDS2 B-In port. Now both filers are connected to both stacks and in case of one filer failure the other can takeover.

Now we have four additional free ports: A-Out and B-Out in AXDS2 and AYDS2. You can use these ports for multipathing. Connect AX 0d to AXDS2 B-Out, AYe0d to AXDS2 A-Out, AX 0b to AYDS2 A-Out and AY 0b to AXDS2 B-Out. Now if disk shelf module, connection, or host bus adapter fails there is also a redundant path.

Second way which we implemented assumes that each filer owns one FC and one SATA disk shelf. It requires four loops instead of two, because FC and SATA shelves can’t be mixed in one loop. The shortcoming of such configuration is inability to implement multipathing, because each Filer has only four ports and each of it will be used for its own loop.

This time cabling is simpler. AX 0a is connected to AXDS1 A-In, AX 0b is connected to AYDS1 A-In, AY 0a is connected to AXDS2 A-In, AY 0b is connected to AYDS2 A-In. And to implement clustering you need to connect AX 0c to AXDS2 B-In, AX 0d to AYDS2 B-In, AYe0c to AXDS1 B-In and AY 0d to AYDS1 B-In.

Also I need to mention hardware and software disk ownership. In older system ownership was defined by cable connections. Filer which had connection to shelf A-In port owned all disks in this shelf or stack if there were other shelves daisy chained to channel A. Our FAS3020 for instance already supports software ownership where you can assign any disk to any filer in cluster. It means that it doesn’t matter now which port you use for connection – A-In or B-In. You can reassign disks during configuration.