March 2013
Dell EqualLogic Configuration Guide v14.1
9-86
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Not all M-Series I/O modules can be stacked together or with external switches. Typically,
each M-Series I/O modules model can only stack with modules of the same exact model. It
may also be possible to stack M-Series I/O modules with some “stack compatible” stand-alone
PowerConnect switch models. The table below provides stack compatibility information.
Table 31
Stack Compatibility for M-Series I/O modules
Stack Compatible Switches
Maximum
Stack Size
Recommended
Stack Size
PowerConnect M6220
PowerConnect M6220
PowerConnect 6224
PowerConnect 6248
10
4
PowerConnect M6348
PowerConnect M6348
PowerConnect 7024
PowerConnect 7048
12
6
PowerConnect M8428-k
N/A
N/A
N/A
PowerConnect M8024-k
M8024-k
6
6
Force10 MXL
Force10 MXL
6
4
Cisco Catalyst Blade Switch 3032
N/A
N/A
N/A
Cisco Catalyst Blade Switch 3130G
Catalyst BS3130G
Catalyst BS3130X
8
4
Cisco Catalyst Blade Switch 3130X
Catalyst BS3130G
Catalyst BS3130X
8
4
SAN Design for a Single M1000e Enclosure
For a single M1000e enclosure, there is a requirement to use two blade I/O modules for redundancy.
Depending on the blade I/O module model, you may use either stacking or link aggregation as
described earlier in Table 30. Where stacking is supported, this will most likely be the primary method
of interconnecting the blade I/O modules to create a single switch fabric. SAN switches can be
located in any of the three enclosure fabrics and it is not required that the blade I/O modules be in the
same enclosure fabric, though it is typical that the two I/O modules would be in the same enclosure
fabric.
Placing the blade I/O modules in the same fabric does remove one aspect of high availability in that
each blade server will have both of the SAN ports located on the same fabric mezzanine card. This
creates a potential single point of failure if the mezzanine card as a whole fails.
One alternative configuration would be to place the two blade I/O modules into enclosure slots
associated with two different enclosure fabrics (B1 and C1 for example). This has the advantage that
each blade server will have its Ethernet ports connected to these blade I/O modules on two different
mezzanine cards. This ensures that even if a single mezzanine card fails, there is still an active port on
the SAN network.
Table 32 and Table 33 illustrate the stacking strategies between the two I/O modules in each of these
two configurations as described.
