Midrange Storage Performance Planning: Back-end Connectivity Flashcards
What are the back-end SAS ports used for on Unity XT?
SPs use them to move data to and from the back-end drives
How are SAS ports configured on Unity XT?
2 onboard 12Gb SAS ports for each SP within the DPE
What are the maximum IOPS per port?
250,000 IOPS
What is the maximum bandwidth per port?
2500 MB/s
How do DAEs get connected?
two buses connected to mini-SAS HD ports
How is SAS Port 0 connected?
internally to the SAS expander
expander connects to front facing drives
connection labeled BE0 EA0
What is special about Unity 480 XT and higher SAS buses?
one internal SAS bus dedicated to the DPE
DPE drives directly accessed by the underlying SAS controllers over internal connections
DPE operates on bus 99 - separate from SAS expansion ports
read/write bandwidth higher than Unity XT 380 w/ no expansion
What are the guidelines to follow on DAEs for Unity XT?
maximum number of enclosures per bus is 10
maximum number of drive slots per bus is 250
evenly distribute DAEs across back end buses
What may be required to achieve maximum drive counts of Unity systems?
extra 12Gb SAS backend IO modules
When can DAEs be added to a Unity XT?
while the OS is active up to the DAE and drive slot limit
DAEs/drive slots over the system limit are not allowed to come online
What drives have the highest performance potential for Unity XT?
SAS Flash
What is true about DAEs?
do not add performance by themselves - allow addition of more drive which can improve performance
What is the SAS IO Module on Unity 480 XT or higher?
4 port 12Gb optional module for extra back-end buses
mirrored IO modules provide 8 x 4 lane or 4 x 8 lane 12Gb/s SAS ports per array for BE connection
When is the SAS IO Module required for Unity 480 XT or higher?
system requires high bandwidth (greater than 10Gb/s)
system is attaching more than 19 DAEs
system contains more than 500 drives
What’s an important con about having to add the SAS IO module to a Unity 480 XT or higher?
consumes an expansion slot that could otherwise be used for front end connectivity
How is the back end cabling connected in Unity XT DAEs?
first DAE is cabled to DPE SAS Port 1 to begin back-end bus 1 as enclosure 0 (BE1 EA0)
rest of DAEs in bus are daisy chained where they are intertwined
What is the embedded IO module on Powerstore 1000T-9000T?
embedded IO module v1 on each of the nodes
has 2 onboard 12 Gb SAS ports for attaching SAS Expansion Enclosures
base enclosure supports 2 redundant connections to expansion enclosure (Link Control Card A and B)
What does the embedded module on Powerstore 1000T-9000T not support?
2 port card (100GbE QSFP)
no NVMe expansion
What is required for NVMe expansion shelves on Powerstore?
module must be converted to embedded IO Module v2
What are the cabling recommendations for connecting expansion enclosures for Powerstore?
use 2 meter cable to connect base to expansion
use 1 meter cable to connect expansions to each other
What is true about back end cabling in Powerstore?
back-end SAS cabling is same regardless of model
How would you connect a single expansion shelf in Powerstore?
cable both IO modules on the base enclosure to the LCC on the first expansion enclosure
What is the back end NVMe cabling for Powerstore 500T?
the 4 Port Mezz card in each node provides two NVMe ports
ports 2 and 3 used for back end connectivity to ENS24 expansion
each base enclosure supports two redundant connections to expansion enclosure
How would you connect two expansion shelves in Powerstore?
cable both IO modules on the base enclosure to the LCC on the first expansion enclosure
cable both IO modules on the base enclosure to the LCCs on the last expansion in the stack
cable expansion enclosure to expansion enclosure
