PowerFlex 4.X Appliance and Rack Design Flashcards
(86 cards)
What are the main 5 components of PowerFlex?
SDS
SDC
SDT
MDM
FSN
What is the SDS?
software that enables a server in the cluster to contribute local storage devices to a native storage pool
What is the SDC?
block device driver that exposes shared block volumes from the SDS to the operating system - runs on the same server as the application
What is the SDT?
manages host connections and controllers that are connected over NVMe/TCP
What is the MDM?
authority that controls and tracks data storage ownership, mapping, and protection.
What is the FSN?
file service node - software component that allows the PowerFlex cluster to make data available over file based protocols
supports SMB, NFS, FTP
How does the SDS work?
owns the contributing devices and forms a protected mesh from which storage pools are created
How does the SDC work?
an application issues an IO request and the SDC fulfills the request regardless of what SDS the requested blocks physically reside on
How does the SDT work?
sends adminstrative and IO commands forward to the SDS programmatically such that the SDS is oblivious to the source of the IO - makes traffic from an SDT look like it came from an SDC
How does the MDM work?
as volumes are created the MDM provides the information application servers need to connect to the cluster’s virtualized storage
What is a protection domain?
group of nodes/SDSs that provide data isolation, security and performance benefits
What is the rule of protection domains?
a node can only participate in one PD
separate PDs can be created for different node types with unequal performance profiles
What is a fault set?
logical entity that contains a group of SDSs within a PD
What is the benefit of fault sets?
SDSs have a higher chance of failing together
by grouping SDSs into a fault set PFlex mirrors the data for a fault set on separate SDSs that are outside of fault set
availability is thus assured even if all the servers within one fault set fail simultaneously
What are the main jobs of fault sets?
used to protect against a failure
performing maintenance tasks when all data in one fault set is mirrored onto a different fault set
What are storage pools?
subset of physical storage devices within a PD - each storage device belongs to a PD
What is the recommendation when it comes to storage pools?
recommend having the same type of storage devices within a pool to ensure that the volumes are distributed across the same type of storage within a PD
What do storage pools define on PowerFlex?
the performance of its volumes based on the type and capacity of drives in the SP
What is mesh communication in PowerFlex?
when the SDC communicates with each SDS simultaneously to maximize throughput
What are the QoS functions on PowerFlex?
limits bandwidth and IOPS for non-critical applications
What does the MDM do when it comes to data layout?
applies granularity rules and protection domain rules to evenly distribute blocks of data across every node
What are the two different granularity rules on PowerFlex?
fine granularity - 4KB block size geared toward compression and snapshots
medium granularity - 1MB block size that are geared toward speed and performance
What are the two different maintenance modes on PowerFlex?
IMM (instant maintenance mode) - minutes long (perfect for rolling upgrades and reboots)
PMM (protected maintenance mode) - available for maintenance windows longer for 30 minutes
What is CloudLink on PowerFlex?
optional application that manages the encryption and providing key management