FlashArray Flashcards
(33 cards)
How many drives can fail on one RAID HA group?
2
What is the minimum number of drives a FlashArray can run on?
5
How many 9s of availability on a FlashArray?
6 9s
99.9999%
How do you power off a FlashArray?
Pull the power cables
What is the minimum version of Purity//FA required for SafeMode?
FlashArray SafeMode requires Purity//FA 5.3.7 or later
What is the minimum version of Purity//FA required for ActiveCluster IP?
For new IP replication installs, Purity//FA 5.2.4 or greater must be installed
What is the minimum version of Purity//FA required for ActiveCluster FC?
For new Fibre Channel replication installs, Purity//FA 6.1.x or greater must be installed
What is the minimum version of Purity//FA required for ActiveDR?
For new installs, Purity//FA 6.0.1 or greater must be installed.
What is VM Analytics?
VM Analytics offers a visual representation of the IO path from the VM all the way through to the FlashArray
How long should data have been moved to the array before data reduction is likely to have reached expected levels?
~1 day for every 2TB of data migrated on to the array
Usable capacity in TiB is typically what percentage of raw capacity in TB?
Between 60% - 70%
At which version of Purity//FA did SafeMode support automatic snapshots and provide GUI based SafeMode status?
Purity//FA 6.2.x
What are the benefits of the Front-End Active/Active architecture?
No need for advanced multi-pathing software
All devices are balanced across all ports - no ownership
No device to initiator mapping
What are the benefits of the Back-End Active/Standby architecture?
No performance impact during controller failure
No tuning or balancing required to avoid over 100% in failure mode
What is the customer value of our Front-End Active/Active and Back-End Active/Standby architecture?
The consumer only focuses on balancing the SAN, we do the rest
Enable technology transition to next generation without impact
NDU
What does ARP stand for?
Acknowledge
Reduce
Protect
What are the 15 architectural decisions which guide FlashArray development?
1) Built in Simplicity
2) Most Efficient Architecture at Scale
3) Consumer Flash (MLC)
4) Data Reduction
5) Stateless Controllers
6) Front End Active/Active and Back End Active/Standby
7) Streamlined Code Paths
8) Immutable, Usable Snapshots
9) Realistic Efficiency Metrics
10) Adaptive Flexible RAID
11) Security and Encryption: All the Data, All the Time
12) Metadata: The Secret Sauce
13) Proactive, Predictive Support
14) Non-Disruptive Everything
What are the three key process of the Acknowledge stage?
Checksum
Copy to NVRAM
Acknowledge to host
What are the three key process of the Reduce stage?
Pattern removal
Deduplication
Compression
What are the three key process of the Protect stage?
Create RAID-HA segments
Flush writes via flash scheduler
Encrypt
What are the key processes of FlashCare
Global wear levelling and refresh
Global deletion management
Integrity checking
Continuous optimisation
What are the processes in the Read of an IO?
Multi-path Read
- Read from fastest path via scheduler
- Decompress
Validate and Serve
- Validate checksums
Describe the process of a write request
1) WRITE_RQST to Block Driver
2) Prepare I/O Buffer (DRAM)
3) XFER_RDY
4) Data comes in via either controller
5) Mirrored to I/O Buffer in each controller
6) Primary I/O buffer duplicates block to at least two NVRAM cards
7) ACK to host, data is secured even in event of power loss
Describe the in-line Data Reduction Steps
1) Identify and remove Zeros
2) Identify and remove Patterns
3) Identify and remove Duplicate Blocks
4) Compress Unique Blocks
