Midrange Storage Performance Planning: Drive Configuration Flashcards
What is the makeup of a Unity XT DPE?
houses 25 drive slots
populated in system from left to right
How does the Unity recognize the DPE?
Bus 99 Enclosure 0
internal drives are recognized as Bus 99 Enclosure 0 Drive - Bus 0 Enclosure 0 Drive 24
LEDs on front of DPE for enclosure and drives to indicate status and faults
What is the DPE for Unity XT 380?
houses 25 drive slots supporting 2.5in SAS and SAS Flash drives
first 4 slots reserved for system drives
What are the role of the 4 system drives on the Unity XT DPE?
contain data used by operating environment (OE) software - configuration and other critical data
space reserved for system and remaining space available for storage pools
Can you remove the system drives in a Unity XT DPE?
drives should not be moved within the DPE or relocated to another enclosure
What is the capacity difference on system drives for Unity XT DPE?
about 107GB less than the other drives due to system partitions
How would you offset the capacity difference from system drives to non-system drives in Unity XT storage pools?
use smaller RAID width for pools that contain system drives
Can system drives be used in a normal storage pool?
Yes just offer less usable capacity
What are considerations when utilizing system drives in a storage pool in Unity XT?
count towards how many reserved hot spares to use
unbound system drives can’t be used as hot spares
Why can’t unbound system drives be used as hot spares?
due to capacity difference system won’t add them to storage pools if not already bounded
only after all other spares have been used will they be added
What is the recommendation when building smaller configurations in relation to system drives?
using system drives in storage pools are encouraged to maximize capacity/performance
What is the recommendation when building larger configurations in relation to system drives?
do not use system drives in storage pools
heavy client workloads to these drives might interfere with system ability to capture configuration changes and result in slow management operations
What are the rules for system drives and storage pools for Unity XT AFA?
no restrictions on using system drives in AFA systems
What are the available drive types on Unity XT?
SAS 10K
NL-SAS 7.2K
SAS Flash 2
SAS Flash 3
SAS Flash 4
What are the characteristics of the SAS 10K drives in Unity XT?
4K block size (2.5 in)
600GB, 1.2TB, 1.8TB
can be used in 25 drive DAE or 80 drive DAE
What are the characteristics of the NL-SAS 7.2K drives in Unity XT?
4K block size (3.5in)
4TB, 6TB, 12TB
12GB/s backend interface
What are the characteristics of the SAS Flash 2 drives in Unity XT?
only supports 400GB size
520 byte block size
supported in FAST Cache, Mixed, or AF Pools
What are the characteristics of the SAS Flash 3 drives in Unity XT?
800GB, 1.6TB, 3.2TB
520 byte block size
supported in Mixed & AF pools
can’t be used in FAST Cache
What are the characteristics of the SAS Flash 4 drives in Unity XT?
1.92TB, 3.84TB, 7.68TB, 15.36TB
520 byte block size
can be used w/ any other SAS flash drives in a pool
can only be used in AF pools
can be used in system drive slots
What is the limitation on SAS Flash 4 on Unity HFA systems?
can only use 7.68TB size
What is SSD wear leveling?
flash cells wear out as data is written to the drive
SSDs have limits for the amount of program/erase cycles (PE) before devices becomes unreliable
What are the classifications for drives when it comes to wear leveling?
High Endurance (HE)
Medium Endurance (ME)
Low Endurance (LE)
What does Unity XT do to minimize wear leveling?
wear leveling optimization
ensures flash drives don’t prematurely wear out
What does wear level optimization do in Unity XT?
limit the number of writes to the drive
drive given certain quota of writes calculated based on wearing consumption model
What takes into account wear level?
slice allocation requests
system determines which RAID group that the slice is allocated in an attempt to balance wear across RAID groups
What can a customer view in Unisphere for wear leveling on flash drives in Unity XT?
can view wear alerts
Proactive copy operations (PACO)
drive health status updates
What drives can be used in mixed pools in Unity XT?
NL-SAS
SAS
SAS Flash 2
SAS Flash 3
What drives can be used in AF pools in Unity XT?
SAS Flash 3
SAS Flash 4
What is the drive sparing rule in Unity XT?
same drive type must be used for spares
EX: SAS Flash 4 requires SAS Flash 4 for sparing
What are the two types of DAEs?
2U 25 drive 2.5 inch drives
3U 15 drive 3.5 inch drives
each model supports different number of drive slots
What are the maximum drive slots for each model?
380 - 500
480 - 750
680 - 1000
880 - 1500
What if the drives in the storage pool are near maximum IOPS in a Unity XT?
if near maximum IOPS for extended period add more drives to pool
spreads load across more resources
What are the maximum IOPS per drive type for Unity XT?
SAS Flash - 20000
SAS 15K - 350
SAS 10K - 250
NL-SAS - 150
What setup doesn’t require hot spares in Unity XT?
dynamic pools
How are traditional storage pools setup with hot spares in Unity XT?
automatically reserve one unbound drive out of every 31 drives of a given type as a hot spare
hot spares have no special configuration
Can traditional pools be expanded or created in Unity XT?
only if available number of unbound drives is sufficient to create the requested pool and continue to satisfy the hot spare policy
How would you change the number of hot spares in a Unity XT?
decreasing number of individual drive types in system
Why do Unity XT systems throttle hot spare rebuild operations?
to reduce the impact to host IO
rebuilds occur more quickly during periods of low utilization
What is included in the base chassis of Powerstore?
two nodes
midplane
NVMe devices
What is included in the nodes of Powerstore?
CPU
DRAM
IO Modules w/ ports
power supply
fans
What is the role of nodes in Powerstore?
perform tasks of saving and retrieving block, file and VM data
How many drives slots are in the Powerstore base enclosure?
25 NVMe - 2.5in
What are the first 20 drives in a Powerstore base enclosure?
NVMe SSD or SCM
What are drives 21-24 in a Powerstore base enclosure?
NVMe NVRAM SSDs (except Powerstore 500T)
What are the LEDs on Powerstore drives?
Ready/Activity = Blue
Fault = Red
What is the WWN Seed tag on Powerstore?
blue pull out tag located between slots 7 and 8
What is the Dell Serial Number Tag on Powerstore?
black pull out tag between slots 16 and 17
What is the base enclosure makeup of Powerstore 500T?
slots 0-24 are used for data storage - no NVRAM drives
write caching and vaulting performed by internal M.2 module
What is the base enclosure makeup of Powerstore 1000T-3200T?
last two slots (23/24) populated with NVMe NVRAM drives (write caching and vaulting)
slots 21 and 22 must remain unpopulated
What is the base enclosure makeup of Powerstore 5000T-9200T?
populated w/ 4 NVMe NVRAM drives (21-24) (write caching and vaulting)
What are the drive rules for Powerstore?
4 capacities of NVMe Flash in base and expansion enclosure
1 capacity of NVRAM drives in base enclosure
systems with only NVMe SCM do not support expansion enclosures
all drives 100% FIPS certified
What are the caviats for Powerstore using SCM drives?
systems with only NVMe SCM do not support expansion enclosures
mixed SSD/SCM enclosures - SCM drives used for metadata tiering (done automatically by the system)
SCM drives do not add to capacity for user data
What are the expansion enclosure options for Powerstore?
ENS24 - NVMe
ESS25 - SAS
What are the characteristics of the ENS24 expansion enclosure?
uses NVMe-oF standards - delivers end to end NVMe solutions
slots for 24 drives
performance equal to local PCIe NVMe drives - 10 microsecond delay
don’t work with systems already using SAS expansion enclosures
does not support NVMe SCM
What are the characteristics of the ESS25 expansion enclosure?
slots for 25 drives
12 Gb/s SAS interface using two LCCs - A and B for communication between nodes and expansion enclosures
not supported on systems that are using NVMe expansion enclosures
What are the processor configurations for Powerstore models?
500 - 2 Intel Xeon 24 cores 2.2GHz
1200 - 4 Intel Xeon 40 cores 2.4 GHz
3200 -4 Intel Xeon 64 cores 2.1 GHz
5200 - 4 Intel Xeon 96 cores 2.2GHz
9200 - 4 Intel Xeon 112 cores 2.2 GHz
What are the memory configurations for Powerstore models?
500 - 192GB
1200 - 384GB
3200 - 768GB
5200 - 1152GB
9200 - 2560GB
What are the max drive configurations for Powerstore models?
500 - 97
1200 + - 93
What are the NVRAM drive configurations for Powerstore models?
500 - N/A
1200 - 2
3200 - 2
5200 - 4
9200 - 4
What is the minimum drive count for a Powerstore configuration?
6 drives
