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Based on the tests run using the ESRP – Storage framework, AMI
recommends the following best practices to improve storage performance:
Consider performance before capacity
:
RAID10 configurations are
recommended for performance and fault-tolerance mirroring
(multiples of 2) RAID 5 configurations with more drives in an array
are to be avoided for key volumes that has small random writes. Log
devices are essentially sequentially written. Write back caching is
very helpful here as it reduces latencies from 20ms to 2ms.
StorTrends iTX with an advanced cache module offers excellent
performance benefits.
Invest in high performance disks and spindles
:
It is imperative to
make sure that volumes are distributed across multiple spindles.
StorTrends iTX software houses RAIDed logical drives in containers
from where capacity is allotted to various volumes. Intelligent
provisioning strategies allow the I/Os to be appropriately striped
across various logical drives to ensure leadership in performance.
I/O alignment
:
In general MS Exchange I/Os are predominantly 4K
in size. It is therefore important to ensure that these logical
transaction I/Os are not split into different spindles. Splitting
increases physical I/Os and therefore degrades performance. By
default Windows aligns the partition to 63
rd
sector. This implies that
one out of every 16 I/OS will be split, causing performance penalty.
It is advisable to use Microsoft tool
diskpart
to align the volumes to
4k alignment.
“diskpart –i 1”
command will ensure this alignment.
Isolate network traffic
:
Let LAN traffic live on LAN and SAN traffic
on SAN network. Isolate the Microsoft Exchange database workload
from other I/O intensive applications or workloads. This ensures the
highest levels of performance for Microsoft Exchange and makes
troubleshooting efforts easier in the event of a disk-related
Microsoft Exchange performance issue.
Multiple Paths
: With multiple NICs, Microsoft MPIO should be
enabled on Exchange servers to ensure highly-available SAN
connections and load-balancing & failover paths.
Network switching
:
For best results, use non-blocking Gigabit
Ethernet switches that support both Jumbo Frames and Flow
Control.
Application Isolation
:
Do not install Exchange server on a Domain
Controller or ADS Server
.
It is best to ensure application isolation
and thereby improving performance.
