The storage layer of the traditional computer architecture which we know from the 1960th on has been delevoped over decades. Still it is the slowest layer of the whole hardware architecture pyramide (cpu, level caches, memory, bus types). Therefor it is still the bottleneck in most modern computer systems. In times of virtualization technology the demand on fast storage layers has been increased. In this article I would like to give you some insights into usage of different storage technologies and their impacts.
STORAGE CONSIDERATIONS
The requirements of a storage vary of the purpose the system shall fullfil its task. By answering the following questions you may get a direction of the storage type you require for your individual task:
- Space considerations: How much data volume needs to be handled by the storage?
- Type of data: Which kind of data will be placed on to the storage? (archive data, file sharing, vdisks)
- Frequency: How often will the data be accessed?
- IOPS performance: How many systems will access data simoultaneously?
- Minimum data throughput: Is there any time frame data needs to be processed?
- Availability: In which time frames is an unavailabilty of the data tenable? In which time periods the data needs to be accessible not to generate any business impact?
- Backup: How will the data of the storage be replicated? How often will it be replicated?
BENCHMARK CONSIDERATIONS
When using benchmarking software you should take into account the following rules not to become unhappy at some point:
- When benchmarlking systems always use the same version of the used software to make the results comparable.
- Publish your results in most details: give details about the hardware by stating its manufacturer, model type, size, hard disk rpm, interface, power consumption
STORAGE BENCHMARKING SOFTWARE
You may find a lot of benchmarking software on the market. But there is only a few I can suggest:
- Iometer
- AS SSD
- HDtune
BENCHMARKING RESULTS
Below you will find some benchmarking results I collected during my tests with various system setups. I hope my comments help you for your own considerations.
Iometer
Iometer is one of the most common benchmarking tools to test iops performance. There exist a VMware forum thread having specified four tests for VMware environments, see chapter 'Sources':
NAS Synology RS2414+
The Synology NAS RS2414+ has been installed to carry all first level backup data and working as vdisk cache to keep a maximum of five VMs running in case its operative storage needs to be maintained.
Test #1:
SERVER TYPE: Synology RS2414+
CPU TYPE: 2x Intel Atom D2700
OS VERSION: Synology DSM 6.1.2
STORAGE TYPE: WD RED 3TB, 8x hdd, 5400 rpm, S-ATA 3gbps,
RAID-5
FLASH CACHE TYPE:
Samsung 840 Evo 256 GB, 2x SSD, S-ATA 6gbps, RAID-0, Read Only
INTERFACE TYPE: iSCSI, 2x 1gbps, separate vlan, multipathing, round robin
SECTOR SIZE: 8K, VAAI
LUN SETTING: Advanced LUN, Thin Provisioning
TEST HOST TYPE: Windows 10
DURATION OF EACH TEST: 10 minutes
Test name | Latency | Avg iops | Avg MBps | cpu load |
---|---|---|---|---|
Max Throughput-100%Read | 15.56 | 3835 | 119 | 13% |
RealLife-60%Rand-65%Read | 157.46 | 374 | 2 | 8% |
Max Throughput-50%Read | 17.21 | 3135 | 97 | 5% |
Random-8k-70%Read | 84.22 | 682 | 5 | 8% |
According to the results [...]
Test #2:
SERVER TYPE: Synology RS2414+
CPU TYPE: 2x Intel Atom D2700
OS VERSION: Synology DSM 6.1.2
STORAGE TYPE: WD RED 3TB, 8x hdd, 5400 rpm, S-ATA 3gbps,
RAID-5
FLASH CACHE TYPE:
Samsung 840 Evo 256 GB, 2x SSD, S-ATA 6gbps, RAID-0, Read Only
INTERFACE TYPE: iSCSI, 2x 1gbps, separate vlan, multipathing, round robin
SECTOR SIZE: 8K, VAAI
LUN SETTING: Standard LUN, Eager Provisioning
TEST HOST TYPE: Windows 10
DURATION OF EACH TEST: 10 minutes
Test name | Latency | Avg iops | Avg MBps | cpu load |
---|---|---|---|---|
Max Throughput-100%Read | 15.48 | 3855 | 120 | 6% |
RealLife-60%Rand-65%Read | 135.45 | 434 | 3 | 7% |
Max Throughput-50%Read | 16.48 | 3303 | 103 | 5% |
Random-8k-70%Read | 74.03 | 768 | 6 | 9% |
Intel FC Storage
...
Intel Server X
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Sources
- https://en.wikipedia.org/wiki/Von_Neumann_architecture
- IBM System/360 > Direct access storage devices (DASD)
https://en.wikipedia.org/wiki/IBM_System/360 - VMware Forum thread "Open unofficial storage performance thread"
https://communities.vmware.com/thread/73745 - New !! Open unofficial storage performance thread
https://communities.vmware.com/thread/197844 - http://vmktree.org/iometer/