Speed ​​is everything! SSD only! Experience mClouds.ru

We are sharing our experience in building a cloud infrastructure provider mClouds.ru. So, we have already described the experience of choosing a certified TIER3 data center in Moscow, our 10/40 GBE Huawei switches , and have already released the first part of the article on the Cisco Cisco CSR virtual router for VMware cloud environments, but today we will look at the types of disks used by various VPS and IAAS providers and our opinion on their types and applicability in the modern cloud.

On the history and trends.
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We will not go into a long review of the history. Let us only briefly mention that starting from approximately 2012, corporate data centers began to settle storage systems with SSD drives on board. And we, for our experience, did not meet customers who, having tried the performance of their applications on SSD drives, would have returned them to SAS 10-15k only if they pressed the budget. After all, the performance of using SSDs increased by orders of magnitude, removing the headache and causing approving reviews of the business, which somehow began to feel that the money for IT was not just done somewhere, and nothing had changed, but finally - they noticed an increase comfort when working with applications of various ERP and other 1C. And since 2016, the trend for equipping with All-Flash systems has been the most tightly outlined. We, in turn, predict a complete withdrawal from the drive market on spindles for production environments where IOPS are critical. All-Flash systems will fully occupy this market. The performance issue will be removed, only the capacity issue will remain, and here we are waiting for progress on SSD drives. We observe such trends in the storage market for data centers, if very shortly.

Now about the clouds.

Cloud providers, as a rule, use the same industrial servers and storage systems as business users in their corporate data centers. Equipment may differ only in nuances, models, extensibility, but the basic characteristics are the same. They also consider budgets and use different types of disks, ranging from 7.2k SATA to fast SSDs of various types. Someone uses SSD as a cache, and then puts the data on 7.2k. Who else somehow manages to optimize and find compromises. But, as a rule, the customer of the cloud today will face almost 90% of the situation when the IAAS provider forces him to choose where to place his server, on SSD, SAS 10-15k or slow 7.2k drives.

What do we think about this?

When designing our infrastructure, we put ourselves in the place of the customer, and also looked at the time - it was January 2016 outside. What do we see from the customer? We interviewed potential customers on VPS servers. For the most part, the conclusion of the survey was simple - customers do not even want to spend time in the cloud choosing disk types, as if from one to the other, then move on if there isn’t enough performance. They want a fast array for their servers. And they want this array on SSD drives - in the absolute majority of cases it gives noticeably greater performance.



From the side of 2016 - we were sure of two things. SAS disks on spindles - the remaining life is 2-3 years, then everything will die off as SCSI, they are expensive, they give speed to themselves. Building a disk subsystem on SAS is short-sighted and losing in advance in the long term. Cons - to distribute at least 10,000 IOPS, you need to put a couple of shelves with 25 SAS 10k disks. This is not very energy efficient, and not very fast, and will eventually take up a lot of rack space. All these heaps of shelves you've probably already seen on numerous brutal photos from data centers. All this will soon go down in history. Those who notice this are moving to flash disks at a high enough rate. This question is literally a couple of years. Hardly longer. That's what we think about this.

Few conclusions

Summing up our brief overview and answering the question in the title ... We believe that cloud servers, whether they are single pools of VPS servers, or a full set of resources based on the IAAS model, should be only on SSD storages in 2017, ensuring stable application response speed , and not to force the customer to make a choice on the losing side beforehand, immersing him in thoughts, what to place on medium disks, what is slow and what is fast. All business applications should be on fast storage, without compromise. The exception we allow only for archival data.

This is our experience, our vision of the present and near future. Therefore, in our IAAS project mClouds.ru we use only SSD disks. We will talk about the type of our storage in the following series. Stay with us :)