59 votes

Why do IOPS matter?

This is because sequential throughput is not how most I/O activity occurs. Random reads/write operations are more representative of normal system activity, and that's usually bound by IOPS. ...
ewwhite's user avatar
  • 198k
38 votes
Accepted

Why do IOPS matter?

Throughput Throughput is useful when you're doing things like copying files. When you're doing almost anything else it's random reads and writes across the disk that will limit you. IOPS IOPS ...
Tim's user avatar
  • 32.7k
14 votes
Accepted

Impact of RAID levels on IOPS

For HDD, IOPS are generally dominated by disk's access time, which is the sum of seek latency + rotational delay + transfer delay. As these variables strongly depend on the access patterns and have ...
shodanshok's user avatar
  • 50.5k
6 votes

Microsoft performance monitor counter - Disk activity & file

You can't do that. There's no way to traverse back IRP owner in Windows storage stack: you have to have a (pretty complex BTW) 3rd party filter driver and associated wrapping. SAN vendors like say ...
BaronSamedi1958's user avatar
6 votes

Why do IOPS matter?

While ewwhite's answer is completely correct, I wanted to provide some more concrete numbers just to help put why the difference matters in perspective. As ewwhite already correctly stated, most non-...
reirab's user avatar
  • 162
6 votes

Is AWS i3.2xlarge limited to 10K IOPS?

Are you 100% sure you're writing to the local SSD storage? It sounds like you may be accidentally using the EBS volume instead, the 10K IOPS limit would suggest that... How to check: In Amazon ...
MLu's user avatar
  • 25.4k
4 votes

How to calculate current IOPS usage and IOPS credit count and graph on AWS RDS

As mentioned in How can I see my IOPS burst credits? (source): Unfortunately there isn't a Cloudwatch Metric for the current IOPS Credit balance like there is with the CPU credits. This has still ...
BenMorel's user avatar
  • 4,607
4 votes

Why do IOPS matter?

To perform an IO operation the drive(s) must go through a series of operations. For a mechanical hard drive they need to. Seek to the right track and select the right head. Wait for the platter to ...
Peter Green's user avatar
  • 4,296
4 votes
Accepted

Get an AWS EC2 ebs volume to perform over 20,000 IOPS

RAID of EBS volumes is certainly possible. Amazon even has documentation on it: http://docs.aws.amazon.com/AWSEC2/latest/WindowsGuide/raid-config.html They're presented to the OS as simple devices, ...
Martijn Heemels's user avatar
4 votes
Accepted

VMWare ESXI extremely high write latency

The latency can be caused by disk provisioning in Virtual Machine. Double check both networking and disk provisioning. I’d recommend Thick provisioned Eager Zeroed type of provisioning to avoid READ->...
batistuta09's user avatar
  • 9,106
3 votes
Accepted

IOPS super low after creating volume from snapshot (AWS)

EBS snapshots are stored in S3. When you create a volume from a snapshot, blocks are first pulled incrementally from S3 to EBS in the FIRST read operation, and from that point all subsequent reads for ...
ma.tome's user avatar
  • 1,179
3 votes
Accepted

Terrible (~1.4x vs expected ~2x) random read performance in new ZFS mirror (raid1)

ZFS uses ARC not just for file caching, but for many performance optimizations, such as prefetch and, probably most importantly, metadata. If you have no cache, ZFS has to read the metadata from the ...
mzhaase's user avatar
  • 3,848
3 votes
Accepted

How should I interpret disk IOPS listed by cloud hosting providers vs. those listed by drive manufacturers?

Google does specify 900.000 to 2.700.000 IOPS for a local SSD. That shows their hardware is perfectly capable. The "zonal SSD" has a much lower IOPS, but that is a disk which is accessible ...
MSalters's user avatar
  • 700
2 votes

How to calculate current IOPS usage and IOPS credit count and graph on AWS RDS

Although burst balance graph is not yet available in web console it can be retrieved in aws cli with command like this: aws cloudwatch get-metric-statistics --namespace AWS/RDS --metric-name ...
Vladimir's user avatar
  • 596
2 votes

How to calculate current IOPS usage and IOPS credit count and graph on AWS RDS

AWS just released the feature, this may help you to monitor your IOPS: Burst Bucket Metric Now Available for Amazon EBS General Purpose SSD (gp2) Volumes (at the moment it's only available for gp2 ...
Sebastien Horin's user avatar
2 votes

Why does storage's performance change at various queue depths?

Old question, but deserves more info due to the number of times it gets seen. This answer is based on SSDs, since that's what the original question is about. Queue depth and the variation of IOPS ...
JLS's user avatar
  • 21
2 votes
Accepted

How to configure Fio to a more accurate result of IOPs

Reading the man page yields runtime=int Terminate processing after the specified number of seconds. time_based If given, run for the specified runtime duration even if ...
Sven's user avatar
  • 99.5k
2 votes

Why do IOPS matter?

Generally speaking, IOPS is more difficult to get than throughput. If you have lots of IOPS, you will have enough throughput most of the time. With classic hard drives, the number of axes is your ...
Xavier Nicollet's user avatar
2 votes

Why do IOPS matter?

There are two types of bottleneck that you can experience on IO volumes (or IO in general in fact). Actual performance is indeed measured to include a component based on the volume of data moved, ...
Iain Price's user avatar
2 votes

Get an AWS EC2 ebs volume to perform over 20,000 IOPS

That such IO rates in a single EBS volume are simply not possible, at least not right now. As mentioned, RAIDs of EBS volumes should fit your needs, both GP2 and PIOPS, but an upper limit per instance ...
ma.tome's user avatar
  • 1,179
2 votes
Accepted

Strange IOPS performance on AWS R3.large & R4.large instances

Your constraint appears to be coming from the network limits on the instance type, not EBS itself. There's some reading between the lines required, but the EBS Optimized Instances documentation ...
Michael - sqlbot's user avatar
2 votes

Why do IOPS matter?

I will be answering my own question as well because I think most answers went a lot off topic and the answer could be a lot simpler: If you look at your storage devices throughput only, you might ...
mFeinstein's user avatar
2 votes

Why do IOPS matter?

Answering your question "What new piece of information do I get when I see an IOPS number, that I wouldn't get seeing a throughput (MB/s) number?" directly, it is how many IO operations of ...
Eugene's user avatar
  • 297
2 votes

Impact of RAID levels on IOPS

It's just a matter of definitions. You can measure IOPS at different levels in the system and you will get different values. For example, suppose you have two mirrored disks and you are writing as ...
David Schwartz's user avatar
2 votes

Is there a better way to handle 100-200+ files/s?

This sounds like an AWS Architect Pro exam question. It seems fairly straightforward to solve the scale and price concerns. There are many options, here's the first one that came to me. If you'd said ...
Tim's user avatar
  • 32.7k
2 votes

Is AWS i3.2xlarge limited to 10K IOPS?

This page on AWS says the i3.2xlarge can do 412,500 random read IOPS and 180,000 write IOPS. In comparison the i3.16Xlarge can do 3.3 million random read IOPS and 1.4 million write IOPS. It also says ...
Tim's user avatar
  • 32.7k
2 votes

Is AWS i3.2xlarge limited to 10K IOPS?

On AWS the IOPS rate is limited per-volume. If you need a higher throughput it's best to use a higher number of smaller volumes rather than one huge volume. You can then put the volumes e.g. to SW-...
Fer Dah's user avatar
  • 224
2 votes

How should I interpret disk IOPS listed by cloud hosting providers vs. those listed by drive manufacturers?

Quotas. Multi-tenancy. Counting host IOPS after redundancy. Scalability limits with their (probably IP based) storage stack. Selling a premium faster SSD disk. Actually being honest and conservative ...
John Mahowald's user avatar
2 votes
Accepted

Google compute - Less vCPUs high IOPS vs More vCPUs low IOPS

Reduced memory reduced your cache hits. Assuming you did not change the database's memory configuration, previously it was OS file system buffers which serviced those reads. Relation of system memory ...
John Mahowald's user avatar
1 vote
Accepted

SSD Raid perfomance

That fio job is allowed to do buffered writes and as such the write data can be buffered in RAM and only sent to disk (via writeback) at a later point. Given this, one explanation could be that ...
Anon's user avatar
  • 1,255

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