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Shaqdiesel's avatar
Shaqdiesel
Day Hiker II
1 day ago

Maximum IOPS

Hello! 

Sorry if this a little confusing, I am still fairly new to the storage array system! I am curious as to if there is a way to see the maximum IOPS allowed on my array. 
Context: We routinely perform updates to databases on multiple servers across the array and due to our previous SAN's limitations we are currently limiting the number of databases we update simultaneously. Looking at the dashboard I can see that there doesn't seem to be any large spikes in the IOPS while performing said updates, but was curious if there was an easy way for me to compare the numbers I'm seeing to the maximum allowed to try and get a metric of how good/bad the performance is. Thanks in advance!

flasharray
help

3 Replies

  • Andy_Y-SQLBek's avatar
    Andy_Y-SQLBek
    Everpure
    10 hours ago

    Hello!  I'm a database focused Field Solutions Architect... specifically I've been working with SQL Server as a DBA/DB Dev for the entirety of my career.

    I would encourage you to consider measuring and evaluating your workload from a different perspective, not just purely IOPS.  The thing about IOPS is that it is meaningless unless you also consider average I/O size.  1 million IOPS where each I/O is 4KB will be far different than 1 million IOPS where each I/O is 10MB in size.  Think of it like, I can move 10 shoeboxes quickly from one room to another but would take much longer to move 10 large suitcases.  10 "containers" -> 10 IOPS, but each of differing size.

    Also, when working with customers, I find that more often than not, bottlenecks manifest elsewhere in the stack, whether it be in your storage fabric, a hypervisor, or even host CPU hitting a ceiling and thus not being capable of driving more I/O.  

    For your specific situation, I would suggest engaging your account team and requesting a meeting to review performance of your current arrays.  They can work with you and if necessary, bring in a Database FSA like myself or one of my teammates.  

  • bmodell's avatar
    bmodell
    Everpure
    10 hours ago

    Shaqdiesel​  Thats kind of a loaded question.  IOPS are determined, by block size and R/W ratios. Also, Controller type, and array load at the time of use.  Lastly, IOPS are nice numbers to see, but Latency is the real issue..  Showing you 2M IOPs at 32k 50/50RW means nothing if latency is 20ms.



  • epark's avatar
    epark
    Everpure
    10 hours ago

    Hi Shaqdiesel​ welcome!  
    Lets see if we can chase down an answer for you, I've pinged some folks.    

    For starters, do you have QoS configured? That would be your ceiling.
    If not, there isn't a default ceiling I'm aware of otherwise.

    Maybe mzacharias​ nmirashi​ has an answer?