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Azure Premium Disk - to use striping or not? RRS feed

  • Question

  • Hi all,

    I need to store 4x1800GB databases, attached to a DS14_v2 VM.

    I am using Azure Premium disk (4 x P50)

    My question is simply this:-

    Should I stripe all 4 disks to create ~16TB of space and then partition into 4 logical partitions?

    OR

    Should I keep each P50 separate?  (4 drives attached to the VM)

    Pros and Cons of each option?   

    I know striping gives better performance but the IOPS profile of a single disk is way more than we need so that's not a priority.    I also know that MS have 2 or 3 copies of each SSD "for a 0% annualised failure rate" so hopefully RAID 1/5/10 etc. is not required (and not even possible I think on Azure??)


    James M


    • Edited by spooks50 Thursday, November 9, 2017 9:11 AM
    Thursday, November 9, 2017 9:11 AM

All replies

  • If you want to increase the capacity and performance of the volume, you could stripe across your disks. When a high scale VM is attached with several premium storage persistent disks, the disks can be striped together to aggregate their IOPs, bandwidth, and storage capacity.

    Reference: Azure Premium Disk Striping.

    For information on Azure premium storage performance refer the below link and let us know if you need any further assistance:

    Azure Premium Storage: Design for High Performance

    Do click on "Mark as Answer" on the post that helps you, this can be beneficial to other community members.

    Thursday, November 9, 2017 2:34 PM
  • I'm not sure if that was a 'bot' answering?   I KNOW you can increase performance and capacity by striping (I said as much in my post) , you actually didn't answer my question!!

    James M

    Monday, November 13, 2017 8:58 PM
  • It depends, here are a few considerations:

    Striping and then partitioning across the stripe provides a pool of resources to be shared by the databases.  This has advantages and disadvantages.  The advantage is the flexibility that the number of partitions doesn’t have to match the number or size of disks, and that the databases can burst to use more throughput than they would get from a single disk.  You could have 1 5 TB partition, 1 3 TB partition, and 8 1 TB partitions; and any one of them could burst up to the full limit of all the partitions (or the machine limit, whichever they hit first – in this case, probably the machine).  To do the same with physical disks would require a mish mash of different disk sizes and some striping to get the 5 TB partition.

    The disadvantage is that the databases are more likely to interfere with each other (they all share the machine limits, but they can’t exceed their disk limits) and that it’s harder to do things like move a database to another machine (if the database was sitting on a single disk, the disk could be dismounted from one system and mounted on another, that can’t be done with a partition on a stripe set). 

    Azure disks can be striped in any RAID pattern you want: 0, 1, 5, or 10; however, given the triple redundancy at the disk level, we generally just recommend RAID 0 (which is roughly equivalent to RAID 01 or RAID 10).  If that’s insufficient redundancy, then it’s probably time to look at ways to replicate the entire VM to eliminate single points of failure there as well.

     

    Do click on "Mark as Answer" on the post that helps you, this can be beneficial to other community members.

    • Proposed as answer by vikranth s Thursday, November 16, 2017 3:48 PM
    Wednesday, November 15, 2017 4:44 PM
  • Sorry to revive a dead post. What is being very indirectly said is "stripe them to help alleviate Azures complex back end disk throttling" :) 
    Wednesday, January 30, 2019 2:54 AM
  • I set up an azure server with two stripped 4tb standard hdd's.   With non premium, non-managed disks you only get charged for the actually data stored on the disk, not the full drive size.   I had about 1.5 gb of data on that drive.   My charges the first 3 months was about $26.00 each month.   Then something happened, the bill for disk usage skyrocketed.   I looked at the drives in disk management and the stripped drives were "resynching".  I don't know what caused this, but the process sent the storage bill off the charts.   I moved the small amount of data i had on that drive to the c drive and removed those drives.

    So, if you strip on azure, beware of off the chart charges with it.  If using managed disks then you already have off the chart charges and probably won't notice this issue.


    • Edited by coqui123 Saturday, March 14, 2020 11:35 AM
    Saturday, March 14, 2020 11:35 AM