Low RPM Disks to be used as Disk Library

Last post 09-09-2019, 4:44 AM by Wwong. 7 replies.
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  • Low RPM Disks to be used as Disk Library
    Posted: 08-28-2019, 3:55 AM

    Hi Guys,


    I very new to CommVault and I would like to know a few things. Here is our scenario:

    We have (1) Media Agent running as a VM on Nutanix Hypervisor. The majority of our servers are mixed VMs on AHV (Windows VMs) and VMware (Linux VMs). The MA and the VAProxy resides on the AHV

    The current Disk Library is inside Nutanix mounted as DAS on the MA.

    We are thinking of configuring a Physical Server (Re-purpose a HP DL380 G9) that would be as a the new Media Agent. buying hard drives but considering a more cost effective approach.

    Having to plan a new MA as Physical server and possibly configuring Physical hard drives attached to it as the new Disk Library. We are planning to use

    1. 10K Raid 1 for the OS | 300GB Disks 
    2. 400GB SSD  Raid 1 for the DDB | Same size as the current but not SSD nor 15K | is this oK enought?
    3. Raid 5 parity + 1 spare

    > Can we use  Lower RPM Disk Drives for the Disk Library? 10K or 7.2K (Prices on SSDs are very high)

    and is there a documentation on how to make these transision as the Disk Lib is on a Virtual Server and now being moved to Physical?

    The current MA has just one drive for the Disk Library and is at approx 24TB

    Sorry for too much information but any ideas would point to a more solid planning and implementation.


    Thanks a lot.




  • Re: Low RPM Disks to be used as Disk Library
    Posted: 08-28-2019, 5:18 AM


    As far as the storage side of the media agent, there are four components that you need to consider.

    O/S, DDB, Disk Library, and Index Cache - and the size of these four depend on the size of the environment you have.  You haven't mentioned where you would allocate the Index Cache or the size of your environment.

    If you have an "Extra Small" environment (<25TB FET - http://documentation.commvault.com/hds/v11/article?p=1647.htm) you will still need to make some copromise.  I would create a 200GB O/S partition and a 200GB DDB partition off the 400GB SSD, then use the 10k disks for the Index Cache.  For an extra small MediaAgent you need 400GB and 200+ IOPS.  Converting these disks into RAID-0 will give you the capacity, but you won't get 200+ IOPS.

    7.2k Disks are fine, it's more about throughput (so the more spindles the better). Commvault want your disk libraries to be able to read/write at 600GB/Hr or more.

    Hope that helps

  • Re: Low RPM Disks to be used as Disk Library
    Posted: 09-01-2019, 4:14 AM
    Sorry for the late response. Greatly appreciate all the efforts!

    We are falling under the category of Small and our MA is configured near that spec sheet.

    I missed that Index Cache but I would like to allocate the SSD for it as well.

    Can we use the 10K hard drives for OS only (We already have this and the rest we are planning to buy) or would it affect the OS that we really need to be @ 15K for the OS?

    Can we use the SSD for the Index Cache (300GB) and DDB(400GB)

    Doing some searching for our servers compatible parts I saw some Read Intensive; Write Intensive and also a Mixed Use SSDs(MU are too expensive though). for the Index and DDB which would be preferred?

    Write Intensive SSD HPE 400GB SAS 12G WI SFF (2.5 in) SC 3 yr warranty DS firmwareSSD
    Read Itensive SSD HPE 480GB SAS 12G RI SFF (2.5 in) SC 3 yr warranty DS firmwareSSD

    For the Disk Library
    10K Drives | we can only use SFF so the largest size we can put in there is up to 2.4TB

    Is there a link where I can try to see the projected IOPs for disk we are planning to use?

  • Re: Low RPM Disks to be used as Disk Library
    Posted: 09-03-2019, 7:48 AM

    Hi cvronimus

    Base on your requirement and the additional details provided by Anthony, here are some additional notes:

    • It should be fine to have the OS installed on the 10K disk (assuming that you will also have the Commvault Binary installed in the same location)
    • The use of SSD for DDB is definitely a good option ensurion optimal performance during Deduplicated Backup 
    • For Index Cache the usual recommendation is to have minimum 400 GB (as index requirement can be quite high due - depending on the amount of Objects that you are protecting)
    • For SSD I would recommend a balance of Write intensive for the DDB as you will be inserting/updating references regularly
    • The use of 10 K disk is also fine for the Disk Storage (and as recommended by Anthony, best to have multiple Spindle, as you will achieve higher IOPs when data is stiped across multiple spindles)
    Finally if you are looking for a method to test IOPs (for SSD or Mounth Path) you can consider using IOMeter (tool provided by Intel) which is installed in the Base Folder of Mediaagent (https://documentation.commvault.com/commvault/v11/article?p=8825.htm)
    Hopefully this helps 
  • Re: Low RPM Disks to be used as Disk Library
    Posted: 09-08-2019, 9:19 AM

    Hi Winston,



    This will help us a lot. I will use these as references.


    Thank you so much!



  • Re: Low RPM Disks to be used as Disk Library
    Posted: 09-08-2019, 9:57 AM
    You should find that 7.2k RPM disks are fine for a disk library. Just so long as you don't go for a small number of ultra high density disks.
  • Re: Low RPM Disks to be used as Disk Library
    Posted: 09-08-2019, 10:01 AM

    Thank you for your inputs as well

    Greatly appreciate it!

  • Re: Low RPM Disks to be used as Disk Library
    Posted: 09-09-2019, 4:44 AM

    Hi cvronimus

    No problem, feel free to reach out if you like to bounce off other questions 



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