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Do people still use RAID cards? Whats the best atm

Discussion in 'Storage & Backup' started by dmr, Sep 12, 2017.

  1. fad

    fad Member

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    Windows seems limited in features and performance unless you scale. I am talking 2+ servers and 12-24 disks. I have yet to look at the W2016 features but in W2012R2 the only RAID levels with performance were mirroring. Also to get performant arrays required SSDs in the same quantity as the drive stripe size. I know some of the constraints around SSDs and stripe sizes have been reduced in W2016. Also, the requirement of HA attached SAS drives for dual heads has been removed. Which moves it to better align with Software Define Storage, rather than traditional SAN storage.

    I have been using Ubuntu 16.04.3 with ZFS and have found it to have really good performance and fewer constraints. I have moved a whole bunch of machines to this config.

    That being said I run Windows Storage Spaces, ZFS, and hardware raid at home. They all have their place.
     
  2. fredhoon

    fredhoon Member

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    What are you using HW RAID for at present, how does the write speed compare with a similar RaidZ config in your experience?
     
  3. fad

    fad Member

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    It depends on the config of all of the parameters, and size.

    HW RAID is very limited to the unit you have. The card bandwidth and speed, both internal to the SAS ports and to the PCI-e. It has limited capability to detect errors, and are error-prone unless you are running supported configs and firmware. They, however, are easier to configure and use.

    I have a Dell PowerEdge R720 with 16x1Tb SAS drives on an H710p PERC RAID card, and 24x1Tb SAS on a dual port external card. I also have an ARC-1203-8I areca 8 port card with a few WDC Reds.

    The speeds on the Dell are around 1200MiB/sec, QD=32 small IO, are not that good, around 30-50MiB/sec. Write speed for large blocks was around 800MiB/sec.

    I have run ZFS on a Dell R720xd, 24x1Tb SAS, 4x256Gb SSD with a LSI 9211, with dual ports. The speed was very good, I think the numbers were around the same or higher for 64k block IO. Where ZFS was really good was small random IO, with memory and SSD caching the random IO performance was in the 120k IOPS.

    Hardware RAID has a penalty for the XOR calc, which modern CPUs can do much faster. Most CPUs can do in the 2+GiB/sec. I have not used SSD caching with any modern RAID card.
     
  4. frenchfries

    frenchfries Member

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    Apr 5, 2013
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    Interestingly, you could use your mobo's raid if you use an intel chipset. Aside from the fact that it's portable across intel chipsets as long as they support the same volume types eg raid 5 requires a z platform rather than B etc.

    You can also access these arrays on non intel and intel machines alike with mdadm. Mdadm supports the intel standards (read: metadata) so you just boot your machine and assemble the array.

    I would avoid Dmraid but intel themselves suggest and support mdadm.

    https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/rst-linux-paper.pdf

    Cool shit. This way you can use the simple on board raid for windows and then if it all hits the fan and you move to an amd system you can at least get all of your data from a simple linux bootable usb stick.
     
  5. fad

    fad Member

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    I just bought a Adaptec 71605 card. The firmware was interesting compared to the original Adaptec cards. It seems to be working well, with 8x6Tb drives. Speed is good at around 300-500mb/sec.
     

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