ZFS on Linux - arc not used

Discussion in 'Solaris, Nexenta, OpenIndiana, and napp-it' started by Stril, Jan 29, 2019.

  1. Stril

    Stril Member

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    Hi!

    I will test Solaris, but I think, there most be an issue with the hardware, as Freenas is showing such a different performance in the two systems...

    19s vs over 3 minutes.

    I hope, it's only one bad disk...
     
    #21
  2. zxv

    zxv The more I C, the less I see.

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    Here is another option to narrow down the cause.
    This might help identify whether it's local filesystem issue vs a transport/Samba integration issue.

    On the file server local host, in the root of the ZFS, and EXT4 filesystems, run:

    time find . -ctime 1 >/dev/null

    That makes a stat() call on each and every file and directory.
    Run it more than once and take the time of the last run.
    That should reproduce in part the effect of robocopy, but without Samba.
    If this also shows similar differences between filesystems, it may point to the filesystem itself and not a Samba tuning issue.
     
    #22
    fossxplorer likes this.
  3. Stril

    Stril Member

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    Hi!

    It must be something completely different:

    FreeNAS -Tests:


    1. 32xSAS-Pool, 2x CPU E5-2643 v2, 128 GB RAM
    2:24 min
    2. NVMe-Pool (Intel 900P), 2x CPU E5-2643 v2, 128 GB RAM
    2:23 min

    3. VM on VMWare ESXi 6.7, 32GB RAM, CPU Intel Gold 6124, 4 Cores, iSCSI-storage as VHD
    0:19 min


    I am on a trip for the next 4 days and hope to get any idea on what the problem is and test Solaris, then.
     
    #23
  4. Jannis Jacobsen

    Jannis Jacobsen Active Member

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    The HBA in the server is plain straight through IT mode?
    Boot rom has been removed etc?

    -j
     
    #24
  5. Stril

    Stril Member

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    Hi!

    It's a"real" hba, not a raid controller, so: yes.
     
    #25
  6. zxv

    zxv The more I C, the less I see.

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    Phoronix did a much more thorough comparison recently:
    FreeBSD ZFS vs. TrueOS ZoF vs. DragonFlyBSD HAMMER2 vs. ZFS On Linux Benchmarks - Phoronix

    As just one data point, I did a quick comparison of stat() calls
    ZFS vs EXT4 on Debian Buster alpha4, on a DL380p.
    I chose Debian buster because their contrib repo has zfs 0.7.12.

    With a directory tree holding 480,000 files:
    time find . -ctime 1 >/dev/null
    EXT4: real 0m1.930s user 0m0.431s sys 0m1.493s
    ZFS: real 0m3.326s user 0m0.495s sys 0m2.825s

    EXT4 and ZFS were each on a single 10K WD3000BLFS SATA drive on
    a HP P420i controller, in raid mode, as a single drive raid0 volume.
    Even though the newer hpsa driver handles the P420i, you can still
    get smart data via "smartctl -a -d cciss,0 /dev/sdb".

    I think my results are fairly consistent with what Phoronix shows.
     
    #26
  7. Stril

    Stril Member

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    Hi!

    I think, I found the problem: it must be something related to the ActiveDirectory-Permissions:

    If I disable AD-permissions, the directory-scan speeds up from 2 minutes to 8s.
     
    #27
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