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SDS / Raw devices RHEL 8

  • 1.  SDS / Raw devices RHEL 8

    Posted 8 days ago
    Hi.

    We have been running 12.10 in SDS mode on RHEL 6.7 for many years now and everything works very well. At the time we started using SDS I asked some questions about this setup in the old forum on the IIUG website, and now the discussion is lost :(
    Is there an archive of it somewhere?  

    Now we are migrating to new servers running RHEL 8.0 so we can upgrade to 14.10.
    On RHEL 6.7 we use raw devices and multipath for our disks. Now the sysadmins who are configuring the new system tell me they have problems with raw devices in RHEL 8. They tell me the 6.7 way of doing things doesn't work in 8.x (they were not very specific).
    Googling "raw devices RHEL 8" does not give any useful results.

    Is anyone using a similar setup in RHEL 8.0? (SDS)?
    Is there a better/other way to use SDS than raw devices / multipath?

    Thanks in advance,
    -Snorri

    ------------------------------
    Snorri Bergmann
    Init ehf.
    Informix DBA
    ------------------------------


  • 2.  RE: SDS / Raw devices RHEL 8

    Posted 8 days ago
    Edited by SangGyu Jeong 8 days ago
    Hi Snorri,
    I have installed informix 14.10.fc3 on centos 8.1.
    After installation, I created a raw device and added dbspace.
    I think it's the same in Red Hat 8.


    root:
    raw /dev/raw/raw1 /dev/sdc
    chown informix:informix /dev/raw/raw1

    informix:
    onspaces -c -d dbs1 -p /dev/raw/raw1 -o 32 -s 5000000



    ------------------------------
    SangGyu Jeong
    Software Engineer
    Infrasoft
    Seoul Korea, Republic of
    ------------------------------


  • 3.  RE: SDS / Raw devices RHEL 8

    Posted 8 days ago
    Hi Snorri,

    I always use raw devices concerning security as they don't appear can't be deleted! About performance it is relative as they are new features that can improve performance...
    About configuration on RHEL 8 is similar to RHEL 7, create one file /etc/udev/rules.d/60-raw.rules and put something like this, one line for each device:

    ACTION=="add", KERNEL=="sdX1", OWNER="informix", GROUP="informix", MODE="0660", RUN+="/bin/raw /dev/raw/raw1 %N"

    ..

    ACTION=="add", KERNEL=="sdX6", OWNER="informix", GROUP="informix", MODE="0660", RUN+="/bin/raw /dev/raw/raw? %N"
    ACTION=="add", KERNEL=="raw?", OWNER="informix", GROUP="informix", MODE="0660"

    To activate use the command: udevadm trigger --action=add

    If you use LVM use this on file and replace VG and LV names with your settings [lvs] command to see them:
    ACTION=="add", ENV{DM_VG_NAME}=="vg_test", ENV{DM_LV_NAME}=="lv_test1", RUN+="/bin/raw /dev/raw/raw1 %N"
    ...
    ACTION=="add", KERNEL=="raw?", OWNER="informix", GROUP="informix", MODE="0660"

    SP

    ------------------------------
    Sergio Peres
    AIRC
    Coimbra
    ------------------------------



  • 4.  RE: SDS / Raw devices RHEL 8

    Posted 3 days ago
    Thank you guys for your input. 
    Now I have my system up and running.

    Best regards,
    -Snorri

    ------------------------------
    Snorri Bergmann
    ------------------------------