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Is there a guide of how to set multipath for petasan iscsi disk in linux?


shadowlin
67 Posts
April 18, 2018, 6:23 am

I tired to follow the guild from lrbd wiki but It doesn't work out.The documentation sector of petasan has only guide for windows.

 

#1

shadowlin
67 Posts
April 18, 2018, 7:38 am

I figured out the problem was the vendor name.

after using this /etc/multipath.conf setting it works

defaults {
  user_friendly_names yes
}

devices {
  device {
    vendor "(LIO-ORG|PETASAN)"
    product "RBD"
    path_grouping_policy "multibus"
    path_checker "tur"
    features "0"
    hardware_handler "1 alua"
    prio "alua"
    failback "immediate"
    rr_weight "uniform"
    no_path_retry 12
    rr_min_io 100
  }
}

Is there any other setting should be take care of?

 

I also notice dmesg info of following:

[ 617.801221] scsi 7:0:0:0: Direct-Access PETASAN RBD 4.0 PQ: 0 ANSI: 5
[ 617.802071] scsi 8:0:0:0: Direct-Access PETASAN RBD 4.0 PQ: 0 ANSI: 5
[ 617.838207] sd 7:0:0:0: Attached scsi generic sg1 type 0
[ 617.840390] sd 7:0:0:0: [sdb] 21474836481 512-byte logical blocks: (11.0 TB/10.0 TiB)
[ 617.840491] sd 7:0:0:0: [sdb] Write Protect is off
[ 617.840497] sd 7:0:0:0: [sdb] Mode Sense: 43 00 00 08
[ 617.840722] sd 7:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
[ 617.851077] sd 7:0:0:0: [sdb] Attached SCSI disk
[ 617.857993] sd 8:0:0:0: Attached scsi generic sg2 type 0
[ 617.859795] sd 8:0:0:0: [sdc] 21474836481 512-byte logical blocks: (11.0 TB/10.0 TiB)
[ 617.859914] sd 8:0:0:0: [sdc] Write Protect is off
[ 617.859917] sd 8:0:0:0: [sdc] Mode Sense: 43 00 00 08
[ 617.860114] sd 8:0:0:0: [sdc] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
[ 617.871043] sd 8:0:0:0: [sdc] Attached SCSI disk
[ 618.546081] device-mapper: multipath round-robin: version 1.2.0 loaded
[ 618.554183] alua: device handler registered
[ 618.554504] sd 8:0:0:0: alua: supports implicit TPGS
[ 618.554511] sd 8:0:0:0: alua: device naa.6001405fac5cf32d6d63af9949e4a8cb port group 0 rel port 2
[ 618.554516] device-mapper: multipath round-robin: repeat_count > 1 is deprecated, using 1 instead
[ 618.570041] sd 8:0:0:0: alua: transition timeout set to 60 seconds
[ 618.570049] sd 8:0:0:0: alua: port group 00 state A non-preferred supports TOlUSNA
[ 618.616605] device-mapper: multipath round-robin: repeat_count > 1 is deprecated, using 1 instead
[ 618.616642] sd 7:0:0:0: alua: supports implicit TPGS
[ 618.616650] sd 7:0:0:0: alua: device naa.6001405fac5cf32d6d63af9949e4a8cb port group 0 rel port 1
[ 618.616654] device-mapper: multipath round-robin: repeat_count > 1 is deprecated, using 1 instead
[ 618.630160] sd 7:0:0:0: alua: port group 00 state A non-preferred supports TOlUSNA
[ 618.630286] sd 7:0:0:0: alua: port group 00 state A non-preferred supports TOlUSNA

 

Is there anything wrong?

Last edited on April 18, 2018, 9:09 am by shadowlin · #2

admin
2,930 Posts
April 18, 2018, 11:59 am

I would not worry about the warning too much. It seems the mpio package you use is older than the kernel on the client. Try to find a newer package if available. Also try setting

rr_min_io 100 ->
rr_min_io 1
#3

shadowlin
67 Posts
April 18, 2018, 2:37 pm

Thank you.

I did upgrade the kernel of ubuntu 14.0.4 server to 4.12.

I tried to shutdown on path during writing test without float ip.It took about 2mins to failover to another path.Is this because of the client side setting?

#4

admin
2,930 Posts
April 18, 2018, 3:41 pm

For Linux , you can adjust the following values in the open-iscsi configuration:
noop_out_interval
noop_out_timeout
replacement_timeout

The total fail-over time is the total of the above values

you can also over-ride the replacement_timeout via the multi-path config value (if defined):
fast_io_fail_tmo

Last edited on April 18, 2018, 3:41 pm by admin · #5