again multipathing cluster with nexenta

[copymaster]

Hi all

can someone please explain what is the benefit from usin multipathing?

And even more important:

do i need to configure multipathing only on the master (and the nodes are replicated automatically) or do i need to configure every node seperately??

And how?

thank you

 

[spirit]

Hi, multipathing must be configured on each node manually.

benefits : you can aggregate bandwidth (1gb/s + 1gb/s), and have redundancy (2 networks switchs with 2 ethernet links):

apt-get install multipath-tools

/etc/multipath.conf (for nexenta)

#
# This is a template multipath-tools configuration file
# Uncomment the lines relevent to your environment
#
defaults {
        udev_dir                /dev
        polling_interval        2
        selector                "round-robin 0"
        path_grouping_policy    multibus
        getuid_callout          "/lib/udev/scsi_id -g -u -d /dev/%n"
        prio_callout            /bin/true
        path_checker            directio
        rr_min_io               100
        rr_weight               priorities
        failback                immediate
        no_path_retry           30
        user_friendly_names     no
}
blacklist {
       wwid 26353900f02796769
        devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
        devnode "^hd[a-z][[0-9]*]"
        devnode "^cciss!c[0-9]d[0-9]*[p[0-9]*]"
        devnode "^sd[a-b][[0-9]*]"

        device {
                vendor DEC.*
                product MSA[15]00
        }
}
blacklist_exceptions {
       devnode "^dasd[c-d]+[0-9]*"
       wwid    "IBM.75000000092461.4d00.34"
}

devices {
        device {
                vendor                  "NEXENTA"
                product                 "COMSTAR"
                path_grouping_policy    group_by_serial
                path_checker            tur
                path_selector           "round-robin 0"
                hardware_handler        "0"
                failback                immediate
                rr_weight               uniform
                no_path_retry           queue
                rr_min_io               100
        }
}

 

[copymaster]

Thanks.

my NEXENTA has 6 NICS, each of my 3 Clusterservers has 4 NICS.

I use ISCSI AND CIFS on nexenta. How would i configure my clusternodes to have best bandwidth??

Is it possible to configure nexenta to use 4 NICS for ISCSI and 2 NICS for CIFS using Multipathing with 4Gbit/2Gbit ??
And is it possible to configure each clusternode to have 2 Nics for ISCI and 2 Nics for CIFS with 2Gbit/2Gbit)???

Actual i use 802.3ad for ISCSI and it brings a little performance improvement (depends on MAC address even or odd)
in this setup i use 4 NICS NExenta for an aggregate and 2 NICS from each clusternode as bond0

unfortunately, if i try to use 2 other NICS from nexenta as a aggregate and 2 NICS from each clusternode as 802.3.ad bound to vmbr0 , i can not see any performance improvement.