{{tag>Brouillon SAN Disque Réseau}}

= Notes Multipath I/O MPIO


Voir :
* [[https://en.wikipedia.org/wiki/Multipath_I/O|Multipath I/O (MPIO)]]
* https://pve.proxmox.com/wiki/ISCSI_Multipath
* https://www.suse.com/documentation/sles-12/stor_admin/data/sec_multipath_lvm.html
* https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/DM_Multipath/mpio_setup.html
* http://www.netexpertise.eu/en/systems/linux/multipathed-iscsi-san-disks-on-linux.html
* http://linux.dell.com/files/whitepapers/iSCSI_Multipathing_in_Ubuntu_Server.pdf

Conf GNU/Linux:
* https://support.purestorage.com/Solutions/Linux/Linux_Reference/Linux_Recommended_Settings
* https://support.purestorage.com/Solutions/Linux/Installing_and_Configuring/Configuring_Linux_Host_for_iSCSI_with_FlashArray
* https://storageconsortium.de/content/sites/default/files/downloads/purestorage_WP_Oracle_Best_Practices.pdf
* https://pure-storage-openstack-docs.readthedocs.io/en/wallaby/swift/section_swift-partitioning.html


== Si LVM


<code bash>
sed -i -e "s/use_lvmetad \= 1/use_lvmetad \= 0/g" /etc/lvm/lvm.conf
systemctl stop lvm2-lvmetad.service
systemctl stop lvm2-lvmetad.socket
#mkinitrd -f /boot/initrd-$(uname -r).img $(uname -r)
dracut -H -f /boot/initramfs-$(uname -r).img  $(uname -r)
yum install device-mapper-multipath
#dracut -f --add-drivers multipath
</code>

// Voir gdisk et parted pour GPT //
<code ->
# fdisk /dev/sdc
t
8e (LVM Linux)
w
</code>

Création PV, VG, LV => voir LVM

== Suite

<code bash>
multipath -ll
modprobe dm_multipath
/sbin/mpathconf
systemctl start multipathd
</code>


''/etc/multipath.conf''
<code c>
defaults {
        user_friendly_names yes
        find_multipaths yes
}
</code>

Autre conf possible

<code ->
# /lib/udev/scsi_id -g -u -d /dev/disk/by-path/*iscsi*
14945540000000000ed34fecd6b19c9dac92c6a5ccdddce57
</code>

''/etc/multipath.conf''
<code c>
blacklist {
        wwid .*
}

blacklist_exceptions {
        wwid "14945540000000000ed34fecd6b19c9dac92c6a5ccdddce57"
}
</code>

<code bash>
multipath -r
multipath -ll
</code>


== Autres

<code bash>
dracut -f --add-drivers multipath
</code>

<code bash>
multipath -F
multipath -v2
multipath -r
</code>


=== Exemple

<code bash>
multipath -ll
multipathd show paths
</code>

/etc/multipath.conf

<code ->
more /sys/class/fc_host/host?/port_state
::::::::::::::
/sys/class/fc_host/host2/port_state
::::::::::::::
Online
::::::::::::::
/sys/class/fc_host/host3/port_state
::::::::::::::
Online
</code>

<code ->
blacklist {
        devnode "^(ram|raw|loop|fd|dm-|sr|scd|st)[0-9]*"
        devnode "^hd[a-z]"
        devnode "^fio[a-z]"
        devnode "^dcssblk[0-9]*"
        device {
                vendor "DGC"
                product "LUNZ"
        }
        device {
                vendor "IBM"
                product "S/390.*"
        }
        # don't count normal SATA devices as multipaths
        device {
                vendor  "ATA"
        }
        # don't count 3ware devices as multipaths
        device {
                vendor  "3ware"
                }
        device {
                vendor  "AMCC"
        }
                # nor highpoint devices

blacklist {
        devnode "^(ram|raw|loop|fd|dm-|sr|scd|st)[0-9]*"
        devnode "^hd[a-z]"
        devnode "^fio[a-z]"
        devnode "^dcssblk[0-9]*"
        device {
                vendor "DGC"
                product "LUNZ"
        }
        device {
                vendor "IBM"
                product "S/390.*"
        }
        # don't count normal SATA devices as multipaths
        device {
                vendor  "ATA"
        }
        # don't count 3ware devices as multipaths
        device {
                vendor  "3ware"
                }
        device {
                vendor  "AMCC"
        }
                # nor highpoint devices
        device {
                vendor  "HPT"
        } 
</code>