Hello, I'm configuring an hypervisor for iSCSI Dell PS Series It is a CentOS 7.3 + updates server. The server has been already added to oVirt as a node, but without any storage domain configured yet. It has access to one lun that will become the storage domain one. Default oVirt generated multipath.conf is like this: defaults { polling_interval 5 no_path_retry fail user_friendly_names no flush_on_last_del yes fast_io_fail_tmo 5 dev_loss_tmo 30 max_fds 4096 } devices { device { # These settings overrides built-in devices settings. It does not apply # to devices without built-in settings (these use the settings in the # "defaults" section), or to devices defined in the "devices" section. # Note: This is not available yet on Fedora 21. For more info see # https://bugzilla.redhat.com/1253799 all_devs yes no_path_retry fail } } Apparently in device-mapper-multipath there is no builtin for this combination Vendor: EQLOGIC Model: 100E-00 Rev: 8.1 So, with the oVirt provided configuration a "show config" for multipath reports something like this at the end: polling_interval 5 path_selector "service-time 0" path_grouping_policy "failover" path_checker "directio" rr_min_io_rq 1 max_fds 4096 rr_weight "uniform" failback "manual" features "0" and multipath layout this way [root@ov300 etc]# multipath -l 364817197b5dfd0e5538d959702249b1c dm-3 EQLOGIC ,100E-00 size=1.0T features='0' hwhandler='0' wp=rw |-+- policy='service-time 0' prio=0 status=active | `- 7:0:0:0 sde 8:64 active undef running `-+- policy='service-time 0' prio=0 status=enabled `- 8:0:0:0 sdf 8:80 active undef running [root@ov300 etc]# Following recommendations from Dell here: http://en.community.dell.com/techcenter/extras/m/white_papers/20442422 I should put into defaults section these directives: defaults { polling_interval 10 path_selector "round-robin 0" path_grouping_policy multibus path_checker tur rr_min_io_rq 10 max_fds 8192 rr_weight priorities failback immediate features 0 } I'm trying to mix EQL and oVirt reccomendations to have the best for my use and arrived at this config (plus a blacklist section with my internal hd and my flash wwids that is not relevant here): # VDSM REVISION 1.3 # VDSM PRIVATE defaults { polling_interval 5 no_path_retry fail user_friendly_names no flush_on_last_del yes fast_io_fail_tmo 5 dev_loss_tmo 30 # Default oVirt value overwritten # max_fds 4096 # max_fds 8192 } devices { device { # These settings overrides built-in devices settings. It does not apply # to devices without built-in settings (these use the settings in the # "defaults" section), or to devices defined in the "devices" section. # Note: This is not available yet on Fedora 21. For more info see # https://bugzilla.redhat.com/1253799 all_devs yes no_path_retry fail } device { vendor "EQLOGIC" product "100E-00" # Default EQL configuration overwritten by oVirt default # polling_interval 10 # path_selector "round-robin 0" path_grouping_policy multibus path_checker tur rr_min_io_rq 10 rr_weight priorities failback immediate features "0" } } After activating this config I have this mutipath layout [root@ov300 etc]# multipath -l 364817197b5dfd0e5538d959702249b1c dm-3 EQLOGIC ,100E-00 size=1.0T features='0' hwhandler='0' wp=rw `-+- policy='round-robin 0' prio=0 status=active |- 7:0:0:0 sde 8:64 active undef running `- 8:0:0:0 sdf 8:80 active undef running [root@ov300 etc]# NOTE: at this moment the storage is not yet configured as a storage domain. I also changed /etc/iscsi/iscsd.conf and sysctl.d parameters as from EQL doc indications
From an iSCSI initiator point of view:
[root@ov300 ~]# iscsiadm -m session tcp: [1] 10.10.100.9:3260,1 iqn.2001-05.com.equallogic:4-771816-e5d0dfb59-1c9b240297958d53-ovsd3910 (non-flash) tcp: [2] 10.10.100.9:3260,1 iqn.2001-05.com.equallogic:4-771816-e5d0dfb59-1c9b240297958d53-ovsd3910 (non-flash) [root@ov300 ~]# [root@ov300 ~]# iscsiadm -m session -P 1 Target: iqn.2001-05.com.equallogic:4-771816-e5d0dfb59-1c9b240297958d53-ovsd3910 (non-flash) Current Portal: 10.10.100.41:3260,1 Persistent Portal: 10.10.100.9:3260,1 ********** Interface: ********** Iface Name: ip1p1 Iface Transport: tcp Iface Initiatorname: iqn.1994-05.com.redhat:f2d7fc1e2fc Iface IPaddress: 10.10.100.87 Iface HWaddress: <empty> Iface Netdev: <empty> SID: 1 iSCSI Connection State: LOGGED IN iSCSI Session State: LOGGED_IN Internal iscsid Session State: NO CHANGE Current Portal: 10.10.100.42:3260,1 Persistent Portal: 10.10.100.9:3260,1 ********** Interface: ********** Iface Name: ip1p2 Iface Transport: tcp Iface Initiatorname: iqn.1994-05.com.redhat:f2d7fc1e2fc Iface IPaddress: 10.10.100.87 Iface HWaddress: <empty> Iface Netdev: <empty> SID: 2 iSCSI Connection State: LOGGED IN iSCSI Session State: LOGGED_IN Internal iscsid Session State: NO CHANGE [root@ov300 ~]# Do you think it is ok? Thanks for any comments, Gianluca