In my perspective, the ovirt developers put very general configuration of
multipath.conf file, which in their opinion should work with as much as
posslible arrays.
So you should modify this file and try to do some tests, plug in, plug out
links etc.
If you want to get luns picture, you should better use: iscsiadm -m session
-P 3.
2017-03-28 18:25 GMT+02:00 Gianluca Cecchi <gianluca.cecchi(a)gmail.com>:
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
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