7:25 p.m.
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