# sanlun lun show all

controller(7mode/E-Series)/            device     host               lun
vserver(cDOT/FlashRay)   lun-pathname  filename   adapter  protocol  size    Product
------------------------------------------------------------------------------------
data_vserver          /vol/vol1/lun1   /dev/sdb   host16   FCP       120.0g  cDOT
data_vserver          /vol/vol1/lun1   /dev/sdc   host15   FCP       120.0g  cDOT
data_vserver          /vol/vol2/lun2   /dev/sdd   host16   FCP       120.0g  cDOT
data_vserver          /vol/vol2/lun2   /dev/sde   host15   FCP       120.0g  cDOT

# multipath -ll
3600a09803831347657244e527766394e dm-5 NETAPP,LUN C-Mode
size=80G features='4 queue_if_no_path pg_init_retries 50 retain_attached_hw_handle' hwhandler='1 alua' wp=rw
|-+- policy='service-time 0' prio=50 status=active
| |- 11:0:1:0 sdj 8:144 active ready running
| |- 11:0:2:0 sdr 65:16 active ready running
|-+- policy='service-time 0' prio=10 status=enabled
|- 11:0:0:0 sdb 8:i6 active ready running
|- 12:0:0:0 sdz 65:144 active ready running

chkconfig multipathd on
/etc/init.d/multipathd start

blacklist {
        wwid <DevId>
        devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
        devnode "^hd[a-z]"
        devnode "^cciss.*"
}

+
`sda` is the local SCSI disk that you want to add to the blacklist.

. Add the `WWID` to the blacklist stanza in `/etc/multipath.conf`:
[source,cli]
+

Always check your `/etc/multipath.conf` file, especially in the defaults section, for legacy settings that might be overriding default settings.

The following table demonstrates the critical `multipathd` parameters for ONTAP LUNs and the required values. If a host is connected to LUNs from other vendors and any of these parameters are overridden, they must be corrected by later stanzas in the `multipath.conf` file that apply specifically to ONTAP LUNs. Without this correction, the ONTAP LUNs might not work as expected. You should only override these defaults in consultation with NetApp, the OS vendor, or both, and only when the impact is fully understood.

//ONTAPDOC-2578 9-Dec-2024
//ONTAPDOC-2561 25-Nov-202


[cols=2*,options="header"]
|===
| Parameter
| Setting
| detect_prio | yes
| dev_loss_tmo | "infinity"
| failback | immediate
| fast_io_fail_tmo | 5
| features | "3 queue_if_no_path pg_init_retries 50"
| flush_on_last_del | "yes"
| hardware_handler | "0"
| path_checker | "tur"
| path_grouping_policy | "group_by_prio"
| path_selector | "service-time 0"
| polling_interval | 5
| prio | "ontap"
| product | LUN.*
| retain_attached_hw_handler | yes
| rr_weight | "uniform"
| user_friendly_names | no
| vendor | NETAPP
|===

.Example

The following example shows how to correct an overridden default. In this case, the `multipath.conf` file defines values for `path_checker` and `detect_prio` that are not compatible with ONTAP LUNs.
If they cannot be removed because of other SAN arrays still attached to the host, these parameters can be corrected specifically for ONTAP LUNs with a device stanza.

NOTE: To configure Oracle Linux 7.0 Red Hat Enterprise Kernel (RHCK), use the link:hu_rhel_70.html#recommended-settings[recommended settings] for Red Hat Enterprise Linux (RHEL) 7.0.

== Known issues

The Oracle Linux 7.0 with ONTAP release has the following known issues:

[cols=3*,options="header"]
|===
| NetApp Bug ID
| Title
| Description
| link:https://mysupport.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=901558[901558^] | OL7.0 : Host loses all paths to the lun and hangs due to "RSCN timeout" error on OL 7.0 UEK r3U5 Beta on Emulex 8G(LPe12002) host | You might observe that the Emulex 8G(LPe12002) host hangs and there is a high I/O outage during storage failover operations with I/O. You might observe paths not recovering, which is a result of the RSCN timeout, due to which the host loses all the paths and hangs. Probability of hitting this issue is high.
| link:https://mysupport.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=901557[901557^] | OL 7.0: High IO outage observed on QLogic 8G FC (QLE2562) SAN host during storage failover operations with IO | You might observe high IO outage on QLogic 8G FC (QLE2562) host during storage failover operations with IO. Aborts and Device resets manifests as IO outage on the host. Probability of hitting this IO outage is high.
| link:https://mysupport.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=894766[894766^] |  OL7.0: Dracut fails to include scsi_dh_alua.ko module in initramfs on UEKR3U5 alpha | The scsi_dh_alua module might not load even after adding the parameter "rdloaddriver=scsi_dh_alua" in the kernel command line and creating Dracut. As a result, ALUA is not enabled for NetApp LUNs as recommended.
| link:https://mysupport.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=894796[894796^] | Anaconda displays an iSCSI login failure message although logins are successful during OL 7.0 OS installation |  When you are installing OL 7.0, the anaconda installation screen displays that iSCSI login to multiple target IPs have failed though the iSCSI logins are successful. Anaconda displays following error message:
 "Node Login Failed"
 You will observe this error only when you select multiple target IPs for iSCSI login.
 You can continue the OS installation by clicking the "ok" button. This bug does not hamper either the iSCSI or the OL 7.0 OS installation.
| link:https://mysupport.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=894771[894771^] | OL7.0 : Anaconda does not add bootdev argument in kernel cmd line to set IP address for iSCSI SANboot OS install | Anaconda does not add a bootdev argument in the kernel command line where you set the IPv4 address during the OL 7.0 OS installation on an iSCSI multipath'd LUN. Owing to this, you cannot assign IP addresses to any of the Ethernet interfaces that were configured to establish iSCSI sessions with the storage subsystem during the OL 7.0 boot. Since iSCSI sessions are not established, the root LUN is not discovered when the OS boots and hence the OS boot fails.
| link:https://mysupport.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=916501[916501^] |	Qlogic 10G FCoE (QLE8152) host kernel crash observed during storage failover operations with IO | You may observe a kernel crash in Qlogic driver module on 10G FCoE Qlogic (QLE8152) host. The crash occurs during storage failover operations with IO. Probability of hitting this crash is high which leads to longer IO outage on the host.
|===

// 2024 SEP 2, ONTAPDOC-2345