# 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       80.0g  cDOT
data_vserver          /vol/vol1/lun1   /dev/sdc   host15   FCP       80.0g  cDOT
data_vserver          /vol/vol2/lun2   /dev/sdd   host16   FCP       80.0g  cDOT
data_vserver          /vol/vol2/lun2   /dev/sde   host15   FCP       80.0g  cDOT

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 | 2 pg_init_retries 50
| flush_on_last_del | yes
| hardware_handler | 0
| no_path_retry | queue
| 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 demonstrates how to correct an overridden default. In this case, the `multipath.conf` file defines values for `path_checker` and `no_path_retry` that are not compatible with ONTAP LUNs. If they cannot be removed because other SAN arrays are still attached to the host, these parameters can be corrected specifically for ONTAP LUNs with a device stanza.

NOTE: To configure Oracle Linux 8.8 Red Hat Enterprise Kernel, use the link:hu_rhel_88.html#recommended-settings[recommended settings] for Red Hat Enterprise Linux (RHEL) 8.8.

== KVM settings

You can also use the recommended settings to configure a Kernel-based Virtual Machine (KVM). There are no changes required to configure a KVM as the LUN is mapped to the hypervisor.

== Known issues

There are no known issues for the Oracle Linux 8.8 with ONTAP release.