# 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

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"
| no_path_retry | queue
| path_checker | "tur"
| path_grouping_policy | "group_by_prio"
| path_selector | "round-robin 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 `no_path_retry` 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.

=== Configure KVM settings

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

//ONTAPDOC-2561 5-Dec-2024

[[known-problems-and-limitations]]
== Known issues

The RHEL 6.6 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=863878[863878^] | Kernel crash occurs with RHEL 6U6 host during storage failures | You might observe kernel crash on RHEL 6U6 host during storage/fabric.
| link:https://mysupport.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=852674[1076584^] | IO stall up to 300 sec seen with QLogic 16G FC (QLE2672) host during storage failures in RHEL 6U4 |You might observe an IO stall up to 300 sec on QLogic 16G FC (QLE2672) host during storage/fabric failures.
| link:https://mysupport.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=795684[795684^] | RHEL6 U5 multipathd incorrectly group multipath maps during MoD and storage failover fault operations |You might observe an incorrect path grouping on LUNs during LUN move on demand operation along with storage faults. During LUN move operation multipath path priorities will change and multipath is unable to reloads the device table due to device failure caused by storage fault. This leads to incorrect path grouping.
|===

// 2024 SEP 2, ONTAPDOC-2345