Use SUSE Linux Enterprise Server 15 SP4 with ONTAP
You can use the ONTAP SAN host configuration settings to configure SUSE Linux Enterprise Server 15 SP4 with ONTAP as the target.
Install the Linux Unified Host Utilities
The NetApp Linux Unified Host Utilities software package is available on the NetApp Support Site in a 32-bit and 64-bit .rpm file. If you do not know which file is right for your configuration, use the NetApp Interoperability Matrix Tool to verify which one you need.
NetApp strongly recommends installing the Linux Unified Host Utilities, but it is not mandatory. The utilities do not change any settings on your Linux host. The utilities improve management and assist NetApp customer support in gathering information about your configuration.
If you have a version of Linux Unified Host Utilities currently installed you should upgrade it or, you should remove it and use the following steps to install the latest version.
-
Download the 32-bit or 64-bit Linux Unified Host Utilities software package from the NetApp Support Site Site to your host.
-
Use the following command to install the software package:
rpm -ivh netapp_linux_unified_host_utilities-7-1.x86_64
You can use the configuration settings provided in this document to configure cloud clients connected to Cloud Volumes ONTAP and Amazon FSx for ONTAP. |
SAN Toolkit
The toolkit is installed automatically when you install the NetApp Host Utilities package. This kit provides the sanlun
utility, which helps you manage LUNs and HBAs. The sanlun
command returns information about the LUNs mapped to your host, multipathing, and information necessary to create initiator groups.
In the following example, the sanlun lun show
command returns LUN information.
# sanlun lun show all
Example output:
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
SAN booting
If you decide to use SAN booting, it must be supported by your configuration. You can use the NetApp Interoperability Matrix Tool to verify that your OS, HBA, HBA firmware and the HBA boot BIOS, and ONTAP version are supported.
-
Map the SAN boot LUN to the host.
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Verify that multiple paths are available.
Multiple paths become available after the host OS is up and running on the paths. -
Enable SAN booting in the server BIOS for the ports to which the SAN boot LUN is mapped.
For information on how to enable the HBA BIOS, see your vendor-specific documentation.
-
Reboot the host to verify that the boot is successful.
Multipathing
For SUSE Linux Enterprise Server 15 SP4 the /etc/multipath.conf
file must exist, but you do not need to make specific changes to the file. SUSE Linux Enterprise Server 15 SP4 is compiled with all settings required to recognize and correctly manage ONTAP LUNs.
You can use the multipath -ll
command to verify the settings for your ONTAP LUNs.
The following sections provide sample multipath output for a LUN mapped to ASA and non-ASA personas.
All SAN Array configurations
In All SAN Array (ASA) configurations, all paths to a given LUN are active and optimized. This improves performance by serving I/O operations through all paths at the same time.
The following example displays the correct output for an ONTAP LUN:
# multipath -ll 3600a09803831347657244e527766394e dm-5 NETAPP,LUN C-Mode size=80G features='3 queue_if_no_path pg_init_retries 50' hwhandler='1 alua' wp=rw `-+- policy='service-time 0' prio=50 status=active |- 3:0:7:9 sdco 69:192 active ready running |- 3:0:8:9 sddi 71:0 active ready running |- 14:0:8:9 sdjq 65:320 active ready running `- 14:0:7:9 sdiw 8:256 active ready running
Do not use an excessive number of paths to a single LUN. No more than four paths should be required. More than eight paths might cause path issues during storage failures. |
Non-ASA configurations
For non-ASA configurations, there should be two groups of paths with different priorities. The paths with the higher priorities are Active/Optimized, meaning they are serviced by the controller where the aggregate is located. The paths with the lower priorities are active but are non-optimized because they are served from a different controller. The non-optimized paths are only used when no optimized paths are available.
The following example displays the correct output for an ONTAP LUN with two Active/Optimized paths and two Active/Non-Optimized paths:
# multipath -ll 3600a09803831347657244e527766394e dm-5 NETAPP,LUN C-Mode size=80G features='3 queue_if_no_path pg_init_retries 50' hwhandler='1 alua' wp=rw |-+- policy='service-time 0' prio=50 status=active | |- 3:0:3:0 sdd 8:48 active ready running | |- 3:0:4:0 sdx 65:112 active ready running `-+- policy='service-time 0' prio=10 status=enabled |- 14:0:2:0 sdfk 130:96 active ready running `- 14:0:5:0 sdgz 132:240 active ready running
Do not use an excessive number of paths to a single LUN. No more than four paths should be required. More than eight paths might cause path issues during storage failures. |
Recommended settings
SUSE Linux Enterprise Server 15 SP4 OS is compiled to recognize ONTAP LUNs and automatically set all configuration parameters correctly for both ASA and non-ASA configuration.
The multipath.conf
file must exist for the multipath daemon to start, but you can create an empty, zero-byte file by using the command:
touch /etc/multipath.conf
.
The first time you create this file, you might need to enable and start the multipath services.
There is no requirement to add anything directly to the multipath.conf
file, unless you have devices that you do not want to be managed by multipath or you have existing settings that override defaults.
You can add the following syntax to the multipath.conf
file to exclude the unwanted devices.
Replace <DevId>
with the WWID
string of the device you want to exclude. Use the following command to determine the WWID
:
In this example, sda
is the local SCSI disk that we need to add to the blacklist.
-
Run the following command to determine the
WWID
:# /usr/lib/udev/scsi_id -gud /dev/sda 360030057024d0730239134810c0cb833
-
Add the
WWID
value to the blacklist stanza in the/etc/multipath.conf
file:blacklist { wwid 360030057024d0730239134810c0cb833 devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*" devnode "^hd[a-z]" devnode "^cciss.*" }
You should always check your /etc/multipath.conf
file for legacy settings, especially in the defaults section, that might be overriding default settings.
The table below shows 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 will need to be corrected by later stanzas in multipath.conf
that apply specifically to ONTAP LUNs. If this is not done, the ONTAP LUNs might not work as expected. These defaults should only be overridden in consultation with NetApp and/or OS vendor and only when the impact is fully understood.
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 |
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 these parameters cannot be removed because other SAN arrays are still attached to the host, they can instead be corrected specifically for ONTAP LUNs with a device stanza.
defaults { path_checker readsector0 no_path_retry fail } devices { device { vendor "NETAPP " product "LUN.*" no_path_retry queue path_checker tur } }
Known issues
There are no known issues for the SUSE Linux Enterprise Server 15 SP4 with ONTAP release.