Saturday, December 9, 2017

Disabling dm multipathing on RHEL7

If you want to use any other third party multipathing software apart from DM (Linux native multipathing) then to disable DM follow below steps:

1. Blacklist all devices in /etc/multipath.conf. Edit /etc/multipath.conf so that it contains only the following lines:

blacklist {
devnode "*"
}


2. Ensure dm-multipath does not start automatically at boot.

# systemctl disable multipathd.service

# systemctl list-unit-files | grep multipath
 multipathd.service                          disabled


3. Recreate initramfs so that dm-multipath is excluded from initramfs.

# dracut /boot/initramfs-wo-DM-$(uname -r).img $(uname -r)

Take a backup of existing /boot/initramfs-$(uname –r).img file and rename the above created initrmafs file to the name of orginal initramfs file.


4. Reboot the host with the new initramfs image and ensure dm-multipath does not have

5. To check if any devices are configured

# multipath -ll --- should not return any dm devices

How to get HBA/LUN/Paths information on ESXi 6.x ?

1. To check how many HBA's are installed and which are all having connectivity

# esxcli storage core adapter list
HBA Name  Driver      Link State  UID                                   Capabilities                         Description                                                    
--------  ----------  ----------  ------------------------------------  -----------------------------------  ---------------------------------------------------------------------------------------
vmhba0    hpdsa       link-n/a    unknown.vmhba0                                                             (0000:01:00.7) Hewlett Packard Enterprise HPE|Dynamic Smart Array B140i RAID Controller
vmhba1    lpfc        link-n/a    fc.20001402ecec2db2:10001402ecec2db2  Second Level Lun ID                  (0000:04:00.0) Emulex Corporation Emulex LightPulse LPe16000 PCIe Fibre Channel Adapter
vmhba2    lpfc        link-n/a    fc.20001402ecec2db3:10001402ecec2db3  Second Level Lun ID                  (0000:04:00.1) Emulex Corporation Emulex LightPulse LPe16000 PCIe Fibre Channel Adapter
vmhba3    qlnativefc  link-up     fc.500143803137785d:500143803137785c  Data Integrity, Second Level Lun ID  (0000:83:00.0) QLogic Corp 2600 Series 16Gb Fibre Channel to PCI Express HBA
vmhba4    qlnativefc  link-up     fc.500143803137785f:500143803137785e  Data Integrity, Second Level Lun ID  (0000:83:00.1) QLogic Corp 2600 Series 16Gb Fibre Channel to PCI Express HBA


2. To check brief info about WWNN/WWPN/Port_Speed/Status/Model/Firmware and Driver version

# esxcli storage san fc list
   Adapter: vmhba3
   Port ID: 010A00
   Node Name: 50:01:43:80:31:37:78:5d
   Port Name: 50:01:43:80:31:37:78:5c
   Speed: 16 Gbps
   Port Type: NPort
   Port State: ONLINE
   Model Description: Synergy 3830C 1
   Hardware Version: CU0410431-01  G
   OptionROM Version: 3.43
   Firmware Version: 8.05.60 (d0d5)
   Driver Name: qlnativefc
   DriverVersion: 2.1.57.0
 
 
3. To check multipath details for a device

# esxcli storage nmp device list

naa.60002ac0000000000000004b0001cb64
   Device Display Name: 3PARdata Fibre Channel Disk (naa.60002ac0000000000000004b0001cb64)
   Storage Array Type: VMW_SATP_ALUA
   Storage Array Type Device Config: {implicit_support=on; explicit_support=off; explicit_allow=on; alua_followover=on; action_OnRetryErrors=off; {TPG_id=1,TPG_state=AO}}
   Path Selection Policy: VMW_PSP_RR
   Path Selection Policy Device Config: {policy=rr,iops=1000,bytes=10485760,useANO=0; lastPathIndex=1: NumIOsPending=0,numBytesPending=0}
   Path Selection Policy Device Custom Config:
   Working Paths: vmhba4:C0:T0:L10, vmhba4:C0:T1:L10, vmhba3:C0:T0:L10, vmhba3:C0:T1:L10
   Is USB: false



4. To check path details for a device 

# esxcli storage core path list
fc.500143803137785f:500143803137785e-fc.2ff70002ac01cb64:21420002ac01cb64-naa.60002ac0000000000000004a0001cb64
   UID: fc.500143803137785f:500143803137785e-fc.2ff70002ac01cb64:21420002ac01cb64-naa.60002ac0000000000000004a0001cb64
   Runtime Name: vmhba4:C0:T1:L9
   Device: naa.60002ac0000000000000004a0001cb64
   Device Display Name: 3PARdata Fibre Channel Disk (naa.60002ac0000000000000004a0001cb64)
   Adapter: vmhba4
   Channel: 0
   Target: 1
   LUN: 9
   Plugin: NMP
   State: active
   Transport: fc
   Adapter Identifier: fc.500143803137785f:500143803137785e
   Target Identifier: fc.2ff70002ac01cb64:21420002ac01cb64
   Adapter Transport Details: WWNN: 50:01:43:80:31:37:78:5f WWPN: 50:01:43:80:31:37:78:5e
   Target Transport Details: WWNN: 2f:f7:00:02:ac:01:cb:64 WWPN: 21:42:00:02:ac:01:cb:64
   Maximum IO Size: 33553920

 
5. More info about each device

# esxcli storage core device list
   
naa.60002ac000000000000000860001cb64
   Display Name: 3PARdata Fibre Channel Disk (naa.60002ac000000000000000860001cb64)
   Has Settable Display Name: true
   Size: 2609152
   Device Type: Direct-Access
   Multipath Plugin: NMP
   Devfs Path: /vmfs/devices/disks/naa.60002ac000000000000000860001cb64
   Vendor: 3PARdata
   Model: VV
   Revision: 3312
   SCSI Level: 6
   Is Pseudo: false
   Status: on
   Is RDM Capable: true
   Is Local: false
   Is Removable: false
   Is SSD: false
   Is VVOL PE: false
   Is Offline: false
   Is Perennially Reserved: false
   Queue Full Sample Size: 32
   Queue Full Threshold: 4
   Thin Provisioning Status: yes
   Attached Filters:
   VAAI Status: supported
   Other UIDs: vml.020005000060002ac000000000000000860001cb64565620202020
   Is Shared Clusterwide: true
   Is Local SAS Device: false
   Is SAS: false
   Is USB: false
   Is Boot USB Device: false
   Is Boot Device: false
   Device Max Queue Depth: 64
   No of outstanding IOs with competing worlds: 32
   Drive Type: unknown
   RAID Level: unknown
   Number of Physical Drives: unknown
   Protection Enabled: false
   PI Activated: false
   PI Type: 0
   PI Protection Mask: T1 T3 T1+DIX T3+DIX
   Supported Guard Types: IP, CRC
   DIX Enabled: false
   DIX Guard Type: NO GUARD SUPPORT
   Emulated DIX/DIF Enabled: false


6. To check active paths :

# esxcfg-mpath -L
vmhba4:C0:T0:L0 state:active naa.60002ac000000000000000050001cb64 vmhba4 0 0 0 NMP active san fc.500143803137785f:500143803137785e fc.2ff70002ac01cb64:20420002ac01cb64
vmhba4:C0:T0:L1 state:active naa.60002ac000000000000000400001cb64 vmhba4 0 0 1 NMP active san fc.500143803137785f:500143803137785e fc.2ff70002ac01cb64:20420002ac01cb64