Ubuntu 20.04 multipath configuration

Question

I just installed a new Ubuntu 20.04 server as a virtual machine on an esx-Server. When I look into systemlog I see lots of multipath entries.

multipathd[651]: sda: add missing path
multipathd[651]: sda: failed to get udev uid: Invalid argument
multipathd[651]: sda: failed to get sysfs uid: Invalid argument
multipathd[651]: sda: failed to get sgio uid: No such file or directory
multipathd[651]: sda: add missing path
multipathd[651]: sda: failed to get udev uid: Invalid argument
multipathd[651]: sda: failed to get sysfs uid: Invalid argument
multipathd[651]: sda: failed to get sgio uid: No such file or directory

I think multipath is just not configured and my question is if I can disable multipath. Since I checked this on several Ubuntu 20.04 servers multipath is enabled by default.

Does it make sense to activate multipath?

score 62 · Answer 1 · edited Feb 14 '24 at 03:23

62

Through this, I have resolved my issue:

Run vi /etc/multipath.conf and add this to the file:

defaults {
    user_friendly_names yes
}
blacklist {
    device {
        vendor "VMware"
        product "Virtual disk"
    }
}

Restart the multipath-tools service:
```
sudo systemctl restart multipath-tools
```

edited Feb 14 '24 at 03:23

gerardw

521

answered May 27 '21 at 10:17

Sulaiman

721

score 45 · Answer 2 · answered Jun 13 '20 at 10:55

There is a SUSE linux KB on the topic - https://www.suse.com/support/kb/doc/?id=000016951. The problem is that VMWare by default doesn't provide information needed by udev to generate /dev/disk/by-id entries. Apart from ESX, VMWare Workstation (my case) is also affected. The resolution is to put

disk.EnableUUID = "TRUE"

to the virtual machine definition, i.e. into the *.vmx file or via Edit Settings -> Options tab -> General -> Configuration Parameters in ESX UI.

After rebooting VM with this parameter set, the disk are visible in /dev/disk/by-id and multipathd doesn't complain anymore.

score 30 · Answer 3 · answered Aug 25 '20 at 06:46

If you dont have access to your host ESX you can add the following lines to your /etc/multipath.conf file which also blacklists common other devices like CDRom drives etc.

defaults {
    user_friendly_names yes
}
blacklist {
    devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st|sda)[0-9]*"
}

score 3 · Answer 4 · edited Dec 12 '20 at 17:11

Adding the below into the guest vm parameters worked for me. The syslog is no longer complaining and the server appears to be staying up.

disk.EnableUUID = "TRUE"

This is added to the virtual machine definition, i.e. into the *.vmx file, or via Edit Settings -> Options tab -> General -> Configuration Parameters in ESX UI.

Ubuntu 20.04 running apache and Wordpress php-7.4-fpm

score 3 · Answer 5 · edited Apr 03 '22 at 20:30

3

If you don't need multipath, turn it off:

systemctl disable multipathd
systemctl stop multipathd

edited Apr 03 '22 at 20:30

BeastOfCaerbannog

16,703

answered Apr 01 '22 at 20:50

Kim

41

score 2 · Answer 6 · edited Jan 27 '21 at 10:06

2

I'd use a:

defaults {
    user_friendly_names yes
}
blacklist {
    devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
    devnode "^sd[a-z]?[0-9]*"
}

for sda, sdb, etc.

edited Jan 27 '21 at 10:06

BeastOfCaerbannog

16,703

answered Jan 27 '21 at 08:28

Michael Schreiber

21

score 1 · Answer 7 · edited Dec 30 '20 at 07:48

1

Here is another way to set it.

Use govc

Setup GOVC_URL first like

export GOVC_URL='https://username:password@vcenter.company.com/sdk'

and set UUID like

govc vm.change -e="disk.EnableUUID=TRUE" -vm='MY_VM_NAME'

One more thing, you have to poweroff and poweron to take effect this change

govc vm.power -off -force VM1
govc vm.power -on -force VM1

edited Dec 30 '20 at 07:48

Tejas Lotlikar

2,985

answered Dec 16 '20 at 23:26

maxisam

111

score -1 · Answer 8 · edited Mar 01 '24 at 09:27

-1

Add these line in /etc/multipath.conf. this works for me all error are gone

blacklist {
        devnode "sda"
}

edited Mar 01 '24 at 09:27

muru

207,228

answered Mar 01 '24 at 08:45

Abdul Basit

1

Ubuntu 20.04 multipath configuration

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