Multipath iSCSI /dev/mapper device is not created (Proxmox 6)

DiegodelaFuente

Active Member
Aug 25, 2019
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1
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I'm testing a Proxmox 6 environment and I'm having issues trying to configure iSCSI with multipath.

I have a Dell Rc710 (4 onboard 1 Gb nics for VMs and management). And 2 10Gb nics for iSCSI.
I have connected these two nics to a Lenovo De2000h storage.

I have created the Multipath and if I test it I can see up and runing.

root@Mercurio:~# systemctl status -l multipath-tools.service
â multipathd.service - Device-Mapper Multipath Device Controller
Loaded: loaded (/lib/systemd/system/multipathd.service; enabled; vendor preset: enabled)
Active: active (running) since Sun 2019-08-25 02:36:11 -03; 22s ago
Process: 15173 ExecStartPre=/sbin/modprobe -a scsi_dh_alua scsi_dh_emc scsi_dh_rdac dm-multipath (code=exited, status=0/SUCCESS)
Main PID: 15180 (multipathd)
Status: "up"
Tasks: 7
Memory: 11.1M
CGroup: /system.slice/multipathd.service
ââ15180 /sbin/multipathd -d -s

Aug 25 02:36:11 Mercurio systemd[1]: Starting Device-Mapper Multipath Device Controller...
Aug 25 02:36:11 Mercurio multipathd[15180]: --------start up--------
Aug 25 02:36:11 Mercurio multipathd[15180]: read /etc/multipath.conf
Aug 25 02:36:11 Mercurio multipathd[15180]: path checkers start up
Aug 25 02:36:11 Mercurio systemd[1]: Started Device-Mapper Multipath Device Controller.


/etc/multipath.conf

defaults {
polling_interval 2
path_selector "round-robin 0"
path_grouping_policy multibus
uid_attribute ID_SERIAL
rr_min_io 100
failback immediate
no_path_retry queue
user_friendly_names yes
}

blacklist_exceptions {
wwid "3600a098000fd5a7c000000c05d5e0f25"
}
multipaths {
multipath {
wwid "3600a098000fd5a7c000000c05d5e0f25"
alias mpath0
}


root@Mercurio:~# ls -l /dev/mapper/
total 0
crw------- 1 root root 10, 236 Aug 25 01:49 control
lrwxrwxrwx 1 root root 7 Aug 25 01:49 pve-data -> ../dm-4
lrwxrwxrwx 1 root root 7 Aug 25 01:49 pve-data_tdata -> ../dm-3
lrwxrwxrwx 1 root root 7 Aug 25 01:49 pve-data_tmeta -> ../dm-2
lrwxrwxrwx 1 root root 7 Aug 25 01:49 pve-root -> ../dm-1
lrwxrwxrwx 1 root root 7 Aug 25 01:49 pve-swap -> ../dm-0

* There is no mpath0 device

multipath -ll
does not show something

root@Mercurio:~# multipath -v3
===== paths list =====
uuid hcil dev dev_t pri dm_st chk_st vend/prod
3600a098000fd5a7c000000c05d5e0f25 7:0:0:1 sdd 8:48 50 undef undef LENOVO,DE
3600a098000fd5a7c000000c05d5e0f25 8:0:0:1 sde 8:64 10 undef undef LENOVO,DE
Aug 25 02:51:18 | libdevmapper version 1.02.155 (2018-12-18)
Aug 25 02:51:18 | DM multipath kernel driver v1.13.0
Aug 25 02:51:18 | sdd: udev property ID_WWN whitelisted
Aug 25 02:51:18 | sdd: wwid 3600a098000fd5a7c000000c05d5e0f25 whitelisted
Aug 25 02:51:18 | wwid 3600a098000fd5a7c000000c05d5e0f25 not in wwids file, skipping sdd

Aug 25 02:51:18 | sdd: orphan path, only one path
Aug 25 02:51:18 | alua prioritizer refcount 2
Aug 25 02:51:18 | sde: udev property ID_WWN whitelisted
Aug 25 02:51:18 | sde: wwid 3600a098000fd5a7c000000c05d5e0f25 whitelisted
Aug 25 02:51:18 | wwid 3600a098000fd5a7c000000c05d5e0f25 not in wwids file, skipping sde

Aug 25 02:51:18 | sde: orphan path, only one path
Aug 25 02:51:18 | alua prioritizer refcount 1
Aug 25 02:51:18 | unloading alua prioritizer
Aug 25 02:51:18 | unloading const prioritizer
Aug 25 02:51:18 | unloading rdac checker
Aug 25 02:51:18 | unloading tur checker



root@Mercurio:~# lsscsi
[0:0:0:0] cd/dvd TEAC DVD-ROM DV-28SW R.2A /dev/sr0
[2:0:0:0] disk SanDisk Cruzer Glide 3.0 1.00 /dev/sda
[4:0:0:0] disk iDRAC LCDRIVE 0323 /dev/sdc
[5:0:0:0] cd/dvd iDRAC Virtual CD 0323 /dev/sr1
[5:0:0:1] disk iDRAC Virtual Floppy 0323 /dev/sdb
[7:0:0:0] disk LENOVO DE_Series 0851 -
[7:0:0:1] disk LENOVO DE_Series 0851 /dev/sdd
[7:0:0:7] disk LENOVO Universal Xport 0851 -
[8:0:0:0] disk LENOVO DE_Series 0851 -
[8:0:0:1] disk LENOVO DE_Series 0851 /dev/sde
[8:0:0:7] disk LENOVO Universal Xport 0851 -


root@Mercurio:~# /lib/udev/scsi_id -g -u -d /dev/sdd
3600a098000fd5a7c000000c05d5e0f25

Regards
Diego
 
Check your multipath.conf file. Seems one more “}” bracket is missing at the end
 
It was a mistake when copy paste the config file to the post.
Her is the cull config file. I'm still have the issue.


defaults {
polling_interval 2
path_selector "round-robin 0"
path_grouping_policy multibus
uid_attribute ID_SERIAL
rr_min_io 100
failback immediate
no_path_retry queue
user_friendly_names yes
}

blacklist_exceptions {
wwid "3600a098000fd5a7c000000c05d5e0f25"
}
multipaths {
multipath {
wwid "3600a098000fd5a7c000000c05d5e0f25"
alias mpath0
}
}
 
I have installed proxmox 5.4 and made the same configurations as in proxmox 6

now it seems to be working.
Gilberto must be right.

root@Mercurio:~# multipath -ll
mpath0 (3600a098000fd5a7c000000c05d5e0f25) dm-5 LENOVO,DE_Series
size=13T features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw
`-+- policy='round-robin 0' prio=50 status=active
`- 7:0:0:1 sdd 8:48 active ready running
3600a098000fd58fa000000205d0274da dm-6 LENOVO,Universal Xport
size=20M features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=1 status=active
`- 7:0:0:7 sde 8:64 active ready running

I don't know if the problem is with new linux kernel, or some new libraries, beacuse multipath is more related to linux than Proxmox itself

I will finish the configuration to test multipath with Proxmox 5.4
I will not test Proxmox 6 until i know if is stable to use in production.
 
multipath-tools or the upstream version changed a lot and some stuff is different now. All discussed in Debian Bug #932307

This worked for me - default section was changed from Debian Stretch to Debian Buster (PVE5 -> PVE6):

Code:
root@pve ~ > cat /etc/multipath.conf
defaults {
    find_multipaths no
}

blacklist {
     devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
     devnode "^hd[a-z][[0-9]*]"
     devnode "^sda[[0-9]*]"
     devnode "^cciss!c[0-9]d[0-9]*"
}

multipaths {
    multipath {
        wwid    1FreeBSD_iSCSI_DISK_10000001
        alias   asm_iscsi
    }
}

root@pve ~ > multipath -ll
asm_iscsi (1FreeBSD_iSCSI_DISK_10000001) dm-5 FreeBSD,iSCSI DISK
size=128G features='0' hwhandler='0' wp=rw
|-+- policy='service-time 0' prio=1 status=active
| `- 3:0:0:0 sdb 8:16 active ready running
`-+- policy='service-time 0' prio=1 status=enabled
  `- 4:0:0:0 sdc 8:32 active ready running
 
Autoreply, in my case i have well configured:

- multipath-tools installed, service active and running
- /etc/multipath.conf well configured for HPE 3PAR
- 4 HBA path detected by rescan-scsi-bus.sh
- restarting multipath-tools.service
- multipath -ll haven't result
- multipath -v3 respond "sdb orphan path, only one path"
- not /dev/mapper mpath0 device

A lot of test and config tested, however the solutions was;
# sudo multipath -a "uuid asigned to multipath"
# sudo systemctl restart multipath-tools.service

Then the mpath0 device was created and mount the HPE 3PAR in the HA Cluster.
 
Same for me, if removed the path_selector "round-robin 0" and it work also with find_multipaths yes. Seems than the only way to work with round robin is to say no to find_multipaths.

is it normal than, also if in round-robin, the "multipath -ll" command still indicate for one device status=active and for the other status=enabled?
 
Last edited:
is it normal than, also if in round-robin, the "multipath -ll" command still indicate for one device status=active and for the other status=enabled?

That depends on the server presenting the luns. If your server is capable of ALUA and it is enabled, those two groups should merge into one.
 
I'm trying to figure out how to proper activate and configure in IBM Storewize v7000. It's ALUA compliant, let see...
 

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