Another iscsi/multipath question

Nov 10, 2020
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I "think" I have this configured correctly but wanted to see if there was others that might know better.

Step 1. in GUI add a new iscsi pointing to the iscsi portal and adding 1 target. (also uncheck Use LUNs)

Step 2. Add node-startup = automatic to /etc/iscsi/iscsid.conf (Restart iscsi service)
# systemctl restart iscsid.service

Step 3. Install multipath-tools and add multipath.conf and restart multipath services:
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]*"
wwid .*
}

blacklist_exceptions {
wwid "[wwid]"
wwid "[wwid]"
}

multipaths {
multipath {
wwid "[wwid]"
alias lun00
}
multipath {
wwid "[wwid]"
alias lun01
}
}

step 4. discover and log in to all paths from portal in step 1
# iscsiadm -m discovery -t st -p [portal ip]:3260 -l

Now if I check multipath -ll I see 8 paths which is whats expected. Is this the correct way?
 
Last edited:
Hi,

yes, this looks good.
But multipath setting highly depends on NAS configuration(Vendor specific).

Do you use LVM on this LUN, or do you create for every VM an extra LUN?
I would recommend you to use LVM.
 
@wolfgang I use LVM on the LUN since that is WAY easier :) and its also very similar to the ESXi setup using VMFS. Our SAN backend is emc VNXe and from my testing so far these settings work great after I figured out that the MTU on linux want set because I tried to set it to 9216. After setting that to 9000 on the pve side things started working better.

Next piece is to have Packer make templates and Terraform to deploy the hosts and I'm golden.