CentOS - Jan 2018 - systemd-udevd not applying ATTR to block device at boot

I suppose it would help if I posted relevant version info (sorry about that...)

CentOS Linux release 7.4.1708 (Core) @ 3.10.0-693.11.6.el7.x86_64
systemd-219-42.el7_4.4.x86_64

$ modinfo virtio_scsi
filename:      
/lib/modules/3.10.0-693.11.6.el7.x86_64/kernel/drivers/scsi/virtio_scsi.ko.xz
license:        GPL
description:    Virtio SCSI HBA driver
rhelversion:    7.4
srcversion:     A80DAE9007C7FCF3DDD1501
alias:          virtio:d00000008v*
depends:        virtio,virtio_ring
intree:         Y
vermagic:       3.10.0-693.11.6.el7.x86_64 SMP mod_unload modversions 
signer:         CentOS Linux kernel signing key
sig_key:        2C:BC:98:70:54:63:43:CA:3A:E1:20:C2:BC:EB:98:44:01:95:59:62
sig_hashalgo:   sha256

I'm happy to provide any other relevant info if needed! Thanks again!

Nick

?On 1/31/18, 12:49 AM, "CentOS on behalf of Nick.Jacques"
<centos-bounces at centos.org on behalf of Nick.Jacques at target.com>
wrote:

    Hi everyone,
    
    I have a udev rule file that contains a singular rule:
    
    SUBSYSTEM=="block", ACTION=="add|change",
ENV{ID_VENDOR}=="*Google*", ENV{DEVTYPE}=="disk",
ATTR{queue/scheduler}:="noop"
    
    When I use a Google Cloud instance and boot it, things work as expected and
/dev/sda (a persistent disk) uses the noop scheduler. If the instance also has a
Local SSD type disk, however, the change in scheduler is not applied. This is a
bit academic, because the Local SSD device uses noop by default (somehow, I
don?t see any udev rules for setting this outside of my own). But, for instance,
if I set the scheduler in the udev rules to ?cfq,? at boot, /dev/sda will use
cfq and /dev/sdb will use noop.
    
    If I run udevadm trigger after boot, then /dev/sdb will use cfq. So, it
appears that at boot time, for some reason, my scheduler is not being applied to
/dev/sdb.
    
    I?ve tried a handful of things:
    
    - changing the order of my udev rule file: I?ve tried 10-, 90-, and 99-
prefixes. My rule file is in /etc/udev/rules.d/.
    - using ATTR{queue/scheduler}:="noop" and
ATTR{queue/scheduler}="noop" (both the = and := operator)
    - searching the internet for all kinds of variations on ?udev rule not
applying at boot?
    
    but so far, I?ve come up empty-handed. The only thing I can think of is that
I am hitting some sort of race condition and udev is unable to set the ATTR in
/sys, but I?m not sure how I can confirm this.
    
    Below are dumps from udevadm of the block devices, /dev/sda (a Google Cloud
persistent disk that is my root partition) and /dev/sdb (a Google Cloud
ephemeral disk [local SSD] that is mounted at /local-ssd).
    
    Thanks in advance for any assistance!
    
    Nick
    
< trimmed udevadm output>