[kwlug-disc] NVME failure?

[Khalid Baheyeldin]

Short version: what is the longevity of NVME disks under heavy writes,
e.g. for MySQL database?

I am hoping that some hardware knowledgeable folk would clue me in on
this hardware related issue.

Basically, I had a client who got a new server over a year ago. The
hosting company, a large US based host, recommended that we use an
NVME disk for MySQL. This is a plain old physical server running
Ubuntu Server 20.04 LTS (no VMs, no docker). It has 64GB RAM and 16
cores. The root file system is two SSDs that are software RAIDed
together. 1

We had kernel patches accumulating over that year, and I wanted to do
a reboot to make sure that everything started normally. Upon rebooting

[  128.001364] nvme nvme0: Device not ready; aborting initialisation
[  128.002041] nvme nvme0: Removing after probe failure status: -19

That NVME was a 1.6TB Micron 9200 MAX, if that matters.

There was no device file under /dev/ for that disk anymore.

After the host replacing the NVME, everything was normal, as below:
[    7.558183] nvme nvme0: Shutdown timeout set to 10 seconds
[    7.562576] nvme nvme0: 32/0/0 default/read/poll queues
[    7.565741]  nvme0n1: p1
...
Jul 31 15:27:54 live multipath: nvme0n1: failed to get udev uid:
Invalid argument
Jul 31 15:27:54 live multipath: nvme0n1: uid =
eui.000000000000000100a0750128df8715 (sysfs)
...
[    6.008941] nvme nvme0: pci function 0000:b6:00.0

[   11.571864] EXT4-fs (nvme0n1p1): mounted filesystem with ordered
data mode. Opts: (null)

Now to the questions:

- Why would a device be functional before a reboot but totally go away
after, and not being even detected by the operating system?
- Are NVME as unreliable as SSDs or better? Or are they just faster?

All thoughts appreciated ...
--
Khalid M. Baheyeldin
2bits.com, Inc.
Fast Reliable Drupal
Drupal performance optimization, hosting and consulting.
"Sooner or later, this combustible mixture of ignorance and power is
going to blow up in our faces." -- Dr. Carl Sagan