NVMe drives have a "namespace" which sets the block size. The default
block size is 4k, which can only be added to VG's with other 4k disks.
https://www.ibm.com/docs/en/power9?topic=device-creating-namespace-nvmeThere was a discussion on the community forums previously about this.
Here's an example of different NVMe drives with different namespaces.
# lsdev -c disk
hdisk0 Available 00-00 NVMe 4K Flash Disk
hdisk1 Available 03-00 NVMe 4K Flash Disk
hdisk2 Available 00-00 NVMe Flash Disk
hdisk3 Available 03-00 NVMe Flash Disk
In Diag you can remove the namespace and create a new one like you
handle pdisks vs hdisks.
At replacement time, you should rmdev the hdisk and the NVMe parent,
or use diag's replacement procedure to do it for you.
The CE must use the HMC FRU replacement procedure. That safely powers
down the NVMe slot and prompts them through the steps to hot replace
it. NVMe is more like a PCI slot than a SCSI drive slot. I prefer to
use the procedure rather than rely on hot swapping.
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Russell Adams
Russell.Adams@AdamsSystems.nlPrincipal Consultant Adams Systems Consultancy
https://adamssystems.nl/
Original Message:
Sent: 11/17/2023 10:12:00 AM
From: Robert Berendt
Subject: RE: Replacing NVMe drives hosted by VIOS
I'm with Mackey on this.
Also, I question "Don't hotswap, insist the CE use the HMC replacement procedure." as I get the impression that IBM was really insistent on that link that the CE is going to do nothing but pull the old drive out and put the new one in.
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Robert Berendt IBMChampion
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Original Message:
Sent: Thu November 16, 2023 12:33 PM
From: Russell Adams
Subject: Replacing NVMe drives hosted by VIOS
On Thu, Nov 16, 2023 at 05:23:48PM +0000, Robert Berendt via IBM TechXchange Community wrote:
> Not that I have needed to replace any NVMe's yet but I like to know how before it happens.
Robert,
It's much the same. You'll still remove the NVMe in diag. Don't
hotswap, insist the CE use the HMC replacement procedure.
When the new disk is there, make sure you recreate the namespace on
the NVMe to match the blocksize of your other disks.
Thanks.
------------------------------------------------------------------
Russell Adams Russell.Adams@AdamsSystems.nl
Principal Consultant Adams Systems Consultancy
https://adamssystems.nl/
Original Message:
Sent: 11/16/2023 12:24:00 PM
From: Robert Berendt
Subject: Replacing NVMe drives hosted by VIOS
Not that I have needed to replace any NVMe's yet but I like to know how before it happens.
I found this article for SSD's or SAS but I'm wondering if there's a difference when doing NVMe. Especially since it clearly states:
"Note: It is a customer responsibility to perform these tasks, when an IBM service representative is replacing the disk unit then they are only responsible for the physical replacement of the disk unit."
https://www.ibm.com/support/pages/node/6616709?myns=pwrmicro&mynp=OCTI0005E&mynp=OCTI000B2&mynp=OCTI0005G&mynp=OCTI000B1&mynp=OCTI0005F&mynp=OCTI000B3&mync=E&cm_sp=pwrmicro-_-OCTI0005E-OCTI000B2-OCTI0005G-OCTI000B1-OCTI0005F-OCTI000B3-_-E
And I believe that they just be right about the customer responsibility since all of the CE's that were dispatched to me to replace VIOS drives didn't know what VIOS was and tried to use IBM i commands.
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Robert Berendt IBMChampion
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