Dear Keith
Looking at the info you provided, I'm not familiar enough to know if you are trying to use NPIV (vFC) to connect IBM i to PureStorage. But if this is the case, did you ever ask PureStorage whether or not NPIV connection to IBM i is supported (by PureStorage emulating certain SAN disk type that IBM i supports)? And if so, what needs to be done in PureStorage's and VIOS's configuration to enable NPIV connection?
In case you will ask and the answer is not supported or they have no idea, another choice you can try is to create VIOS's virtual disk from PureStorage and see if IBM i would be able to see the vDisk units from VIOS or not. I see that this is a better bet for you as it was successfully used before with XIV Storage (if you recognize this defunct SAN product) that IBM i cannot connect to with NPIV.
Keep in mind that IBM i likes a lot of disk units so you do not use vDisk/LUN units size that is too large. If PureStorage uses SSD/NVMe, then I would use a rule of thumb that each IBM i core needs at least 8 disk units - a few more are even better if you know your workload is disk IO intensive at its peak.
If vDisk from VIOS works for you (I'm fairly certain it would), makre sure you allocate sufficient CPU and memory to VIOS as it determines the quality and consistentcy of vDisk/NPIV response time. I had a recent case where VIOS (providing NPIV from FS5K to IBM i) was allocated 0.1 CPU with Uncapped capability to 1 full CPU from a Shared Processor Pool of 2 cores that 3 other IBM i LPARs also share. This was a BAD design as it caused disk response to degrade badly when disk workload (IOPS and/or MB/sec.) increased by only a moderate degree. The degrade went from 0.4 msec. at low disk IO workload to 10-15 msec. when the the total disk IO workload from 3 IBM i LPARs increased only moderately and it caused the night batch jobs to take too long to run. Use PDI chart named Disk Throughput Overview for Disk Pool to check on this. You can also use VIOS Performance Advisor tool but last I heard this had a problem in viewing the report.
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Education is not the learning of facts but the training of the mind to think. -- Albert Einstein.
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Satid S.
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Original Message:
Sent: Wed July 19, 2023 03:11 PM
From: Keith Barth
Subject: IBM i Install on Pure Storage
I am working with a colleague on a proof of concept to install an IBM i instance on a Power 9 frame using Pure Storage. To this point we have the storage allocated and we are showing that the virtual adapters on the VIO servers are logged in to the storage. Unfortunately when we go to do the install, we are not seeing the storage listed and cannot proceed. Here is what we are seeing on the VIO servers when we run the lsmap -all -npiv command:
VIOA
Name Physloc ClntID ClntName ClntOS
------------- ---------------------------------- ------ -------------- -------
vfchost2 U9009.42A.786B240-V1-C5 3 REC01 IBM i
Status:LOGGED_IN
FC name:fcs0 FC loc code:U78D2.001.WZS0D8R-P1-C4-T1
Ports logged in:3
Flags:0x32a<LOGGED_IN,STRIP_MERGE,SCSI_CLIENT>
VFC client name:DC02 VFC client DRC:U9009.42A.786B240-V3-C4
VIOB
Name Physloc ClntID ClntName ClntOS
------------- ---------------------------------- ------ -------------- -------
vfchost2 U9009.42A.786B240-V2-C7 3 REC01 IBM i
Status:LOGGED_IN
FC name:fcs3 FC loc code:U78D2.001.WZS0D8R-P1-C9-T2
Ports logged in:3
Flags:0x32a<LOGGED_IN,STRIP_MERGE,SCSI_CLIENT>
VFC client name:DC01 VFC client DRC:U9009.42A.786B240-V3-C3
I was wondering if anyone else had attempted installing IBM i using Pure storage and could possibly assist us with seeing the storage.
Thanks,
Keith Barth
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Keith Barth
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