This is getting very confusing for me, and appreciate if someone can help.
Platform: Power VM ( Virtual I/O Server)
ioslevel 2.1.3.10-FP23
# oslevel -s
6100-05-00-0000
Storage: IBM DS4300
Two HBAs - Dual Port Fibre Adapter Channels
Each card has two ports , so a total of 4 ports going through two San Switches into one SAN box
However, the SDDPCM fileset might be required on a VIOS partition for attached DS8000 and/or SVC devices and you might want to attach also DS4000/DS5000 devices to the same VIOS. A supported configuration with SDDPCM on VIOS2.1 for DS8000 and/or SVC devices and native AIX MPIO for DS4k/DS5k devices might be achived by using SDDPCM 2.5.1.0 on VIOS 2.1.2.10-FP-22.1 (or higher) and manually deselecting the SDDPCM driver option for the DS4k/DS5k devics with the manage_disk_drivers command. Such a configuration would be based on:
VIOS 2.1.2.10-FP-22.1 (or higher) required by SDDPCM 2.5.1.0 and including the new manage_disk_drivers command
SDDPCM 2.5.1.0 (or higher) fileset with appropriate SDDPCM prerequisites (e.g. devices.fcp.disk.ibm.mpio.rte, V1.0.0.20)
selecting AIX_APPCM as present driver for attached DS5k/DS4k subsystems with manage_disk_drivers command (i.e. deselect AIX_SDDAPPCM)
AIX MPIO using SDDPCM for DS8000 / SVC devices (i.e. only the DS8000/SVC devices are managed by SDDPCM)
AIX MPIO using native AIX PCM for all DS4k/DS5k devices (i.e. all DS4k/DS5k devices are managed by the default AIX MPIO driver with the native AIX PCM)
How can I solve this issue of Same Disk appearing Twice (see hdisk8 and hdisk9 have the same PVIDs)
How should I proceed ?
---------- Post updated 05-07-16 at 12:35 PM ---------- Previous update was 05-06-16 at 01:06 PM ----------
After a little more study, I have come to known that it is important to have the right zoning, on this forum, I have read
Quote:
In your case, if your AIX system sees extra "dacX" devices or extra "hdiskX" devices, there's an error in your config & you'll need to go back & debug your installation.
I have 2 x Dual Port HBA
HBA 1
FCS0
FCS1
HBA 2
FCS2
FCS3
What is the best zoning practice ?
fcs0 (HBA 1) -----> switch A <------ controller A
fcs3 (HBA 2) -----> switch B <------ controller B
or could i make it like this
fcs0 (HBA 1) -----> switch A <------ controller A
fcs1 (HBA 1) -----> switch B <------ controller B
fcs3 (HBA 2) -----> switch B <------ controller B
fcs4 (HBA 2) -----> switch A <------ controller A
It has nothing to do with how many ports one adapter has. A "path" is just a way of looking at one disk. The short answer is, a "path" is a certain connection from the system to the disk, using a specific way.
Here is the long version: consider the following setup. You have one FC-Adapter (two ports, FCa, FCb), which is connected to two FC-switches (SWa, SWb), which both connect to a storage system. The switches are themselves connected via a crossover-link. You create a single disk on this storage system. This disk will be seen over different paths: FCa-SWa-Disk, FCa-SWa-SWb-Disk, FCb-SWb-Disk, FCb-SWb-SWa-Disk. AIX will therefore create 4 different hdisk-devices when you run cfgmgr.
Now, this is not very comfortable, especially when you create several disks. Each disk will be seen via 4 paths (if you have a fabric more complex than the one i sketched above you might have even more paths) and soon you will have trouble to remember that hdisk137 is in fact hdisk49 and also hdisk87 and hdisk3.
This is where MPIO comes into play: it takes all the hdisk-devices which represent in fact one and only one disk (its like taking a picture of a building from several angles - regardless of how many pictures you take it is always the same one building) and builds a "super-device" above them. You can use this super-device to build VGs, LVs and all other sorts of things you use normally disks for. The MPIO (Multipath-I/O) driver will take care about the relationship of the different hdisk devices and do the bookkeeping for you (and the OS as well).
And there is an additional advantage to it: suppose Switch A in the above picture would fail. Two of the four hdisks (the two paths involving SWa) would be inaccessible, because these pathes would not be usable, but the super-device still works, because it uses ALL paths and if two fail there are still two more to use. In fact this is the main reason one builds such complex fabrics with parallel FC-switches, crossover-links and the like.
Volume groups other than rootvg normally use virtual SAN disks called vpaths.
The system-side SAN attachment is done through 2 Fibre Channel PCI adapters, connected to 2 independent SAN fabrics. The logical disks on the SAN are attached to each fabric via 2 storage paths, totaling to 4 paths from the host to each LUN.
Each path to a LUN is seen by AIX as a fiber channel disk device
The Subsystem Device Driver (SDD) groups all paths to the same LUN into a multipath virtual device (vpath) which is accessible for IO operations [MPIO] as long as at least one of the component paths is available.
My only concern is not to see the HdiskX as double, with same PVID? any idea folks ?
Last edited by filosophizer; 05-10-2016 at 06:04 AM..
I just installed IBMsddsun64_........... on my sun server. I untarred it (tar xvf) & I tried to install the paxkage. When I did pkgadd -d ./IBMsdd..... I get a message Error, no packages were found.
Any idea
Thanks, (1 Reply)
Hi all,
Sorry if this is in the wrong place but needed to make sure lots of people saw this so that hopefully someone will be able to help.
Basically i've upgraded a test server from 4.3 to 5.3 TL04.
The server has hdisk0 and 1 as rootvg locally but then has another vg setup on our ESS... (1 Reply)
Hello Unix Admins:
Has any one in this distribution list implemented SVC (SAN Volume Contoller - A solution from IBM) in your environment? If you have, do you have any do's / don'ts? Anything which you like sharing would be really appreciated.
For example, my inputs:
I tried implementing... (1 Reply)
Can anyone recommend me some reading material surrounding how AIX handles LUNs:
- with and without MPIO installed
- with and without SDD or SDDPCM installed
Where does lspath sit in all of this (MPIO layer?). Can a system be built with just MPIO software? Is MPIO software even needed?
I guess... (0 Replies)
I was wondering if there is a way of auto-detecting a new vpath, using IBM's SDD driver, on a Linux platform.
ON AIX it is a simple as running cfgmgr.
Alan (0 Replies)
Hi folks.
We want to move a "physical" AIX box to a VIOed LPAR. The physical box is running SDD with disks from a DS8300. I want to be able to reattach those LUNs from the DS8300 to my VIO server which is running SDDPCM and then assigned them back to my AIX LPAR. Any thoughts about this?
I... (1 Reply)
I have sdd driver installed correctly but
when I run the command:
datapath query adapter
No device file found
what does it mean.. it is not using vpath or whats wrong? (2 Replies)
We have AIX 6.1 system attached to SAN disks (DS4700 and DS8100) thru SVC.
Initially when the system was I forgot to install sddpcm drivers. and wanted to know how can i go with the installation of the sddpcm drivers.
My understandin going thru the manual ... (3 Replies)
I have same lun (hdisk3) assigned to 2 vios server (dual vio server) and this is mapped to the client lpar. I have sddpcm on the VIO.
On the VIOA, the attributes for fscsi1 and fscsi3 are set to fast_fail and dyntrk is set to yes
Now, if I do a lqueryvg -Atp on the hdisk3, I get a "DISK... (4 Replies)
hi all
we recently upgraded our san switches. after that, i found i got many hdisks showing in lsdev with status "Defined" and "Available". the number of "Defined" is equal to "Available". the time stamp shows all "Available" disks created at our downtime night.
"datapath query device"... (0 Replies)
05-07-2016