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Re: HP-UX PV-LUN association

 
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Stuart Powell
Super Advisor

HP-UX PV-LUN association

I would like to know how I can associate the PV number on a HP-UX machine with a LUN created on an EVA4000. One of the suggestions that I heard was to create the LUN's one at a time controlling their introduction to a server. That only works when the server is available at the time the LUN's are created. In our case, we will be adding two new servers after all of the LUN's have been created for our production machines. It also does nothing for any future machine integrations into the SAN. I know that the process can be narrowed down by the LUN creation sequence and the hardware address seen in "ioscan", but there again that will not address all of the issues.
I would like to know if there is a way, either on each HP-UX server or on the EVA, to make a direct association between a specific LUN and the PV on the HP-UX host. I believe there is a similar lack of ability to make the association on the Windows servers as well.
I've also been told that Securepath is the ONLY option to attain this information. My understanding was that Securepath was need for load balancing and HBA failover. No sale support person informed me that I would not be able to intelligently manage the LUN's on the EVA without Securepath.
Does anyone have any input on this situation?
Sometimes the best answer is another question
12 REPLIES 12
Florian Heigl (new acc)
Honored Contributor

Re: HP-UX PV-LUN association

If You have *alot* of luck, the serial number of the disks could contain what You search for.

try diskinfo /dev/rdsk/cXtYdZ and hope it differs from a second EVA lun's output.

otherwise, it will be really hard, I'm currently facing a very similar problem while redistribution Clariion luns to their assigned controllers. :(
yesterday I stood at the edge. Today I'm one step ahead.
Bill Costigan
Honored Contributor

Re: HP-UX PV-LUN association

Very easy..

Look at the device name

/dev/dsk/c4t5d2

Take the number after the t (5) multiply by 8 and add the number following the d (2)

i.e, 5 * 8 + 2 = 42 this is LUN 42. all the disk device files with a t5d2 will be different paths to LUN 42.

e.g. c4t5d2, c10t5d2, c13t5d2 ....

Looking at the hardware path will show you which path it is for

e.g.

0/0/10/0/0.2.1.0.0.5.2

The first part 0/0/10/0/0 will match the hardware path of the fiber HBA.
the next 2 is the domain # of the switch and the next '1' is the port on that switch to which the eva controller is connected.

This example works for a brocade switch but the other vendor switches have similar numbers.
Stuart Powell
Super Advisor

Re: HP-UX PV-LUN association

Bill,

Great theory, but it doesn't hold up in my envirnment which consist of EMC labled Brocade switches connected to EMC 4700 Clariion arrays. On one host I have a device number of /dev/dsk/c9t0d5 which is LUN 26. On another host I have a device number of /dev/dsk/c9t0d5 which is LUN 21.
I was hoping that you had the answer. Thanks for the suggestion.

Stuart
Sometimes the best answer is another question
Stuart Powell
Super Advisor

Re: HP-UX PV-LUN association

Florian,

When I run diskinfo on the raw PV I do not get a S/N. Here's the output:
SCSI describe of /dev/rdsk/c9t0d5:
vendor: DGC
product id: C4700WDR5
type: direct access
size: 16384 Kbytes
bytes per sector: 512
rev level: HP03
blocks per disk: 32768
ISO version: 0
ECMA version: 0
ANSI version: 4
removable media: no
response format: 2
(Additional inquiry bytes: (32)31 (33)30 (34)20 (35)43 (36)4f (37)4e (38)54 (
39)52 (40)4f (41)4c (42)4c (43)45 (44)52 (45)20 (46)30 (47)30 (48)30 (49)20 (50)
20 (51)0 (52)0 (53)0 (54)3c (55)2 (56)60 (57)1 (58)9c (59)8 (60)c0 (61)13 (62)40
(63)0 (64)0 (65)0 (66)0 (67)0 (68)0 (69)0 (70)0 (71)0 (72)0 (73)0 (74)0 (75)0 (
76)0 (77)0 (78)0 (79)0 (80)0 (81)0 (82)0 (83)0 (84)0 (85)0 (86)0 (87)0 (88)0 (89
)0 (90)0 (91)1 (92)0 (93)2 (94)0 (95)46 (96)32 (97)30 (98)30 (99)31 (100)31 (101
)31 (102)30 (103)30 (104)36 (105)30 (106)36 (107)0 (108)6 (109)80 (110)ec (111)0
(112)c (113)20 (114)af (115)0 (116)0 (117)0 (118)0 (119)0 (120)0 (121)0 (122)0
)

Which is not much help at all.
On the Clariion's we have the LUN number and associated device file are displayed together in Navishpere Manager. If you are using Navisphere and can't find the information let me know and I'll try to help.

Stuart
Sometimes the best answer is another question
Florian Heigl (new acc)
Honored Contributor

Re: HP-UX PV-LUN association

Stuart - You wrote about EVAs, this is why I suggested checking for the serial and I even wrote what things look like with the clariion (they look bad).
the DGC luns apperently don't carry any usable information.
Next time ask the sales person for the manuals beforehand :)

I have yet to come up with a way to do this mapping.
navicli is no help as it will only show the clariion's view of things, and of course the clariion doesn't know the device paths hp-ux assigns to the luns.

If Your hosts are only attached to one FC4700, not two, this is solvable by using the HLU/ALU mappings quite easily because they're listed for each storagegroup separately.

Another thing I came up with but won't use in production environment is to use a host for documenting the mappings:
this host must be member of all storagegroups, thus seeing all disks.
with it, You get an ideal HLU/ALU mapping, and from this host You can use dd+ox to gather all PVIDs.
after that, restore the original SAN config, and re-colled the PVIDs from every lun each host sees.
the rest can even be done in excel.

About the intelligently managing:
Sorry, but You (and also the ppl here) should have thought of documenting this beforehand.
I don't talk about writing it down manually, but i.e. having a script binding luns via cli, assigning raidgroup and zoning and recording the changes in config data.
if You ask the sales people, they'll rather sell You some nice overpriced piece of java xml management framework. :)
yesterday I stood at the edge. Today I'm one step ahead.
generic_1
Respected Contributor

Re: HP-UX PV-LUN association

What is the wwn of the lun in according to your appliance for the diskinfo output you have given I am guessing that if you deciper the hex codes below you can find it in there :). I have 3 eva 5ks but its not presented to any of my HPUX machines. If you could post the diskinfo -v and the wwn out of the appliace of that lun and the lun number in the appliance I would be curious to see if I can decipher it. I do know if you look under windows in the registry you can see this wwn and the lun number winodws assigned so you can relate the booger back to a real disk. Windows and lun numbering is ugly.
Buy an XP next time LOL
Florian Heigl (new acc)
Honored Contributor

Re: HP-UX PV-LUN association

Did You try out any of the suggestions made?
yesterday I stood at the edge. Today I'm one step ahead.
Bill Costigan
Honored Contributor

Re: HP-UX PV-LUN association

Have you tried the command

powermt display dev=all

I've only used the CX not the FC arrays. The formula works for the CXs. At least it always did for me.

I guess it is possible that the FC can present a LUN (e.g. 21) to a host using any scsi address (e.g. 5). The eva does this and you have to check its configuration to see what LUN is being present as 5 so you can figure out which LUN is c9t0d5
Stuart Powell
Super Advisor

Re: HP-UX PV-LUN association

Florian,

Sorry for not updating the thread sooner. We have found a workable solution, though it is not simple.
When the SAN admin presents a LUN with Command View it will report back a LUN number. The admin notes that LUN number and the associated host and HBA address for the LUN number.
I'm not familar enough with Command View to say that you can control the LUN number but I think there is some flexibility. In my environment with two redundant SAN's and two HBA's on each server I also have to note the domain number for each switch. The LUN number is associated with each individual HBA.
When I do the ioscan and newfs I look at the hardware path and determin the LUN number for the HBA and which array to which it is attached. Then I fill in the spread sheet that connects the LUN number to the device number. As a final check I have been doing a diskinfo on the PV to make sure that the size matches the LUN created. Since I use PVlinks I also get confirmation when I run vgextend on the supspected alternate link and it shows up correctly in vgdisplay -v.
On the EMC systems do you have Navishpere Manager?

Bill,
Apparently powermt is a command for the XC systems. I don't have a man page on any of my systems.
But you are correct on the last statement.

Stuart
Sometimes the best answer is another question