DISKS: which local and which remote? 2

[7280]

Hi,
I have two servers with aix 5.3 in cluster. These systems are attached to a SAN (EMC Symmetrix).
On these systems some vg are clustered while others no.
What I want to know if a specific vg (not clustered) is on internal disks or on SAN. How can I know this.
lspv shows same identical names.
lspv output is:
hdisk1 00c548dc8e7afdaa rootvg active
hdisk0 00c7632fcb5c2092 rootvg active
hdisk2 none None
hdisk3 00c7632f087bae73 diskhbVG
hdisk4 00c7632f087d2539 oraVG
hdisk5 00c7632f55296913 backupvg active
hdisk6 00c548dc8eee08d2 None
hdisk7 00c548dc08fbf2f2 docreposVG active
hdisk8 00c7632f12ffd68b None

So I want to know if backupvg is on internal or not.

Thanks.

 

[p5wizard]

comparing "lspv" output with "lscfg|grep hdisk" or "lsdev -Ccdisk" output should get you along...

HTH,

p5wizard

 

[khalidaaa]

The way i do it is this:

# lspv
hdisk0          00c5c1ebd9979ea1                    rootvg          active
hdisk1          00c5c1eb216d1505                    rootvg          active
hdisk2          00c5c1eb19eacaaf                    imagevg         active
hdisk3          00c5c1eb19eacbcd                    imagevg         active

Then i take for example hdisk0 and do this

# lsdev -C -F parent -l hdisk0
scsi0

# lsdev -C -F parent -l hdisk2
dar0

so the one with scsi, i know its internal but the one with dar, it should be from SAN.

Regards,
Khalid

 

[7280]

Hi,
lscfg | grep hdisk is very clear.
lscfg|grep hdisk
* hdisk2 U7311.D20.650EB8B-P1-C07-T1-W5006048C4A857D5F-L0 EMC Symmetrix FCP MPIO Raid1
* hdisk3 U7311.D20.650EB8B-P1-C07-T1-W5006048C4A857D5F-LA000000000000 EMC Symmetrix FCP MPIO RaidS
* hdisk4 U7311.D20.650EB8B-P1-C07-T1-W5006048C4A857D5F-L15000000000000 EMC Symmetrix FCP MPIO RaidS
* hdisk7 U7311.D20.650EB8B-P1-C07-T1-W5006048C4A857D5F-L12000000000000 EMC Symmetrix FCP MPIO RaidS
* hdisk8 U7311.D20.650EB8B-P1-C07-T1-W5006048C4A857D5F-L13000000000000 EMC Symmetrix FCP MPIO RaidS
+ hdisk5 U7311.D20.650EB8B-P1-C08-T1-L8-L0 16 Bit LVD SCSI Disk Drive (73400 MB)
+ hdisk6 U7311.D20.650EB8B-P1-C08-T2-L8-L0 16 Bit LVD SCSI Disk Drive (73400 MB)
+ hdisk0 U7879.001.DQD3C7P-P1-T14-L4-L0 16 Bit LVD SCSI Disk Drive (73400 MB)
+ hdisk1 U7879.001.DQD3C7P-P1-T14-L5-L0 16 Bit LVD SCSI Disk Drive (73400 MB)

Also lsdev -Ccdisk is usefull.

lsdev -C -F parent -l diskname gives a less clear output; in my case scsi for internal disks and fscsi for emc disks (fibre channel).
So from this output it seems that hdisk6 is not assigned to any vg, so I can use it, right?
I'd like to assign it to backupvg.

Thanks again.

 

[p5wizard]

...unless the disks which show up as "None" on this server are in use on the other server of the cluster...


HTH,

p5wizard

 

[khalidaaa]

Yeah p5wizard is right! but i guess even if he tries to use it and it is already being used by the other node in the cluster, it will not let him to do so because the disk will be somehow locked by the other node!

I don't know never tried it but just follow what p5 said and you will be ok

Regards,
Khalid

 

[7280]

No the disk isn't assigned to the cluster because it's local.
I also ran lspv -l hdisk6
0516-320 : Physical volume 00c548dc8eee08d20000000000000000 is not assigned to
a volume group.

Thanks again.

 

[7280]

Last thing sorry. I know it should be another post but it's very fast.

By assigning a new PV to an existing VG, existing data will not be deleted?
This VG has one PV and I want to assign a new PV. But I don't want to loose the existing lv/fs.

I'm using smitty vg, then Add Physical volume.
Is this correct?

 

[khalidaaa]

Then it seems to be ok Go ahead bro

 

[p5wizard]

Well, just because it's a SCSI disk, that doesn't mean it can't be shared by two servers (Some SCSI backplanes allow dual host connections). But I assume you know how the SCSI disks are connected and to which host (or hosts).

So yes, go ahead. - The "None" disks seem to have been a member of one of your VGs at one point though (PVID is not "none")...

Adding a disk to a VG (extendvg) only adds free space to that VG, doesn't (shouldn't) do anything to the LVs/FSs already in the VG.



HTH,

p5wizard

 

[7280]

Thanks p5 for the explanation about scsi. I inherited this system so I'm not really sure about the configuration.
But I think that this disk is not shared because the shared disks reside on EMC.
Also I don't see this disk on the other node.

But now it seems not assigned to any vg (lspv -l hdisk6).
It's interesting the observation about pvid not "none". I don't know where this was assigned.

I'll try to add the disk add let you know.
Thanks again.

 

[7280]

hmm.. it failed:
Command: failed stdout: yes stderr: no

Before command completion, additional instructions may appear below.

0516-1398 /usr/sbin/extendvg: The physical volume hdisk6, appears to belong to
another volume group. Use the force option to add this physical volume
to a volume group.
0516-792 /usr/sbin/extendvg: Unable to extend volume group.

How can I know if it's really assigned or not to a vg?

 

[p5wizard]

Try to read the VGDA on the disk and see if that gives you a clue?

readvgda /dev/hdisk6|more

You should see a.o. the names of the LVs and their partition map. It lists the PVs and LVs that were in the VG this disk once belonged to at the time the disk was in that VG.


HTH,

p5wizard

 

[khalidaaa]

Nice command p5wizard Its my first time to know about it.

7280, i don't know if this comment would help but i can see that your disk has already got a PVID! which i guess it was used somehow or just assigned a PVID manually.

I suggest you go through the nice command provided by p5wizard and if you are sure that nothing in that disk then you can easily go ahead with the force option!

extendvg -f backupvg hdisk6

Regards,
Khalid

 

[7280]

Thanks p5!
I already assigned the disk, but for the future it will be very usefull.

I checked and the disk wasn't in use. I think it was used during installation for some testing purposes. After I put this disk in the vg I didn't recieve errors, so it was really not used

Thanks again!