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Yattong
Expert
Expert

LUN scan doesnt show new luns until reboot?

hi

quick background, 16 esx 3.0.2 with eva 6000.

Whenever we create a new lun, or re-size a lun or what ever... we go through the correct procedures, i.e removing from datacentre / hosts and rescanning the lun.

The question is... sometimes the new LUN does not appear, no matter how many times I try to scan it, either through the VC or by command prompt. (esxcfg-rescan). It does appear however, after a reboot. No scanning needed after.

Is there something I can restart (not server reboot), so I can then do another scan for it to appear?

Ive tried rebooting the mgmt-vmware. Will try vxpa next.

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Yattong
Expert
Expert

vpxa doesnt do it either.

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Luis_F
Enthusiast
Enthusiast

Do you have class-c HP blades with 4 GB HBA mezzanines?

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Chamon
Commander
Commander

I have had

vmkfstools -s vmhba0

vmkfstools -s vmhba1

work for me when esxcfg-rescan did not.

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jschlach
Enthusiast
Enthusiast

for us, allocation new LUNs means changing the zoning on the array. it seems like the zoning is only read by the gear when HBA cards login to the switch. so to get new luns showing up, i first verify and save the config from our array manager software, then i unplug the host from the switch, plug it back in. at that point, a lun/vmfs rescan will work.

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Yattong
Expert
Expert

cool...

I'l give the vmkfstools command a go next time it happens and let you know.

We have HP DL585 and HP EVA6000 SAN.

I dont want to reboot / pull any cables out as this will make me have to vmotion off all the vm's hosted and is time consuming as we are averaging 40 sessions per host. (i know its a lot, but i have no say in it)

Thanks guys.

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Yattong
Expert
Expert

nope,

the vmkfstools -s command didnt help.

Any other ideas guys? Is it just me whos experiencing this?

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christianZ
Champion
Champion

Have you checked your /var/log/vmkernel file after unsuccessful rescanning.

Are your all luns ids unique?

Maybe posting of (from a few hosts)

esxcfg-mpath -l

could give more info here?

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jhanekom
Virtuoso
Virtuoso

I've also seen this and have found that, in most cases, rescanning through the VI Client rather than "vmkfstools -s ", solves it. (vmkfstools -s, in my case, allowed me to see the storage from the console but the VI Client didn't reflect the changes.)

Unfortunately I don't know what other commands the VI client issues at the back in addition to a normal rescan to ensure the new space becomes visible to itself.

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thickclouds
Enthusiast
Enthusiast

I always have to do 2 rescans from the gui. We are using a CX310.

Charlie Gautreaux vExpert http://www.thickclouds.com
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Yattong
Expert
Expert

sorry for the delay guys!

Just checked the vmkernel file and its seems as though the scanning is fine. No errors appear. It just stops short of LUN 43, currently up to LUN 42.

Attached is the esxcfg-mpath -l

Guys, ive scanned loads, 5 times + and guarenteed... it will show up on reboot.

Tried vmkfstools and esxcfg-rescan and viclient.

Comeee onn..... guru wannabe's! 10 points up for grabs still... hahaa

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Chamon
Commander
Commander

I know this sounds weird but have you restarted the VC server service on the VC and/or rebooted it?

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Yattong
Expert
Expert

No, well. it has been rebooted at some point in time but not as a remedy for this.

Is there something you're hoping will be reset by this, that I can restart on a specific host by command line?

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Chamon
Commander
Commander

I am not sure what it is doing but a friend said that has helped when they were having problems. However it was after the LUN had been formatted VMFS3 and one of the Host could see it after a rescan but the others did not. Even through the SC. So it wasn’t a problem of needing to restart the mgmt-vmware service on the host. They needed to restart the VC server service on the VC for the Hosts to see the LUN. I just thought that I would pass it on to you.

Just so I am sure about your situation. You are able to format the LUN through the VC server is this correct? Using the add storage wizard. Or are you doing it through the service console?

Then you try to do a rescan and the hosts don’t see anything. None of them correct. Not until a reboot right?

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Yattong
Expert
Expert

ok, yep Im able to add / format the datastore via VC wizard. Havent actually tried doing it through command line.

Most of the server are able to see the lun, the ones that cant, Ive done the above and yet the lun did not appear until reboot of these servers.

Bit of background, using a HP EVA6000 43 x 500GB LUNs going through 2 cisco fabrics onto 18 HP DL585's with 64GB ram.

Running 650 vms ramping up to 700+. (I know, I know, these servers are getting spanked... but what can I do? The ppl paying for this want moreeeee....!!!

Anyway, I have kept 4 out of the 18 servers available for this thread but will need to reboot them at the monthly patching date.

I'll give the VC a reboot and let you all know.

Thanks alot

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Chamon
Commander
Commander

Once you have formatted the LUN ‘add storage’ have you then gone to the other hosts and performed the rescans? They should see them at that point without a reboot.

To do it form the SC here are the steps. This will also align it correctly.

To align VMFS volumes, the alignment will be done at ESX server level using fdisk and at the VM level. This is because both the ESX Server and the clients will put MBRs on the LUNs. The ESX must align the VMFS volume, and the client systems must align their virtual disks.

To align the ESX server:

1. On service console, execute fdisk /dev/sd is the device on which you would like to create the VMFS.

2. Type "n" to create a new partition.

3. Type "p" to create a primary partition.

4. Type "1" to create partition #1.

5. Select the defaults to use the complete disk.

6. Type "x" to get into expert mode.

7. Type "b" to specify the starting block for partitions.

8. Type "1" to select partition #1.

9. Type "128" to make partition #1 to align on 64KB boundary.

10. Type "r" to return to the main menu.

11. Type "t" to change partition type.

12. Type "1" to select partition #1.

13. Type "fb" to set the type to fb (VMFS volume).

14. Type "w" to write label and the partition information to disk.

By declaring the partition type as fb, the ESX server will recognize the partition as an unformatted VMFS volume. You should be able to put a VMFS file system on it using the MUI or vmkfstools. Next, the virtual disks for each VM must be aligned. For Linux VMs follow the procedure listed above. For Windows VMs, use the procedure for Windows, above.

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jhanekom
Virtuoso
Virtuoso

Just pointing it out for the record: creating a VMFS volume from within the VI client will also align that volume. It is not necessary to create it from the SC in order for it to be aligned.

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Chamon
Commander
Commander

Right you are and I probably should have said that as well so thank you for pointing it out. I was just trying to provide them with additional info since they said that they were not sure how to do it from the SC.

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Yattong
Expert
Expert

hey,

no good, even on reboot of VC im afraid...

have tried re-scanning twice after reboot of VC and the 2 command lines above.

I think the reboot of ESX is coming up v.soon.

Oh well... =(

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aldin
Enthusiast
Enthusiast

which HBA do you use, have you try to upgrade firmware on it.

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