VMFS Datastore missing

After successfully install of ESXi 3.5 server, my datastore1 disappeared unexpectedly after first or second reboot. Is possible to be because of my “hacks” in “Advanced Settings”, but I’m not very sure about that. Looking in /var/log/messages I spotted some very strange errors:

Error Stream from partedUtil while getting partitions: Error: The partition table on /dev/disks/vmhba0:0:0:0 is inconsistent. There are many reasons why this might be the case. However, the most likely reason is that Linux detected the BIOS geometry for /dev/disks/vmhba0:0:0:0 incorrectly. GNU Parted suspects the real geometry should be 953869/64/32 (not 121601/255/63). You should check with your BIOS first, as this may not be correct. You can inform Linux by adding the parameter disks/vmhba0:0:0:0=953869,64,32 to the command line. See the LILO or GRUB documentation for more information. If you think Parted’s suggested geometry is correct, you may select Ignore to continue (and fix Linux later). Otherwise, select Cancel (and fix Linux and/or the BIOS now). Geometry Known: 0

Seeing that, I tried to rescan all the partitions of the my disks with

vmkfstools -V


Running this command I get another error/warning

Oct 22 09:21:14 vmkernel: 0:00:00:24.772 cpu7:1220)LVM: 5579: Device vmhba0:0:0:3 detected to be a snapshot:
Oct 22 09:21:14 vmkernel: 0:00:00:24.772 cpu7:1220)LVM: 5586: queried disk ID:
Oct 22 09:21:14 vmkernel: 0:00:00:24.772 cpu7:1220)LVM: 5593: on-disk disk ID:
Oct 22 09:21:14 vmkernel: 0:00:00:24.772 cpu7:1220)ALERT: LVM: 4482: vmhba0:0:0:3 may be snapshot: disabling access. See resignaturing section in SAN config guide.

About “resignaturing” I found a good article in Vmware Knowledge Base http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=9453805 which solved my problem.

You should enable resignaturing on ESX host:
1. Log with VIC Client
2. Click on ESX Host and go to Configuration -> Advanced Settings -> LVM
3. Set the value of LVM.EnableResignaturing to 1
4. Click ok (save)
5. go to Configuration -> Storage Addapter and press Rescan Adapters
6. Now you should see your old “missing volume” appearing with a name starting with “snap-”
7.Click on ESX Host and go to Configuration -> Advanced Settings -> LVM
8. Set the value of LVM.EnableResignaturing to 0
9. Click ok (save)
10. Now you should rename your datatstore with the old name and you are done.

Now both errors disappeared from my message file, and my datastore is back.

Good Luck!