StorNext labels overwritten - postmortem

Robert Leong -

Hello Robert,

Per our recent phone conversation, here is a collection of information regarding cvlabels.

You had asked if there was any way to determine what machine may have overwritten a cvlabel, I found this interesting tidbit in the man page on cvlabel that shows that there is hope in determining that machine....

 -g     When used in conjunction with the -l or -L options, the -g option also prints GUID information for EFI-labeled disks.  The GUID includes a timestamp and the MAC address of the node that created the label.

Use the -g option along with the -l or -L options to make your best attempt to do this.

 One common recommendation that we make to customers is that they should NOT zone in a new Windows machine on the fabric unless StorNext Client software has already been installed.  A very common and easy mistake for a logged in user to do is to answer "yes" to the question that is posed to allow Windows to take possession of new LUNs.  As for an official document or KB stating this, I have been un-able to locate anything that has been published, but you can use this email for an 'official statement'.


Hi Greg, thanks for the -g info, I will test it with our test SAN in our lab.  I would figure that the time-stamp and MAC info would be placed in the label during a legitimate cvlabel write, but I would guess if the labels were overwritten with something like a Windows formatted it would not have this info, but I will test it and find out, will let you know.



Test notes:

A LUN with correct StorNext label showing timestamp and MAC info: 

# cvlabel -gL | grep DH48

/dev/sdcc  [DotHill DH4824          G200] SNFS-EFI "lun_test1"  Controller '208000C0FF1BFD52', Serial '600C0FF0001EC26D3A1E675501000000', Sector Size 512, Sectors 585299935 (279.1GB), GUID b85094f4-057c-11e5-abcc-002590d372c0 [Thu May 28 14:01:33 2015 00:25:90:d3:72:c0]

The LUN was overwritten by dd (1st 100 Mbytes) = no timestamp and MAC info:

# dd of=/dev/sdcd if=/dev/zero bs=1048576 count=100
# cvlabel -gL | grep DH48
/dev/sdcc [DotHill DH4824 G200] unknown Controller '208000C0FF1BFD52', Serial '600C0FF0001EC26D3A1E675501000000', Sector Size 512, Sectors Max 585299935 (279.1GB)









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