representing an existing lun to server

[ilayy]

hi all
i have an eva 5000 connected to linux redhat server where there is 2 luns presented to the server the first one is 1TB and the second one is 2TB
i have had a power failure after the power is back the server see only one lun of 1TB
i am thinking to unpresent the second lun and present it again to the server does that present any risk as there is a critical data on that lun?
after representing the lun to the server do i have to format it again to be a system file? or everything will be ok?

[Johan Guldmyr]

Hi!

Have you tried to just do a rescan on the linux-machine?
In Command View - what is the status of the vdisk that the server cannot see?

If server still does not see it after a rescan and the status of the vdisk is good in CV. Then maybe a restart of the server would be worth a shot before trying the unpresent/present option. You should not have to reformat/recreate file system, because then data would be gone right?

What about a clone - do you have business copy license? That might be worth a shot as well, make a clone and then present that to the same or another server..

[ilayy]

i did all of that and nothing is working
what i need to do is umpresent/present.
my question is
when i do unpresent and present again will the server ask to format the lun again as filesystem? or no

[Johan Guldmyr · Accepted solution]

If the LUN is in a good state then no, the linux-machine should reformat the LUN.

[ilayy]

sorry
but the answer was not clear you told me if it is in good state no. the os should format the lun again

can you clarify the answer please you mean if it is in good state it will not format it?

[John Liversidge]

Ilayy,
If the lun is good Linux will recognise it and not reformat.

[Maersk_Sto_Team]

Hi ilayy

Any OS recognizes a disk by the metadata it wrote on the disk.If for some reason this metadata is corrupt then unpresenting & representing the drive won't work. U may need to restore the data from a valid backup (Businass copy or tape or any other means).In case if you have the FS structure backup of the disk then that may be restored and tried.

Good Luck

[Johan Guldmyr]

ilayy - you can then check in command view what the state is of the lun/vdisk. When you mount it maybe run a fsck?

[ilayy]

i have just unpresent the lun and present it again because the lun was in good state