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SSO: celerra ndmp scsi_reserve question

Created: 15 Dec 2010 | 3 comments
X S's picture

we have a few celerra data movers that are sharing 8 tape drives in a NB v7 environment. by default, it appears that the celerra's ndmp is configured scsireserve=1 to reserve the tape drive. also by default, spc-2 reserve is enabled on the master server. we are being told that we should change the data mover to not use scsi-reserve if it is sharing tape drives. does anyone know if this is correct? we are seeing i/o open errors on the master server's event log and am wondering if the reserve config has anything to do with it. thanks in advance for your help.

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VirtualED's picture

I am in no way 100% sure on this, but it seems to me that NBU should be responsible for requesting/releasing SCSI reservation.  So if the Filer is locking these decides, then that will cause a problem for NBU or anything else trying to use those devices.

EMC in the past has always requested:

Server_param server_x -facility NDMP -modify scsiReserve -value 0

If they have changed there minds on this, then it should be because they made a change in the DartOS and your Tape Devices/Hardware support a new SCSI reservation format(SPC-3).

brandonn's picture

I currently have scsiReserve set to 1, though these are shared drives, I get no errors. I don't expect you should see these errors since NBU should grant resources appropriately to requesting hosts.

X S's picture

thank you both.  we're having trouble getting a straight answer from EMC right now.  we're trying to figure out if the scsireserve reserves only during the backup and then releases or if it just sets it to reserve once the device is created on the filer.  

i agree with the point virtualed makes that wouldn't it make sense that only one can be made responsible for the reservation?