Is it possible to use persistent reservation with a direct lun in a RHEV guest system?
Issue
- Persistent Reservation “sg_persist” command fails when a disk is exposed to the Guest OS using RHEV-M 3.5.
- In RHEV-M, when creating a guest OS and exposing FC disks to it, by default source device is selected as mapper device like `/dev/mapper/..".
- Even when sg_io parameter is set to ‘Unfiltered’, persistence reservation command is failing.
From Web-admin portal >> External (direct lun) >> Interface: VirtIO-SCSI >> Storage Type: Fibre Channel >> Enable SCSI Pass-Through >> Allow Privileged SCSI I/O

- In the XML of the guest, this is seen as :
<disk type="block" device="lun" sgio="unfiltered" snapshot="no">
<driver name="qemu" type="raw" cache="none" error_policy="stop" io="native"></driver>
<source dev="/dev/mapper/3624a9370f112d7a4b4d4270600012669"></source>
<backingStore></backingStore>
<target dev="sda" bus="scsi"></target>
<serial></serial>
<alias name="scsi0-0-0-0"></alias>
<address type="drive" controller="0" bus="0" target="0" unit="0"></address>
</disk>
Environment
- Red Hat Enterprise Virtualization 3.5
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