xen-org/xen-api — pull request #838 by johnelse (2012-08-17 13:56:25+00:00)
Title: CA-88290: VDI.attach for SXM mirroring should be read only.

This allows us to attach RO discs for mirroring - attaching them RW will
fail.

Even if the disk is already attached RW, we only need a RO attach for
mirroring.