On Wed, Sep 21 2016 at 5:14am -0400, jiangyiwen <jiangyiwen@xxxxxxxxxx> wrote: > Hi guys, > > I'm sorry if someone else has already asked the same question before, but > here's what we are facing with generic multipath. > > We were evaluating SCSI-3 PR and hit the following issue: > > Our IPSAN has two controllers (C1/C2). Our host is connected to both > controllers. So we have 2 I_T nexus. The same key is registered on each I_T > nexus. When we issue SCSI-3 PR RESERE through generic multipath, the > reservation will be placed on one of the controllers (say, C1). Now if we > issue SCSI-3 PR RELEASE, generic multipath will select _only_ one of its > paths based on user defined path selection policy. The problem is that, if > the selected path leads to controller C2, which does not hold the > reservation, the reservation won't be released - and what's more, since the > reservation is done by the same host, the RELEASE command returns > successfully. So this gives us the illusion that the reservation is released > but in fact it is still there. > > I know that there's a user space tool mpathpersist that can handle this > problem by issuing release command on all available paths, but here I am > talking about doing same thing in kernel space. So my question is, is there > anyone who is working on supporting SCSI-3 PR in a multiple controller > environment? > > Please advise. Thanks in advance! Which kernel are you using? Christoph (now cc'd) has introduced a new PR api. I merged a fix from him relatively recently (commit 9c72bad1f3 "dm: call PR reserve/unreserve on each underlying device") Mike -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
