<html><body bgcolor="#FFFFFF"><div></div><div>Hi, I had a question on how a target can force a path on Linux to go to "failed" state. </div><div><br></div><div>In the multipath -l output below, there are 4 paths to a device and all the paths are "active". What kind of response/sense code is required so as to make path sddd below to go from active to failed state ?</div><div><br></div><div>I guess another question is : how does device mapper recognize that a path is active or failed, in other words what sequence of SCSI opcodes is sent by Linux to discover a path and mark it dead/failed or alive ?<br><br></div><div><br><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><span>mpath153 (360060480000190102221533031303030) dm-154 EMC,SYMMETRIX</span></span><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><br></span><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><span>[size=938M][features=0][hwhandler=0][rw]</span></span><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><br></span><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><span>\_ round-robin 0 [prio=0][active]</span></span><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><br></span><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><span>\_ 3:0:<a href="x-apple-data-detectors://1" x-apple-data-detectors="true">0:11</a> sddd 70:176 [active][undef]</span></span><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><br></span><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><span>\_ 4:0:<a href="x-apple-data-detectors://2" x-apple-data-detectors="true">0:11</a> sdgt 132:144 [active][undef]</span></span><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><br></span><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><span>\_ 5:0:0:182 sdka 65:480 [active][undef]</span></span><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><br></span><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><span>\_ 6:0:0:182 sdln 68:336 [active][undef]</span></span><span class="Apple-style-span" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); font-size: medium; "><br></span><div><br></div></div><div><br></div><div>Thanks</div></body></html>