From f528fdfdb6e0b04c275711a3625f49c765731d13 Mon Sep 17 00:00:00 2001
From: "Gupta, Surya" <Surya.Gupta@netapp.com>
Date: Thu, 6 Aug 2026 22:34:06 +0530
Subject: [PATCH 1/6] [CSTACKEX-233] Subsequent VM Creation is failing for
 ISCSI Storage Pool on Oracle Linux

---
 .../kvm/storage/IscsiAdmStorageAdaptor.java   | 61 +++++++++++++++++--
 1 file changed, 57 insertions(+), 4 deletions(-)

diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
index 495ae45a2896..d8ed59a4e66a 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
@@ -47,6 +47,9 @@ public class IscsiAdmStorageAdaptor implements StorageAdaptor {
 
     private static final Map<String, KVMStoragePool> MapStorageUuidToStoragePool = new HashMap<>();
 
+    /** iscsiadm's ISCSI_ERR_NO_OBJS_FOUND: returned by "-m session" when no session is established. */
+    private static final int ISCSI_ERR_NO_OBJS_FOUND = 21;
+
     @Override
     public KVMStoragePool createStoragePool(String uuid, String host, int port, String path, String userInfo, StoragePoolType storagePoolType, Map<String, String> details, boolean isPrimaryStorage) {
         IscsiAdmStoragePool storagePool = new IscsiAdmStoragePool(uuid, host, port, storagePoolType, this);
@@ -126,6 +129,8 @@ public boolean connectPhysicalDisk(String volumeUuid, KVMStoragePool pool, Map<S
         final int port = pool.getSourcePort();
         final String iqn = getIqn(volumeUuid);
 
+        final boolean sessionAlreadyActive = isIscsiSessionActive(iqn, host, port);
+
         // Always try to login; treat benign outcomes as success (idempotent)
         iScsiAdmCmd = new Script(true, "iscsiadm", 0, logger);
         iScsiAdmCmd.add("-m", "node");
@@ -139,8 +144,11 @@ public boolean connectPhysicalDisk(String volumeUuid, KVMStoragePool pool, Map<S
             return false;
         }
 
-        // If the session already existed, a newly mapped LUN won't be visible until a rescan.
-        if (result != null) {
+        // Login output alone is unreliable when already logged in (empty output => null).
+        final boolean sessionPreExisted = sessionAlreadyActive || (result != null);
+
+        if (sessionPreExisted) {
+            logger.info("sessionPreExisted : performing rescan explicitely");
             rescanIscsiSessions(iqn, host, port);
         }
 
@@ -156,6 +164,11 @@ public boolean connectPhysicalDisk(String volumeUuid, KVMStoragePool pool, Map<S
         // isn't solved here, but made highly unlikely to be a problem).
         waitForDiskToBecomeAvailable(volumeUuid, pool);
 
+        if (getPhysicalDisk(volumeUuid, pool).getSize() <= 0) {
+            logger.warn("iSCSI device not ready for target {} at {}:{} after wait", volumeUuid, host, port);
+            return false;
+        }
+
         return true;
     }
 
@@ -195,6 +208,37 @@ boolean handleLoginResult(String result, String volumeUuid) {
         return false;
     }
 
+    /**
+     * Checks whether a session to the given target and portal is already established.
+     *
+     * "iscsiadm -m session" exits with ISCSI_ERR_NO_OBJS_FOUND when no session exists, which is a
+     * normal outcome here, so that exit value is ignored and the output is taken from the parser.
+     */
+    private boolean isIscsiSessionActive(String iqn, String host, int port) {
+        Script sessionCmd = new Script(true, "iscsiadm", 0, logger);
+        sessionCmd.add("-m", "session");
+
+        OutputInterpreter.AllLinesParser parser = new OutputInterpreter.AllLinesParser();
+
+        sessionCmd.executeIgnoreExitValue(parser, ISCSI_ERR_NO_OBJS_FOUND);
+
+        String sessions = parser.getLines();
+
+        if (StringUtils.isBlank(sessions)) {
+            return false;
+        }
+
+        String portal = host + ":" + port;
+
+        for (String line : sessions.split("\n")) {
+            if (line.contains(iqn) && line.contains(portal)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     private void rescanIscsiSessions(String iqn, String host, int port) {
         Script rescanCmd = new Script(true, "iscsiadm", 0, logger);
         rescanCmd.add("-m", "node");
@@ -290,8 +334,17 @@ public KVMPhysicalDisk getPhysicalDisk(String volumeUuid, KVMStoragePool pool) {
 
     private long getDeviceSize(String deviceByPath) {
         try {
-            if (!Files.exists(Paths.get(deviceByPath))) {
-                logger.debug("Device by-path does not exist yet: " + deviceByPath);
+            Path devicePath = Paths.get(deviceByPath);
+            if (!Files.exists(devicePath)) {
+                logger.debug("Device by-path does not exist yet: {}", deviceByPath);
+                return 0L;
+            }
+            if (Files.isRegularFile(devicePath)) {
+                logger.warn("Removing corrupt regular file at iSCSI by-path {} (expected block device symlink)", deviceByPath);
+                return 0L;
+            }
+            if (!Files.isSymbolicLink(devicePath)) {
+                logger.warn("Path {} exists but is not an iSCSI block device symlink", deviceByPath);
                 return 0L;
             }
         } catch (Exception ex) {

From f77f997221439f3175ad94002f16969ea050f1e3 Mon Sep 17 00:00:00 2001
From: "Gupta, Surya" <Surya.Gupta@netapp.com>
Date: Fri, 7 Aug 2026 16:13:02 +0530
Subject: [PATCH 2/6] [CSTACKEX-233] Added session exists error code check

---
 .../kvm/storage/IscsiAdmStorageAdaptor.java   | 47 +++++++++++--------
 1 file changed, 28 insertions(+), 19 deletions(-)

diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
index d8ed59a4e66a..a20fce08833d 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
@@ -50,6 +50,9 @@ public class IscsiAdmStorageAdaptor implements StorageAdaptor {
     /** iscsiadm's ISCSI_ERR_NO_OBJS_FOUND: returned by "-m session" when no session is established. */
     private static final int ISCSI_ERR_NO_OBJS_FOUND = 21;
 
+    /** iscsiadm's ISCSI_ERR_SESS_EXISTS: returned by "--login" when the session is already logged in (e.g. Ubuntu). */
+    private static final int ISCSI_SESSION_EXISTS_CODE = 15;
+
     @Override
     public KVMStoragePool createStoragePool(String uuid, String host, int port, String path, String userInfo, StoragePoolType storagePoolType, Map<String, String> details, boolean isPrimaryStorage) {
         IscsiAdmStoragePool storagePool = new IscsiAdmStoragePool(uuid, host, port, storagePoolType, this);
@@ -93,12 +96,16 @@ public KVMPhysicalDisk createPhysicalDisk(String volumeUuid, KVMStoragePool pool
 
     @Override
     public boolean connectPhysicalDisk(String volumeUuid, KVMStoragePool pool, Map<String, String> details, boolean isVMMigrate) {
+        final String host = pool.getSourceHost();
+        final int port = pool.getSourcePort();
+        final String iqn = getIqn(volumeUuid);
+
         // ex. sudo iscsiadm -m node -T iqn.2012-03.com.test:volume1 -p 192.168.233.10:3260 -o new
         Script iScsiAdmCmd = new Script(true, "iscsiadm", 0, logger);
 
         iScsiAdmCmd.add("-m", "node");
-        iScsiAdmCmd.add("-T", getIqn(volumeUuid));
-        iScsiAdmCmd.add("-p", pool.getSourceHost() + ":" + pool.getSourcePort());
+        iScsiAdmCmd.add("-T", iqn);
+        iScsiAdmCmd.add("-p", host + ":" + port);
         iScsiAdmCmd.add("-o", "new");
 
         String result = iScsiAdmCmd.execute();
@@ -125,13 +132,11 @@ public boolean connectPhysicalDisk(String volumeUuid, KVMStoragePool pool, Map<S
             }
         }
 
-        final String host = pool.getSourceHost();
-        final int port = pool.getSourcePort();
-        final String iqn = getIqn(volumeUuid);
-
         final boolean sessionAlreadyActive = isIscsiSessionActive(iqn, host, port);
+        logger.debug("iSCSI session active check for target {} at {}:{}: {}", iqn, host, port, sessionAlreadyActive);
 
-        // Always try to login; treat benign outcomes as success (idempotent)
+        // Always try to login; treat benign outcomes as success (idempotent).
+        // Ubuntu returns ISCSI_ERR_SESS_EXISTS (15) when already logged in; Oracle often returns 0 with no output.
         iScsiAdmCmd = new Script(true, "iscsiadm", 0, logger);
         iScsiAdmCmd.add("-m", "node");
         iScsiAdmCmd.add("-T", iqn);
@@ -139,16 +144,17 @@ public boolean connectPhysicalDisk(String volumeUuid, KVMStoragePool pool, Map<S
         iScsiAdmCmd.add("--login");
 
         result = iScsiAdmCmd.execute();
+        final boolean sessionPreExisted = (iScsiAdmCmd.getExitValue() == ISCSI_SESSION_EXISTS_CODE) || sessionAlreadyActive;
 
-        if (!handleLoginResult(result, volumeUuid)) {
+        if (!handleLoginResult(result, sessionPreExisted, volumeUuid)) {
             return false;
         }
 
-        // Login output alone is unreliable when already logged in (empty output => null).
-        final boolean sessionPreExisted = sessionAlreadyActive || (result != null);
-
+        // Newly mapped LUNs on an existing session are invisible until rescan.
+        // Prefer the pre-login session check (required on Oracle, where re-login exits 0).
+        // Also treat ISCSI_ERR_SESS_EXISTS as a hint (Ubuntu).
         if (sessionPreExisted) {
-            logger.info("sessionPreExisted : performing rescan explicitely");
+            logger.debug("iSCSI session for target {} at {}:{} pre-existed, performing rescan", iqn, host, port);
             rescanIscsiSessions(iqn, host, port);
         }
 
@@ -192,16 +198,19 @@ boolean handleNodeCreateResult(String result, String volumeUuid) {
 
     /**
      * Checks the result of an iscsiadm login command.
-     * Returns true if the login succeeded or session already exists, false on failure.
+     * Returns true if the session already existed (pre-check and/or ISCSI_ERR_SESS_EXISTS)
+     * or login succeeded with no error output, false on failure.
+     *
+     * sessionPreExisted must be checked first: on Ubuntu, re-login exits 15 with a non-null
+     * error message that would otherwise be treated as failure.
      */
-    boolean handleLoginResult(String result, String volumeUuid) {
-        if (result == null) {
-            logger.debug("Successfully logged in to iSCSI target {}", volumeUuid);
+    boolean handleLoginResult(String result, boolean sessionPreExisted, String volumeUuid) {
+        if (sessionPreExisted) {
+            logger.debug("iSCSI session already active for target {}", volumeUuid);
             return true;
         }
-        String msg = result.toLowerCase();
-        if (msg.contains("already present") || msg.contains("already logged in") || msg.contains("session exists")) {
-            logger.debug("iSCSI session already exists for target {}, proceeding", volumeUuid);
+        if (result == null) {
+            logger.debug("Successfully logged in to iSCSI target {}", volumeUuid);
             return true;
         }
         logger.debug("Failed to log in to iSCSI target {}: {}", volumeUuid, result);

From 0271cef1abf4c800177c33493bbb27f502dcead9 Mon Sep 17 00:00:00 2001
From: "Gupta, Surya" <Surya.Gupta@netapp.com>
Date: Wed, 12 Aug 2026 00:14:26 +0530
Subject: [PATCH 3/6] [CSTACKEX-233] Review Comments

---
 .../kvm/storage/IscsiAdmStorageAdaptor.java        | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
index a20fce08833d..dfce3ade5ac8 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
@@ -150,7 +150,8 @@ public boolean connectPhysicalDisk(String volumeUuid, KVMStoragePool pool, Map<S
             return false;
         }
 
-        // Newly mapped LUNs on an existing session are invisible until rescan.
+        // Newly mapped LUNs on an existing session are invisible until rescan, while a session
+        // created by the login above already exposes them.
         // Prefer the pre-login session check (required on Oracle, where re-login exits 0).
         // Also treat ISCSI_ERR_SESS_EXISTS as a hint (Ubuntu).
         if (sessionPreExisted) {
@@ -221,7 +222,7 @@ boolean handleLoginResult(String result, boolean sessionPreExisted, String volum
      * Checks whether a session to the given target and portal is already established.
      *
      * "iscsiadm -m session" exits with ISCSI_ERR_NO_OBJS_FOUND when no session exists, which is a
-     * normal outcome here, so that exit value is ignored and the output is taken from the parser.
+     * normal outcome here. Any other non-zero exit is logged and treated as not confirmed active.
      */
     private boolean isIscsiSessionActive(String iqn, String host, int port) {
         Script sessionCmd = new Script(true, "iscsiadm", 0, logger);
@@ -231,6 +232,13 @@ private boolean isIscsiSessionActive(String iqn, String host, int port) {
 
         sessionCmd.executeIgnoreExitValue(parser, ISCSI_ERR_NO_OBJS_FOUND);
 
+        int exitValue = sessionCmd.getExitValue();
+        if (exitValue != 0 && exitValue != ISCSI_ERR_NO_OBJS_FOUND) {
+            logger.warn("Unable to determine iSCSI session state for target {} at {}:{}: 'iscsiadm -m session' exited with {}",
+                    iqn, host, port, exitValue);
+            return false;
+        }
+
         String sessions = parser.getLines();
 
         if (StringUtils.isBlank(sessions)) {
@@ -349,7 +357,7 @@ private long getDeviceSize(String deviceByPath) {
                 return 0L;
             }
             if (Files.isRegularFile(devicePath)) {
-                logger.warn("Removing corrupt regular file at iSCSI by-path {} (expected block device symlink)", deviceByPath);
+                logger.warn("Found a corrupt regular file at iSCSI by-path {} (expected block device symlink); it must be removed manually", deviceByPath);
                 return 0L;
             }
             if (!Files.isSymbolicLink(devicePath)) {

From 71a6730b878d5866a63e98170000db57aad51a18 Mon Sep 17 00:00:00 2001
From: "Gupta, Surya" <Surya.Gupta@netapp.com>
Date: Mon, 17 Aug 2026 23:31:41 +0530
Subject: [PATCH 4/6] [CSTACKEX-233] Address Review Comments

---
 .../kvm/storage/IscsiAdmStorageAdaptor.java   | 76 +++++++++----------
 1 file changed, 34 insertions(+), 42 deletions(-)

diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
index dfce3ade5ac8..109c54189e21 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
@@ -132,33 +132,12 @@ public boolean connectPhysicalDisk(String volumeUuid, KVMStoragePool pool, Map<S
             }
         }
 
-        final boolean sessionAlreadyActive = isIscsiSessionActive(iqn, host, port);
-        logger.debug("iSCSI session active check for target {} at {}:{}: {}", iqn, host, port, sessionAlreadyActive);
-
-        // Always try to login; treat benign outcomes as success (idempotent).
-        // Ubuntu returns ISCSI_ERR_SESS_EXISTS (15) when already logged in; Oracle often returns 0 with no output.
-        iScsiAdmCmd = new Script(true, "iscsiadm", 0, logger);
-        iScsiAdmCmd.add("-m", "node");
-        iScsiAdmCmd.add("-T", iqn);
-        iScsiAdmCmd.add("-p", host + ":" + port);
-        iScsiAdmCmd.add("--login");
-
-        result = iScsiAdmCmd.execute();
-        final boolean sessionPreExisted = (iScsiAdmCmd.getExitValue() == ISCSI_SESSION_EXISTS_CODE) || sessionAlreadyActive;
-
-        if (!handleLoginResult(result, sessionPreExisted, volumeUuid)) {
+        // Login is always attempted (idempotent). Rescan runs only if the session already existed
+        // before login (Oracle re-login exits 0; Ubuntu may return ISCSI_ERR_SESS_EXISTS).
+        if (!loginOrRescanExistingSession(iqn, host, port, volumeUuid)) {
             return false;
         }
 
-        // Newly mapped LUNs on an existing session are invisible until rescan, while a session
-        // created by the login above already exposes them.
-        // Prefer the pre-login session check (required on Oracle, where re-login exits 0).
-        // Also treat ISCSI_ERR_SESS_EXISTS as a hint (Ubuntu).
-        if (sessionPreExisted) {
-            logger.debug("iSCSI session for target {} at {}:{} pre-existed, performing rescan", iqn, host, port);
-            rescanIscsiSessions(iqn, host, port);
-        }
-
         // There appears to be a race condition where logging in to the iSCSI volume via iscsiadm
         // returns success before the device has been added to the OS.
         // What happens is you get logged in and the device shows up, but the device may not
@@ -169,9 +148,7 @@ public boolean connectPhysicalDisk(String volumeUuid, KVMStoragePool pool, Map<S
         // After a certain number of tries and a certain waiting period in between tries,
         // this method could still return (it should not block indefinitely) (the race condition
         // isn't solved here, but made highly unlikely to be a problem).
-        waitForDiskToBecomeAvailable(volumeUuid, pool);
-
-        if (getPhysicalDisk(volumeUuid, pool).getSize() <= 0) {
+        if (!waitForDiskToBecomeAvailable(volumeUuid, pool)) {
             logger.warn("iSCSI device not ready for target {} at {}:{} after wait", volumeUuid, host, port);
             return false;
         }
@@ -198,16 +175,31 @@ boolean handleNodeCreateResult(String result, String volumeUuid) {
     }
 
     /**
-     * Checks the result of an iscsiadm login command.
-     * Returns true if the session already existed (pre-check and/or ISCSI_ERR_SESS_EXISTS)
-     * or login succeeded with no error output, false on failure.
+     * Checks existing session state, performs login, and rescans only if the session already existed.
+     *
+     * Login is always attempted (idempotent). A pre-login session check is required on Oracle,
+     * where re-login often exits 0; Ubuntu may instead return ISCSI_ERR_SESS_EXISTS (15).
+     * Session-preexisted must be treated as success first: on Ubuntu, re-login exits 15 with a
+     * non-null error message that would otherwise be treated as failure.
      *
-     * sessionPreExisted must be checked first: on Ubuntu, re-login exits 15 with a non-null
-     * error message that would otherwise be treated as failure.
+     * @return true if login succeeded (and rescan ran when needed), false on login failure
      */
-    boolean handleLoginResult(String result, boolean sessionPreExisted, String volumeUuid) {
+    private boolean loginOrRescanExistingSession(String iqn, String host, int port, String volumeUuid) {
+        boolean sessionAlreadyActive = isIscsiSessionActive(iqn, host, port);
+        logger.debug("iSCSI session active check for target {} at {}:{}: {}", iqn, host, port, sessionAlreadyActive);
+
+        Script iScsiAdmCmd = new Script(true, "iscsiadm", 0, logger);
+        iScsiAdmCmd.add("-m", "node");
+        iScsiAdmCmd.add("-T", iqn);
+        iScsiAdmCmd.add("-p", host + ":" + port);
+        iScsiAdmCmd.add("--login");
+
+        String result = iScsiAdmCmd.execute();
+        boolean sessionPreExisted = (iScsiAdmCmd.getExitValue() == ISCSI_SESSION_EXISTS_CODE) || sessionAlreadyActive;
+
         if (sessionPreExisted) {
-            logger.debug("iSCSI session already active for target {}", volumeUuid);
+            logger.debug("iSCSI session for target {} at {}:{} pre-existed, performing rescan", iqn, host, port);
+            rescanIscsiSessions(iqn, host, port);
             return true;
         }
         if (result == null) {
@@ -229,9 +221,7 @@ private boolean isIscsiSessionActive(String iqn, String host, int port) {
         sessionCmd.add("-m", "session");
 
         OutputInterpreter.AllLinesParser parser = new OutputInterpreter.AllLinesParser();
-
         sessionCmd.executeIgnoreExitValue(parser, ISCSI_ERR_NO_OBJS_FOUND);
-
         int exitValue = sessionCmd.getExitValue();
         if (exitValue != 0 && exitValue != ISCSI_ERR_NO_OBJS_FOUND) {
             logger.warn("Unable to determine iSCSI session state for target {} at {}:{}: 'iscsiadm -m session' exited with {}",
@@ -240,13 +230,11 @@ private boolean isIscsiSessionActive(String iqn, String host, int port) {
         }
 
         String sessions = parser.getLines();
-
         if (StringUtils.isBlank(sessions)) {
             return false;
         }
 
         String portal = host + ":" + port;
-
         for (String line : sessions.split("\n")) {
             if (line.contains(iqn) && line.contains(portal)) {
                 return true;
@@ -270,19 +258,23 @@ private void rescanIscsiSessions(String iqn, String host, int port) {
         }
     }
 
-    private void waitForDiskToBecomeAvailable(String volumeUuid, KVMStoragePool pool) {
+    private boolean waitForDiskToBecomeAvailable(String volumeUuid, KVMStoragePool pool) {
         int numberOfTries = 10;
         int timeBetweenTries = 1000;
+        long deviceSize = 0;
 
-        while (getPhysicalDisk(volumeUuid, pool).getSize() == 0 && numberOfTries > 0) {
+        while ((deviceSize = getPhysicalDisk(volumeUuid, pool).getSize()) == 0 && numberOfTries > 0) {
             numberOfTries--;
 
             try {
                 Thread.sleep(timeBetweenTries);
-            } catch (Exception ex) {
-                // don't do anything
+            } catch (InterruptedException ex) {
+                logger.warn("Interrupted while waiting for iSCSI device {} to become available", volumeUuid, ex);
+                return false;
             }
         }
+
+        return deviceSize > 0;
     }
 
     private void waitForDiskToBecomeUnavailable(String host, int port, String iqn, String lun) {

From f87fdc0a8c8d33f9a8c0e749f351a3dc8952e8f9 Mon Sep 17 00:00:00 2001
From: "Gupta, Surya" <Surya.Gupta@netapp.com>
Date: Thu, 20 Aug 2026 01:24:43 +0530
Subject: [PATCH 5/6] [CSTACKEX-233] Address Review Comments

---
 .../hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java     | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
index 109c54189e21..7813747e1a11 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
@@ -148,6 +148,9 @@ public boolean connectPhysicalDisk(String volumeUuid, KVMStoragePool pool, Map<S
         // After a certain number of tries and a certain waiting period in between tries,
         // this method could still return (it should not block indefinitely) (the race condition
         // isn't solved here, but made highly unlikely to be a problem).
+        // If the by-path is missing or is a regular file (not the iSCSI block symlink), size
+        // stays 0. Return false so connect does not succeed and a raw file is not created at
+        // that by-path in place of the real LUN device.
         if (!waitForDiskToBecomeAvailable(volumeUuid, pool)) {
             logger.warn("iSCSI device not ready for target {} at {}:{} after wait", volumeUuid, host, port);
             return false;
@@ -233,10 +236,8 @@ private boolean isIscsiSessionActive(String iqn, String host, int port) {
         if (StringUtils.isBlank(sessions)) {
             return false;
         }
-
-        String portal = host + ":" + port;
         for (String line : sessions.split("\n")) {
-            if (line.contains(iqn) && line.contains(portal)) {
+            if (line.contains(iqn) && line.contains(host)) {
                 return true;
             }
         }

From 777528ad559702a1146f05325b0ec7022771edee Mon Sep 17 00:00:00 2001
From: "Gupta, Surya" <Surya.Gupta@netapp.com>
Date: Thu, 20 Aug 2026 14:11:52 +0530
Subject: [PATCH 6/6] [CSTACKEX-233] Added comment for \n split

---
 .../cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java   | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
index 7813747e1a11..3ec7407d1098 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/IscsiAdmStorageAdaptor.java
@@ -236,6 +236,9 @@ private boolean isIscsiSessionActive(String iqn, String host, int port) {
         if (StringUtils.isBlank(sessions)) {
             return false;
         }
+        // AllLinesParser uses BufferedReader.readLine() (strips \n, \r\n, and \r) and then
+        // appends "\n" after each session. split("\n") depends on that separator to walk
+        // one session per line when multiple sessions are listed.
         for (String line : sessions.split("\n")) {
             if (line.contains(iqn) && line.contains(host)) {
                 return true;