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--- soc:2009:pravin:journal:bkodebianiscsi [2009/07/19 06:41]
less1
+++ soc:2009:pravin:journal:bkodebianiscsi [2009/09/25 19:37] (current)
less1
@@ Line 188: / Line 188: @@
 </code>
 This is what killing the iscsiadm imatuarly.
+==== Checking the code of open-iscsi ====
+With help of stephana, the likely problem is located at following location
+<code>
+stefanha: http://git.kernel.org/?p=linux/kernel/git/mnc/open-iscsi.git;a=blob;f=usr/mgmt_ipc.c;h=e784bcac019a84522e62beff1b49b1ca62e37f5a;hb=HEAD
+(07/19/2009 04:34:21 PM) stefanha: less1: Perhaps you're hitting this:
+(07/19/2009 04:34:27 PM) stefanha: http://git.kernel.org/?p=linux/kernel/git/mnc/open-iscsi.git;a=blob;f=usr/mgmt_ipc.c;h=e784bcac019a84522e62beff1b49b1ca62e37f5a;hb=HEAD#l549
+(07/19/2009 04:34:31 PM) stefanha: if (!mgmt_peeruser(fd, user) || strncmp(user, "root", PEERUSER_MAX)) {
+(07/19/2009 04:34:43 PM) stefanha: write(2) will return EPIPE if the UNIX domain socket was closed.
+(07/19/2009 04:35:17 PM) stefanha: mgmt_peeruser() is defined here: http://git.kernel.org/?p=linux/kernel/git/mnc/open-iscsi.git;a=blob;f=usr/mgmt_ipc.c;h=e784bcac019a84522e62beff1b49b1ca62e37f5a;hb=HEAD#l342
+(07/19/2009 04:38:15 PM) less1: stefanha: is it checking if I have root privilages? I am not sure if I understand which peeruser credential is it refering.
+(07/19/2009 04:40:08 PM) stefanha: Your user name must be "root".
+(07/19/2009 04:40:25 PM) stefanha: Otherwise iscsid will not accept commands from the UNIX domain socket.
+</code>
+=== Possible solution : hacking open-iscsi ===
+modified the ''iscsiadm'' code so that, it will not fail when username is not ''root''.\\
+With is modification, the discovery part is working, but now there is error at login part. Following is the error.
+<code>
+connection2:0: Could not create connection due to crc32c loading error.  Make sure the crc32c module is build as module into the kernel.
+</code>
+The first attempt will be to download the kernel module from Live CD of debian after booting it from CD.\\
+--- Doing it
+===== Working Solution =====
+There was need for two extra kernel modules
+  - libcrc32c.ko
+  - crc32c.ko
+Fetched these modules from live-CD and added them.\\
+There as also need for small sleep after ''iscsiadm --login'' as ''/dev/sda'' was taking little time to appear.\\
+This was handled by adding ''sleep 2''\\
+Two new parameters were introduced
+  - ''iscsifs=<IP:PORT>''  iscsi server IP and port number
+  - ''target=<targetname>'' the iscsi target name of the disk (entire name is not needed, some part which can uniquely identify apart from other disks exported at same machine)
+===== Remote ISCSI =====
+Following are the errors that I get when connecting to remote iscsi
+<code>
+Connection1:0: ping timeout of 5 secs expired, last rx 307737, last ping 308987, now 310237
+Connection1:0: detected conn error (1011)
+SQUASHFS error : Unable to read page, block 0x1b392
+Bus error
+</code>
+Most of these errors are related to timing, and I believe that
+these errors are there because of delays in accessing required data.
+===== Target behaviour =====
+sometimes, you may get following error when logging in with iscsiadm
+<code>
+iscsiadm -m node --targetname "${targetname}" --portal "${ISCSIFS}" --login
+records not found!.
+</code>
+this is because the ${ISCSIFS} is not IP but dnsname.
+Dnsname may work with ''iscsiadm -m discovery -t st -p "${ISCSIFS}" ''
+but it may verywell fail when same dnsname is given to login.
+[[http://groups.google.com/group/open-iscsi/browse_thread/thread/c556508505ecc461|mailing list discussion]]
+==== Solution ====
+Dont use ''--portal "${ISCSIFS}"'' option, use
+<code>
+iscsiadm -m node --targetname "${targetname}" --login
+</code>

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