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Who When What Removed Added
Zhang Yi 2016-09-20 05:05:24 UTC CC yizhan
QA Contact storage-qe yizhan
Ben Marzinski 2016-09-20 16:47:05 UTC Status NEW ASSIGNED
Zhang Yi 2016-09-21 02:23:28 UTC CC nkshirsa
Flags needinfo?(nkshirsa)
nikhil kshirsagar 2016-09-22 03:31:33 UTC Flags needinfo?(nkshirsa)
Ben Marzinski 2016-10-17 18:00:07 UTC Status ASSIGNED MODIFIED
Fixed In Version device-mapper-multipath-0.4.9-94.el6
Doc Text Feature: Multipath how has the "disable_changed_wwids" multipath.conf option. If this is set to "yes", multipathd will monitor path devices, and if their wwid changes, it will disable them until the wwid changes back

Reason: If a LUN gets remapped while it is multipathed, it is possible in some cases for IO to get written to the wrong LUN, and corruption to occur. Multipathd can detect this by noticing that the LUN wwid has changed, and disable access to the device (hopefully before any corruption can occur).

Result: Multipathd now disables access to devices if they have been remapped (and disable_changed_wwids is set). This can avoid corruption in some cases. Due to the gap between when the LUN is remapped, and when multipathd is notified that the device has changed, there is still a risk of corruption in some cases, and remapping in-use LUNs is still not supported.
Doc Type If docs needed, set a value Enhancement
errata-xmlrpc 2016-11-10 23:55:31 UTC Status MODIFIED ON_QA
Ben Marzinski 2016-12-07 19:26:02 UTC Doc Type Enhancement Release Note
Zhang Yi 2016-12-08 03:48:26 UTC QA Contact yizhan lilin
Lenka Špačková 2016-12-12 11:14:50 UTC Docs Contact mnavrati
Lin Li 2017-01-05 08:27:01 UTC Flags needinfo?(bmarzins)
Lin Li 2017-01-05 08:31:43 UTC Flags needinfo?(nkshirsa)
nikhil kshirsagar 2017-01-05 08:47:26 UTC Flags needinfo?(bmarzins) needinfo?(nkshirsa)
Milan Navratil 2017-01-05 20:17:54 UTC Doc Text Feature: Multipath how has the "disable_changed_wwids" multipath.conf option. If this is set to "yes", multipathd will monitor path devices, and if their wwid changes, it will disable them until the wwid changes back

Reason: If a LUN gets remapped while it is multipathed, it is possible in some cases for IO to get written to the wrong LUN, and corruption to occur. Multipathd can detect this by noticing that the LUN wwid has changed, and disable access to the device (hopefully before any corruption can occur).

Result: Multipathd now disables access to devices if they have been remapped (and disable_changed_wwids is set). This can avoid corruption in some cases. Due to the gap between when the LUN is remapped, and when multipathd is notified that the device has changed, there is still a risk of corruption in some cases, and remapping in-use LUNs is still not supported. 		The "disable_changed_wwids" `multipath.conf` option is now available in multipath to avoid data corruption

The multipath tool now has the "disable_changed_wwids" `multipath.conf` option. If "disable_changed_wwids" is set to "yes", the *multipathd* service monitors path devices, and if their World Wide Identifier (WWID) changes, *multipathd* disables access to the path devices until the WWID changes back.

If a Logical Unit Number (LUN) is remapped during a multipath operation, it is possible in some cases for I/O to be written to an incorrect LUN, which leads to corruption. Writing to an incorrect LUN can be detected by *multipathd* that registers a change of the LUN WWID, and disables access to the device. Due to the gap between when the LUN is remapped, and when *multipathd* is notified that the device has changed, there is still a risk of corruption in some cases, and remapping in-use LUNs is still not supported.
Flags needinfo?(bmarzins)
Ben Marzinski 2017-01-06 04:58:23 UTC Doc Text The "disable_changed_wwids" `multipath.conf` option is now available in multipath to avoid data corruption

The multipath tool now has the "disable_changed_wwids" `multipath.conf` option. If "disable_changed_wwids" is set to "yes", the *multipathd* service monitors path devices, and if their World Wide Identifier (WWID) changes, *multipathd* disables access to the path devices until the WWID changes back.

If a Logical Unit Number (LUN) is remapped during a multipath operation, it is possible in some cases for I/O to be written to an incorrect LUN, which leads to corruption. Writing to an incorrect LUN can be detected by *multipathd* that registers a change of the LUN WWID, and disables access to the device. Due to the gap between when the LUN is remapped, and when *multipathd* is notified that the device has changed, there is still a risk of corruption in some cases, and remapping in-use LUNs is still not supported. 		The "disable_changed_wwids" `multipath.conf` option is now available in multipath to avoid data corruption

The multipath tool now has the "disable_changed_wwids" `multipath.conf` option. If "disable_changed_wwids" is set to "yes", the *multipathd* service monitors path devices, and if their World Wide Identifier (WWID) changes, *multipathd* disables access to the path devices until the WWID changes back.

If a Logical Unit Number (LUN) is remapped while a multipath device exists on top of it, it is possible in some cases for I/O to be written to an incorrect LUN, which leads to corruption. Writing to an incorrect LUN can be detected by *multipathd* that registers a change of the LUN WWID, and disables access to the device. Due to the gap between when the LUN is remapped, and when *multipathd* is notified that the device has changed, there is still a risk of corruption in some cases, and remapping in-use LUNs is still not supported.
Flags needinfo?(bmarzins)
Milan Navratil 2017-01-06 11:28:58 UTC Doc Text The "disable_changed_wwids" `multipath.conf` option is now available in multipath to avoid data corruption

The multipath tool now has the "disable_changed_wwids" `multipath.conf` option. If "disable_changed_wwids" is set to "yes", the *multipathd* service monitors path devices, and if their World Wide Identifier (WWID) changes, *multipathd* disables access to the path devices until the WWID changes back.

If a Logical Unit Number (LUN) is remapped while a multipath device exists on top of it, it is possible in some cases for I/O to be written to an incorrect LUN, which leads to corruption. Writing to an incorrect LUN can be detected by *multipathd* that registers a change of the LUN WWID, and disables access to the device. Due to the gap between when the LUN is remapped, and when *multipathd* is notified that the device has changed, there is still a risk of corruption in some cases, and remapping in-use LUNs is still not supported. 		The "disable_changed_wwids" `multipath.conf` option is now available in multipath to avoid data corruption

The multipath tool now has the "disable_changed_wwids" `multipath.conf` option. If "disable_changed_wwids" is set to "yes", the *multipathd* service monitors path devices, and if their World Wide Identifier (WWID) changes, *multipathd* disables access to the path devices until the WWID changes back.

If a Logical Unit Number (LUN) is remapped while a multipath device exists on top of it, it is possible in some cases for I/O to be written to an incorrect LUN, which leads to corruption. Writing to an incorrect LUN can be detected by *multipathd* that registers a change of the LUN WWID, and disables access to the device.

Note that due to the gap between when the LUN is remapped, and when *multipathd* is notified that the device has changed, there is still a risk of corruption in some cases, and remapping in-use LUNs is still not supported.
Lin Li 2017-02-07 05:33:25 UTC Flags needinfo?(nkshirsa)
Lin Li 2017-02-16 06:15:04 UTC Flags needinfo?(nkshirsa)
nikhil kshirsagar 2017-02-16 06:18:37 UTC Flags needinfo?(nkshirsa) needinfo?(nkshirsa)
Lin Li 2017-02-16 06:30:13 UTC Status ON_QA VERIFIED
errata-xmlrpc 2017-03-21 01:11:03 UTC Status VERIFIED RELEASE_PENDING
errata-xmlrpc 2017-03-21 10:52:57 UTC Status RELEASE_PENDING CLOSED
Resolution --- ERRATA
Last Closed 2017-03-21 06:52:57 UTC

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