https://community.extremenetworks.com/t5/extremewireless-identifi/c25-boot-issue/m-p/52957#M5823 Hello Sachu, <BR /> <BR /> If you reboot the controller with a serial console connection, do you see the Controller and Controller Rescue ? This article has steps to take once at that menu. <BR /> <BR /> <A href="https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-revert-the-controller-image-Using-Rescue-Image" target="_blank" rel="nofollow noreferrer noopener">https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-revert-the-controller-image-Using-R...</A><BR /> <BR /> If you cannot get to that menu, I would suggest giving a call to GTAC and opening a case to look further into this. <BR /> <BR /> <A href="https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-contact-Extreme-Networks-Global-Technical-Assistance-Center-GTAC" target="_blank" rel="nofollow noreferrer noopener">https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-contact-Extreme-Networks-Global-Tec...</A><BR /> <BR /> Regards, <BR /> Jason Thu, 11 Aug 2016 01:02:00 GMT Jason1 2016-08-11T01:02:00Z https://community.extremenetworks.com/t5/extremewireless-identifi/c25-boot-issue/m-p/52956#M5822 Hi, <BR /> <BR /> Can anyone provide any support to fix the below issue in C25 controller. <BR /> <BR /> VFS: Cannot open root device "sda1" or unknown-block(0,0)Please append a correct "root=" boot option; here are the available partitions:<BR /> Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)<BR /> <BR /> it is not giving me option to selection "Controller Rescue"<BR /> <BR /> Tue, 09 Aug 2016 11:55:00 GMT https://community.extremenetworks.com/t5/extremewireless-identifi/c25-boot-issue/m-p/52956#M5822 Sachu 2016-08-09T11:55:00Z https://community.extremenetworks.com/t5/extremewireless-identifi/c25-boot-issue/m-p/52957#M5823 Hello Sachu, <BR /> <BR /> If you reboot the controller with a serial console connection, do you see the Controller and Controller Rescue ? This article has steps to take once at that menu. <BR /> <BR /> <A href="https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-revert-the-controller-image-Using-Rescue-Image" target="_blank" rel="nofollow noreferrer noopener">https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-revert-the-controller-image-Using-R...</A><BR /> <BR /> If you cannot get to that menu, I would suggest giving a call to GTAC and opening a case to look further into this. <BR /> <BR /> <A href="https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-contact-Extreme-Networks-Global-Technical-Assistance-Center-GTAC" target="_blank" rel="nofollow noreferrer noopener">https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-contact-Extreme-Networks-Global-Tec...</A><BR /> <BR /> Regards, <BR /> Jason Thu, 11 Aug 2016 01:02:00 GMT https://community.extremenetworks.com/t5/extremewireless-identifi/c25-boot-issue/m-p/52957#M5823 Jason1 2016-08-11T01:02:00Z