m.kumar_at_iitg.ernet.in
Date: Sat Mar 29 2008 - 03:10:01 PST
Dear sir, While trying to implement BACKUP_RESTORE policy in file checkpointing, we came across a problem. Specifically, while restarting the process from it's context file, the file opened by the process ( outfile : opened by Examples/file_counting/file_counting ) does not get created on the disk filesystem. To implement the BACKUP_RESTORE policy, we have used your function cr_mkunlinked() (in file cr_io.c ) logic, with the modification that we are not doing vfs_unlink() in our version of the function. We think that doing this should create a normal file that is not unlinked ( since we are not performing the vfs_unlink() in our version ), even if we delete the file ( outfile ) by rm command after we have taken the checkpoint. However, this does not happen. NO file gets created on the disk filesystem, but there is an entry for that file in the proc filesystem, which was getting updated after we ran cr_restart. What we wanted was this file should have been created on the disk (if removed) and should have been updated like it is being updated right now in the proc filesystem. Could you please tell us what is wrong with our modification ( removal of vfs_unlink() from your cr_mkunlinked() function ) ? Thanks, Manish Kumar & Abhinav Jha IIT Guwahati - India ----------------------------------------------------------------------------------- This email was sent from IIT Guwahati Webmail. If you are not the intended recipient, please contact the sender by email and delete all copies; your cooperation in this regard is appreciated. http://www.iitg.ac.in