When I create multiple snapshots on a logical volume that is being busy written to, the lvcreate command becomes dead when the third or fourth snapshot is created on a single logical volume. The process that writes to the logical volume also dies. “Dies” here means the program doesn’t return, nor can it be killed by pressing CTRL-C or “kill” command. The system is still responsive though, and I can login to run some other commands. But once the error condition happens if I run any command that accesses the logical volume, it also dies.
This problem was found on Fedora Core 4 (2.6.11-1). I also tried it with the unstable dm patches and it doesn’t cure.
Is this a known problem? I’ve searched the Internet and found some folks discussing I/O scheduler issue in 2.6 kernel snapshot. Any plan to fix it?