From: "Daniel Jitnah" <[email protected]> > 1.Linux (Debian Wheezy) running on a cloud server > 2.Everything working fine for weeks/months > 3.Last nite, for some reason all disk writes to server stops > 4.Even root cannot write to anywhere on the disk, and plenty of space > left on disk (~80%) > All file permissions look OK. > > 5.After reboot all return to normal.(ie problem is fixed) > > My questions: > > Is it fair to assume that the problem was caused by something that the > cloud provider has done? Or could it be something on server OS side? > > What can cause this? > > (I am thinking the virtual disk hosting the VM has become readonly > somehow, but how? )
I had this in the past, with a VirtualBox VM (Ubuntu Server) on FreeBSD ZFS. The performance of the ZFS became very bad - resulting in disk write timeouts in the Ubuntu VM. The Ubuntu server assumed a faulty disk and remounted the disk as read-only to prevent further damage. Although you are very unlikely to have FreeBSD/ZFS underneath there are other ways to "produce" high I/O latency. If so you should find these disk I/O related errors in your kernel logs. I am afraid there is not much you can do (if you do not run the host system). It only needs a short period with this problem and your system becomes unresponsive. Monitoring.. I did not do that for the read/only mount but all services running on that VM turned red on the Icinga webpage. Regards Peter _______________________________________________ luv-main mailing list [email protected] http://lists.luv.asn.au/listinfo/luv-main
