** Changed in: cloud-init Status: Fix Committed => Fix Released -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to cloud-init. https://bugs.launchpad.net/bugs/1490796
Title: [SRU] cloud-init must check/format Azure ephemeral disks each boot Status in cloud-init: Fix Released Status in cloud-init package in Ubuntu: Fix Released Status in cloud-init source package in Precise: Fix Released Status in cloud-init source package in Trusty: Fix Released Status in cloud-init source package in Vivid: Fix Released Bug description: [Impact] Sometimes when rebooting an instance in Azure, a different ephemeral disk will be presented. Azure ephemeral disks are presented as NTFS disks, but we reformat them to ext4. With the last cloud-init upload, we shifted to using /dev/disk symlinks to mount these disks (in case they are not presented as the same physical device). Unfortunately, the code that determines if we have a new ephemeral disk was not updated to handle symlinks, so never detects a new disk. [Test Case] 1) Boot an Azure instance and install the new cloud-init. 2) Change the size of the instance using the Azure web interface (as this near-guarantees that the ephemeral disk will be replaced with a new one). This will reboot the instance. 3) Once the instance is rebooted, SSH in and confirm that: a) An ext4 ephemeral disk is mounted at /mnt, and b) cloud-init.log indicates that a fabric formatted ephemeral disk was found on this boot. [Regression Potential] Limited; two LOCs change, to dereference symlinks instead of using paths verbatim. [Original Report] Ubuntu 14.04.3 (20150805) on Azure with cloud-init package 0.7.5-0ubuntu1.8. On Azure cloud-init prepares the ephemeral device as ext4 for the first boot. However, if the VM is ever moved to another Host for any reason, then a new ephemeral disk might be provided to the VM. This ephemeral disk is NTFS formatted, so for subsequent reboots cloud-init must detect and reformat the new disk as ext4. However, with cloud- init 0.7.5-0ubuntu1.8 subsequent boots may result in fuse mounted NTFS file system. This issue occurred in earlier versions of cloud-init, but was fixed with bug 1292648 (https://bugs.launchpad.net/ubuntu/+source/cloud- init/+bug/1292648). So this appears to be a regression. Repro: - Create an Ubuntu 14.04.3 VM on Azure - Resize the VM to a larger size (this typically moves the VM) - Log in and run 'blkid' to show an ntfs formatted ephemeral disk: # blkid /dev/sdb1: LABEL="Temporary Storage" UUID="A43C43DD3C43A95E" TYPE="ntfs" Expected results: - After resizing the ephemeral disk should be formatted as ext4. To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-init/+bug/1490796/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : yahoo-eng-team@lists.launchpad.net Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp