**Bug fixes and minor changes**
* osxfs: fixed a malfunction of new directories that have the same name as an old directory that is still open
* osxfs: rename events now trigger DELETE and/or MODIFY `inotify` events (saving with TextEdit works now)
* slirp: support up to 8 external DNS servers
* slirp: reduce the number of sockets used by UDP NAT, reduce the probability that NAT rules will time out earlier than expected
* The app warns user if BlueStacks is installed (potential kernel panic)
**Known issues**
* Several problems have been reported on macOS 10.12 Sierra and are being investigated. This includes failure to launch the app and being unable to upgrade to a new version.
* `Docker.app` sometimes uses 200% CPU after macOS wakes up from sleep mode. The issue is being investigated. The workaround is to restart `Docker.app`.
* There are a number of issues with the performance of directories bind-mounted with `osxfs`. In particular, writes of small blocks and traversals of large
directories are currently slow. Additionally, containers that perform large
numbers of directory operations, such as repeated scans of large directory
trees, may suffer from poor performance. For more information and workarounds, see the bullet on performance of bind-mounted directories in [Known Issues](/manuals/desktop/troubleshoot-and-support/troubleshoot/known-issues.md) in Troubleshooting.
* Under some unhandled error conditions, `inotify` event delivery can fail and become permanently disabled. The workaround is to restart `Docker.app`.
### Beta 23 Release Notes (2016-08-16 1.12.1-rc1-beta23)
**Upgrades**
* Docker 1.12.1-rc1
* Linux kernel 4.4.17
* AUFS 20160808
**Bug fixes and minor changes**
* Moby: use default sysfs settings, transparent huge pages disabled
* Moby: cgroup mount to support systemd in containers
* osxfs: fixed an issue that caused `inotify` failure and crashes
* osxfs: fixed a directory fd leak
* Zsh completions
**Known issues**
* Docker for Mac is not supported on macOS 10.12 Sierra
* Docker.app sometimes uses 200% CPU after macOS wakes up from sleep mode. The issue is being investigated. The workaround is to restart Docker.app
* There are a number of issues with the performance of directories bind-mounted with `osxfs`. In particular, writes of small blocks and traversals of large directories are currently slow. Additionally, containers that perform large numbers of directory operations, such as repeated scans of large directory trees, may suffer from poor performance. For more information and workarounds, see the bullet on performance of bind-mounted directories in [Known Issues](/manuals/desktop/troubleshoot-and-support/troubleshoot/known-issues.md) in Troubleshooting.
* Under some unhandled error conditions, `inotify` event delivery can fail and become permanently disabled. The workaround is to restart Docker.app
### Beta 22 Release Notes (2016-08-11 1.12.0-beta22)
**Upgrades**
* Linux kernel to 4.4.16
**Bug fixes and minor changes**
* Increase Moby fs.file-max to 524288
* Use Mac System Configuration database to detect DNS
* HyperKit updated with dtrace support and lock fixes
* Fix Moby Diagnostics and Update Kernel
* UI Fixes
* osxfs: fix socket chowns
**Known issues**
* Docker.app sometimes uses 200% CPU after macOS wakes up from sleep mode. The issue is being investigated. The workaround is to restart Docker.app
* There are a number of issues with the performance of directories bind-mounted with `osxfs`. In particular, writes of small blocks and traversals of large directories are currently slow. Additionally, containers that perform large numbers of directory operations, such as repeated scans of large directory trees, may suffer from poor performance. More information is available in [Known Issues](/manuals/desktop/troubleshoot-and-support/troubleshoot/known-issues.md).
* Under some unhandled error conditions, `inotify` event delivery can fail and become permanently disabled. The workaround is to restart Docker.app