Dm-Clone to be Included in Linux Kernel

Starting from upcoming version 5.4, new module will be included, designed to clone the block devices, e.g. remote acrchive device 
23 September 2019   814

Linus Torvalds accepted into the kernel branch, on the basis of which release 5.4 is formed, the implementation of the dm-clone module with the implementation of a new handler based on Device-Mapper, which allows you to clone an existing block device. The module makes it possible to create a local copy based on a read-only block device that can be recorded during the cloning process.

As a typical application of dm-clone, is a network cloning of remote archive devices, read-only and processing I / O with large delays, to a local fast device that supports recording and processing requests with minimal delays.

The key difference from the solutions based on Unionfs and OverlayFS is that dm-clone works at the block device level, regardless of the file system used on this device, and forms a complete copy of the source device, and does not impose an additional layer in which changes are tracked. Unlike dm-mirror, the dm-clone module was originally designed to work only with the original section in read-only mode, without translating write operations to it. In dm-snapshot, a full copy is not created and there is no support for background copying. In dm-cache, a full copy is not created, write operations are forwarded, and the work boils down to caching hits. The closest in functionality is dm-thin, but it does not support background copy operations and is limited only by the use of certain types of partitions (thin-provisioning).

Oracle to Release Unbreakable Kernel R5U3

The update for the kernel, that can be used as alternative for Red Hat Enterprise Linux used in the Oracle Linux is based on the Linux 4.14 
25 March 2020   194

Oracle has released the third functional update for the Unbreakable Enterprise Kernel R5 kernel, positioned for use in the Oracle Linux distribution as an alternative to the regular kernel package from Red Hat Enterprise Linux. The kernel is available for x86_64 and ARM64 architectures (aarch64). Kernel sources, including breakdowns into individual patches, are published in the public Oracle Git repository.

The Unbreakable Enterprise Kernel 5 package is based on the Linux 4.14 kernel (UEK R4 was based on the 4.1 kernel), which is supplemented with new features, optimizations and fixes, as well as tested for compatibility with most applications running in RHEL and specially optimized for working with industrial software and Oracle hardware. Installation and src packages with the UEK R5U1 kernel are prepared for Oracle Linux 7 (there are no obstacles to using this kernel in similar versions of RHEL, CentOS and Scientific Linux).

Key improvements:

  • Improved support for 64-bit systems based on the ARM architecture. Updated drivers for ARM.
  • InfiniBand includes on-demand paging support, which allows you to reflect memory through a processor for accessing unallocated pages of memory (page faults), i.e. consume memory when it is actually being used.
  • In XFS, a deadlock was eliminated, which caused the locks to freeze and not free.
  • CIFS resolved an issue that could lead to POSIX lock leaks and crashes.
  • Bug fixes resolving issues with incompatibility of certain equipment with QEMU / KVM.
  • Device drivers are synchronized with the Linux kernel 4.14.35. The driver for Broadcom Emulex LightPulse Fiber Channel SCSI has been updated to version

Get more at the official blog