Red Hat Summit 2014 presentations

I went through some Red Hat Summit 2014 presentations and found few interesting things. Presentations are available at Red Hat website – https://www.redhat.com/summit/2014/presentations/.

Linux Containers in RHEL 7 – Key Takeways (Link to presentation)

  • Application isolation mechanism for Light-weight multi-tenancy
  • Application centric packaging w/ Docker image-based containers
  • Linux Containers Productization
    • Key kernel enablers – full support in RHEL 7 GA
    • Docker 1.0 – shipped with RHEL 7 GA
  • Linux Container Certification
  • Red Hat and Docker partnership to build enterprise grade Docker
    containers

RHEL roadmap (Link to presentation)

Theoretical Limits on X86_64

  • Logical CPU – maximum 5120 logical CPUs
  • Memory – maximum 64T

RHEL 7 will support XFS, ext4, 3, 2, NFS, and GFS2

  • Maximum supported filesystem sizes increase
    • XFS 100TB -> 500TB
    • ext4 16TB -> 50TB
  • btrfs is a technology preview feature in RHEL 7

Red Hat Enterprise Linux 7 has XFS as the new default file
system

  • XFS will be the default for boot, root and user data partitions on all
    supported architectures
  • Included without additional charge as part of RHEL 7 subscription

RHEL 7 Storage Enhancements

  • New protocols and driver support
    • Shipping NVMe driver for standard PCI-e SSD’s
    • Support for 16Gb/s FC and 12Gb/s SAS-3
    • Linux-IO SCSI Target (LIO)
    • User-specified action on SCSI events, e.g. LUN create/delete, thin provisioning threshold reached, parameter change.
  • LVM
    • RAID, thin provisioning and snapshot enhancements
    • Tiered storage, using LVM/DM cache, in technology preview

 Red Hat Enterprise Virtualization Hypervisor roadmap (Link to presentation)

Performance: Windows Guest Improvements

  • Make Windows guests think they are running on Hyper-V

Scalability: Large Guests

  • Host: 160 cores; 4TiB RAM
  • Virtual Machine CPU Limit : 160 vCPUs
  • RHEL6 4000GiB guest RAM
  • RHEL7 4 TiB guest RAM

Nutanix Controller VM console output under KVM

Recently I had a chance to be a part of setting up a Nutanix block (3 nodes). That block shipped with KVM hypervisor from the factory. Nutanix engineer was on site with us to do the first installation. Our first task was to replace the KVM with ESXi. We booted up all 3 nodes to do the re-imaging but for some reason only 2 nodes appeared on the management software. After some debugging we discovered that the Controller VM (CVM) on the 3-rd node was not working. There is a CVM console output file named NTNX* located in /tmp. From there we were able to see why the CVM was not booting up. For us the quickest way to fix the problem was to re-image the node manually with ESXi version.