Contains build configuration for the µCernVM Linux kernel and busybox.
The CernVM Kernel is a virtualization friendly Linux kernel. It is intended to be used by a CernVM guest OS. In contrast to an (S)LC kernel, it is lightweight and provides the newest features wrt virtualization and memory management techniques.
Features:
- Based on vanilla sources
- (Paravirtualized) device drivers for KVM, Xen, VMware, VirtualBox, and HyperV
- Boots an SL6 OS and possibly other distributions
- Provides the following options
- X32 ABI support
- Kernel SamePage Merging (KSM)
- Transparent Huge Pages (THP)
- zRam, zCache, cleancache, frontswap
- (All) cgroup controllers
- Aufs3 (patched from aufs upstream)
- ext2-4, XFS, Btrfs (module), NTFS (module), Fuse (module)
- Rados block device, CephFS (module)
- NFS 3, 4, 4.1
- LVM / device mapper
- OpenAFS (module, patched in by EC build system)
Kernel, Ramdisk, and modules are 10MB--20MB in size, compared to >100MB of SL6. After boot, it occupies ~25MB less memory than the SL6 kernel.
The busybox configuration is not primarily optimized for size but it is meant to provide a sufficiently comfortable environment to debug µCernVM
Kernel and busybox are built on Electric Commander.