Type: Evaluation Essays
Sample donated: Henry Norton
Last updated: December 31, 2019
This sectionpresents and compares VM migration op-timization schemes that considerbandwidth, DVFS-enabled power, and storage optimization to reduce the sideeffects of VM migration process.
VM migration through LAN abuses networkattached storage (NAS) architecture to share the storage between communicatingservers. But, migrating a VM across WAN boundaries requires migrating largesized storage in addition to VM memory over intermittent links A. Bandwidth optimization This section discusses effectively using of limited network capacity toenhance application performance during the VM migration process. It also showsa thematic taxonomy evaluation of existing schemes and comparisons betweenbandwidth optimization schemes.
1) Taxonomyof bandwidth optimization schemes: Different bandwidth optimization live VMmigration schemes result in varying application downtime and total migrationtime based on the nature of workload hosted within the migrant VM, type ofnetwork link, number of con-current migrant VMs, and type of hypervisorselected to manage server resources. The proposed scheme applies binaryXOR-based RLE (XBRLE) delta compression to improve VM migration performance.Prior to triggering migration, a guest kernel conveys soft page addresses tothe VMM. For further improvement, the delta page is compressed using a lightweight compression algorithm.
2) Reviewof bandwidth optimization schemes: An opti-mized post-copy VM migration schemewas proposed that exploits on-demand paging, active push, pre-paging, anddynamic self-ballooning optimizations to pre-fetch memory pages at the receiverhost. Besides, growing bubbles around the pivot memory page to transferneighboring memory pages does not always improve VM migration performance,especially when write-intensive applications are hosted within migrated VMs.Active push transfers memory pages to the target server and ensures that everypage is sent exactly once from the source server. This scheme progresses bytransferring CPU registers and device states to the receiver host prior to VMmemory content migration.
3) Comparisonof bandwidth optimization schemes: Many VM migration approaches have optimizedapplication down-time and total migration duration by employing optimizationand avoiding aggressive migration termi-nation a case of pre-copy. Moreover, anoptimization method presents additional overhead on shared resources like CPU,memory, or cachewhile optimizing VMmigration performance parameters such as downtime, total migra-tion time, andapplication QoS. illustrates a qualitative comparison of VM migration schemesbased on selected parameters to highlight commonalities and variances inexisting bandwidth optimization schemes. Live VM migration schemes followeither pre-copy post-copy, or hybrid migration patterns to migrate VMs acrossservers.