1 / 68

HP OpenVMS Volume Shadowing in Action

Shadowing Performance. Shadowing is primarily an availability tool, but:Shadowing can often improve performance (e.g. reads), however:Shadowing can often decrease performance (e.g. writes, and during merges and copies). Shadow Copy/Merge Performance: Why Does It Matter?. Excessive shadow-copy time

aelwen
Download Presentation

HP OpenVMS Volume Shadowing in Action

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

    1. Keith Parris Systems/Software Engineer, HP Session 1546 HP OpenVMS Volume Shadowing in Action

    2. Shadowing Performance Shadowing is primarily an availability tool, but: Shadowing can often improve performance (e.g. reads), however: Shadowing can often decrease performance (e.g. writes, and during merges and copies)

    3. Shadow Copy/Merge Performance: Why Does It Matter? Excessive shadow-copy time increases Mean Time To Repair (MTTR) after a disk failure, or a site outage in a disaster-tolerant cluster Shadow Full Merges can have a significant adverse effect on application performance Shadow copies or merges can generate a high data rate (e.g. on inter-site links for Disaster Tolerant clusters) Acceptable shadow full-copy times and link costs are often the major factors in selecting inter-site link(s) for multi-site disaster-tolerant clusters Shadow Full-Copies can also take a high amount of CPU time in interrupt state with EVAsShadow Full-Copies can also take a high amount of CPU time in interrupt state with EVAs

    4. Shadowset State Hierarchy Mini-Merge state Copy state Mini-Copy state Transient states Full Copy state Full Merge state Steady state

More Related