1 / 11

PERGAMUM: REPLACING TAPE WITH ENERGY EFFICIENT, RELIABLE, DISK-BASED ARCHIVAL STORAGE

PERGAMUM: REPLACING TAPE WITH ENERGY EFFICIENT, RELIABLE, DISK-BASED ARCHIVAL STORAGE. M. W. Storer K. M. Greenan E. L. Miller UCSC K. Vorugant Network Appliance. Summary. These slides only include what is missing in the Shockwave presentation: Background on MAID Glossary

fauve
Télécharger la présentation

PERGAMUM: REPLACING TAPE WITH ENERGY EFFICIENT, RELIABLE, DISK-BASED ARCHIVAL STORAGE

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. PERGAMUM: REPLACING TAPE WITH ENERGY EFFICIENT, RELIABLE,DISK-BASED ARCHIVAL STORAGE M. W. Storer K. M. Greenan E. L. MillerUCSC K. VorugantNetwork Appliance

  2. Summary • These slides only include what is missing in the Shockwave presentation: • Background on MAID • Glossary • Two-level redundancy • Digital signatures • They are not self-sufficient

  3. MAID • Massive Array of Idle Disks • Designed for Write Once, Read Occasionally applications. • Each disk is only spun up when a request is issued for the data on disk • Problems: • Less redundancy than RAID arrays • Frequent spin ups wear disks

  4. Glossary (I) • Tome: • Basic hardware unit • Consists of • A low-power CPU with DRAM • A commodity SATA drive • A small flash drive • An Ethernet connection • Very autonomous

  5. Glossary (II) • Blocks: • Much larger than conventional disk blocks • 128 KB to 1 MB • Will batch up small files into large files for archival storage • Normally done for tape drives (tar)

  6. Glossary (III) • Segments: • Consist of a fixed number of blocks • Intra-disk parity is computed inside each segment • Includes one or two parity blocks

  7. Glossary (II) • Regions: • Formed by a given number of segments • Basic building block for inter-disk redundancy

  8. Two-level redundancy

  9. Intra-disk redundancy • Used to fix unrecoverable read errors (bad blocks) without spinning up disks of other tomes • Save energy • Reduce frequency of disk scrubbing operations • Can reconstitute contents of bad blocks

  10. Inter-disk redundancy • Used to recover from disk failures • Recovery process is designed to minimize peak power consumption rather than total power consumption

  11. Digital signatures • Include a timestamp (32 bits) • Stored in flash memory • Used to detect • Incorrect propagation of updates • Write errors

More Related