AFS Cell Management Tools and Techniques Russ Allbery June 13, - - PowerPoint PPT Presentation

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AFS Cell Management Tools and Techniques Russ Allbery June 13, - - PowerPoint PPT Presentation

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Stanford University July 26, 2014 1 AFS Cell Management Tools and Techniques Russ Allbery June 13, 2005 Russ Allbery (rra@stanford.edu) Stanford University July 26, 2014 2 Introduction Stanford has 3.9TB of data in AFS, in 57,485

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Stanford University July 26, 2014 1

AFS Cell Management

Tools and Techniques

Russ Allbery June 13, 2005

Russ Allbery (rra@stanford.edu)

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Stanford University July 26, 2014 2

Introduction

  • Stanford has 3.9TB of data in AFS, in 57,485 volumes (as of June 1st).

(1.6TB user home directories, 660GB data, 180GB groups and departments, 550GB classes).

  • Administration when no migrations are in progress takes a few hours a week,

mostly creating unusual volumes, moving volumes around, and upgrading servers.

  • Tools presented here developed by Neil Crellin.
  • http://www.eyrie.org/˜eagle/software/
  • http://www.eyrie.org/˜eagle/notes/afs/

Russ Allbery (rra@stanford.edu)

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Stanford University July 26, 2014 3

Contents

  • Volume creation and management
  • Managing ACLs
  • Analysis and reporting
  • Replicated volumes
  • Monitoring with Nagios

Russ Allbery (rra@stanford.edu)

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Stanford University July 26, 2014 4

Creating Volumes

  • volcreate wrapper to balance where volumes are placed
  • Mapping volume types to servers
  • Size policy (2-4GB max for ease of moving volumes)
  • Automated log volume creation with volcreate-logs
  • Wrapper scripts for volume types (create-user, etc.)

Russ Allbery (rra@stanford.edu)

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Stanford University July 26, 2014 5

Managing Volumes

  • partinfo wrapper for usage information
  • mvto utility for all volume moving
  • Generating volume lists with vos listvol
  • Checking for unreleased volumes with unreleased
  • Balacing: why or why not, and possible overkill solutions
  • volnuke wrapper to delete volumes
  • Delegated volume creation ability (remctl and afs-backend)

Russ Allbery (rra@stanford.edu)

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Stanford University July 26, 2014 6

Managing ACLs

  • One PTS group per course, department, or group volume
  • Help desk tools to change PTS group membership (and volume quota)
  • fsr wrapper for users
  • Be careful of IP-based ACLs: subnets work best, better to use kstart and

machine srvtabs over IP ACLs

  • Log volume ACLS (lik) and the potential problems
  • Think about fs cleanacl
  • Unix directory owners and their special ACLs

Russ Allbery (rra@stanford.edu)

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Stanford University July 26, 2014 7

Tracking Volumes

  • Hierarchical naming scheme for volumes
  • Mount point database (mtpt, loadmtpt, cleanmtpts)
  • Nightly load into an Oracle database
  • Nightly reports from the Oracle database (released volumes, high accesses,

volumes moved, unreleased changes, missing mount points)

  • Monthly usage reports

Russ Allbery (rra@stanford.edu)

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Stanford University July 26, 2014 8

Replicated Volumes

  • Replication helps when server is down, not when it’s slow
  • How many replicas do you want? (2-4)
  • volcreate and server geographic locations
  • How RW and RO paths work: replicate the whole path
  • Delegated volume release ability (remctl and afs-backend)
  • frak to find changes
  • Restoring a RW from a RO with vos dump and vos restore

Russ Allbery (rra@stanford.edu)

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Stanford University July 26, 2014 9

Monitoring with Nagios

  • Basic tool: bos status
  • Monitor VLDB servers with udebug:

pt 7002, vl 7003, ka 7004

  • Available disk with vos partinfo
  • Connections waiting for thread (rxdebug)
  • AFS logs and kill -TSTP
  • Nightly problem reports from Oracle database

Russ Allbery (rra@stanford.edu)