Dell DX6004S DX Object Storage Administration Guide - Page 44

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39

Version 5.0

December 2010

6.4. Managing Other Stream Replication Settings

6.4.1. minreps, maxreps, and defreps

These options give an administrator the ability to control how many replicas of streams can be

created and maintained within a cluster. Since each individual stream can request a certain number

of replicas be created, these parameters allow the administrator to override those choices to

account for the characteristics of the cluster as a whole. The minreps option gives an administrator

the ability to globally set the minimum number of instances that any stream is allowed to have,

irrespective of its lifepoint specifications. This value is a floor and will override a lower value that

may be set by an application developer. If an application requests more instances than the minreps

value, the higher number requested by the application will be used. Similarly, the maxreps option

gives an administrator the ability to limit the requested number of replicas so that it cannot exceed

a certain value. For small clusters, maxreps could be set to the total number of nodes in the cluster,

thus preventing needless error messages when the cluster is unable to fully replicate streams

because there are too few nodes. The final option, defreps, allows the administrator to specify a

default number of replicas that is used only if an individual stream does not specify number of reps

in its lifepoints. As the names imply, maxreps should be at least as large as minreps and defreps

should fall between minreps and maxreps (inclusive).

6.4.2. hpStartDelay

The

hpStartDelay

option allows an administrator to control the delay before the health processor

begins checking the cluster for the required number of replicas for content stored on this node. This

delay window occurs once following the startup of a node and provides a grace period for other

nodes in the cluster to stabilize. This is useful in situations where an entire cluster must be shut

down and restarted.

The health processor helps maintain data integrity on the cluster by performing the following tasks:

•

Verifies the correct number of replicas exist in the cluster and makes sure replicas are properly

distributed on subclusters.

•

Enforces lifepoint policies (enforces replica counts and delete policies (terminal lifepoints

specifically) at different policy time intervals).

•

Validates the object's MD5 on the disk and creates a new replica if it doesn't match. This can

happen over time because of disk errors.

•

Periodically evaluates if an object is optimally stored in its current location.

•

Defragments storage space on an as needed basis.

6.5. Managing Volumes

The

vols

option in the node or cluster configuration file specifies the volumes that DX Storage

uses. This specification includes the device names and optional flags for handling these volumes.

Only one

vols

parameter is allowed in a configuration file.

Warning

DX Storage erases any non-DX Storage data on all the volumes it uses. Dell

recommends you run DX Storage only on nodes that are free of non-DX Storage data.

Section	Page
DX Object Storage Administration Guide	1
Table of Contents	3
Chapter 1. Welcome to DX Storage	6
1.1. Overview of DX Storage	6
1.2. Components	6
1.3. About this Document	6
1.3.1. Audience	6
1.3.2. Scope	6
Chapter 2. Introduction to the Admin Console	7
2.1. Accessing the Admin Console	7
2.2. Initial View of the Admin Console	7
2.2.1. Viewing the Cluster Status Page	7
2.2.2. Viewing a Node's Status Page	8
2.3. Printing the Admin Console	8
2.4. Viewing License Information	8
Chapter 3. Managing the Cluster	10
3.1. Viewing the Cluster Status Page	10
3.2. Authenticating Cluster-Wide Actions	11
3.3. Shutting Down or Restarting the Cluster	12
3.4. Viewing Nodes in the Cluster	12
3.5. Searching for Nodes By IP Address	13
3.6. Searching for Nodes by Status	13
3.7. Choosing and Preserving Cluster Settings	13
3.7.1. Enabling Logging	15
3.7.2. Replication	15
3.7.3. Suspend	15
3.7.4. Power	15
3.7.5. Managing Tenants	15
3.8. Cluster Name	15
3.9. Cluster Multicast Address	15
3.10. % Used Indicator	15
Chapter 4. Managing Tenants	17
4.1. Terminology Related to Tenant Security	18
4.2. About the Default Cluster Domain	19
4.3. Security Privileges for Administrative Operations	20
4.4. Rules and Recommendations for Managing Tenants	21
4.5. Domain Naming Rules	21
4.6. Adding, Editing, or Deleting Tenants	22
4.7. Other Cluster Administrator Tasks	24
4.7.1. Using Administrative Override	25
4.7.1.1. Using Override to Delete an Object	25
4.7.1.2. Using Override to GET or APPEND User Lists	25
4.7.1.3. Using Override to Resolve Authorization Specification Issues	27
4.7.2. Working With Inaccessible Objects	28
Chapter 5. Managing Nodes	30
5.1. Viewing the Node Status Page	30
5.1.1. Shutting Down or Restarting a Node	30
5.1.2. Retiring or Identifying a Node	30
5.1.2.1. Retiring a Node or Volume	30
5.1.2.2. Identifying a Volume	31
5.1.3. Errors and Announcements	31
5.1.4. Additional Node Status Information	31
5.1.4.1. Hardware Status Reporting	33
5.2. Displaying Subcluster Information	34
Chapter 6. Configuring the Node	35
6.1. Option Names and Descriptions	35
6.2. Managing DX Storage Administrators and Users	41
6.2.1. Defining CAStor administrators and SNMP Administrators	41
6.2.2. Defining DX Storage Operators	42
6.2.3. Securing the Administrator and Operator Passwords	42
6.3. Managing Content Integrity Settings	43
6.3.1. autoRepOnWrite	43
6.3.2. repPriority	43
6.3.3. autoValidateRead	43
6.4. Managing Other Stream Replication Settings	44
6.4.1. minreps, maxreps, and defreps	44
6.4.2. hpStartDelay	44
6.5. Managing Volumes	44
6.5.1. device	45
6.5.2. policy	46
6.5.3. Specifying Exceptions	46
6.6. Configuring Power Management Settings	46
6.6.1. sleepAfter	46
6.6.2. wakeAfter	46
6.7. Managing Other Settings	46
6.7.1. consolePort	46
6.7.2. domainHeaders	46
6.7.3. loghost	47
6.7.4. timeSource	47
Chapter 7. Managing Volumes	49
7.1. Volume Expiration	49
7.2. Movement Between Nodes	49
7.3. Physical Errors	49
Appendix A. Implementation of Multi-Server Chassis	51
A.1. Configuration Parameters	51
A.1.1. Processes parameter	51
A.1.2. Network Setup parameters	51
A.1.3. Using the vols parameter	52
A.1.4. Using the subcluster parameter	52
A.2. Monitoring and Administration	53
Appendix B. Using SNMP with DX Storage	54
B.1. SNMP Management Information Base (MIB) Reference	54
B.2. Managing DX Storage Nodes	54
B.2.1. Shutdown Action for Nodes	54
B.2.2. Retire Action for Nodes and Volumes	54
B.2.2.1. Single Volumes	55
B.2.2.2. Entire Node	55
B.3. SNMP Tools and Monitoring Systems	55
B.3.1. Open Source Tools	55
B.3.2. SNMP Examples with DX Storage	56
B.3.3. SNMP Action OIDs	56
B.3.3.1. castorShutdownAction	56
B.3.3.2. castorRetireAction	56
B.3.3.3. castorLogLevelAction	56
B.3.3.4. castorSyslogHostAction	56
B.3.3.5. volumeRecoverySuspend	57
B.3.4. Practical SNMP with DX Storage	57
B.3.4.1. Health Monitoring	57
B.3.4.2. Capacity Monitoring	57
B.3.4.3. Client Activity Reporting	58
Appendix C. Upgrading a License or Cluster	59
C.1. Upgrading a License File	59
C.2. Software Upgrade Overview	59
C.2.1. Preparation	59
C.2.2. Upgrade Steps	60
C.2.2.1. Example Shutdown Script	60
C.2.2.2. Cluster Reboot	60
C.3. Back-out Steps	61
Appendix D. Troubleshooting	62
D.1. Restoring Domains and Buckets	62
D.1.1. Recovering a Deleted Domain	62
D.1.2. Recovering a Deleted Bucket	65
D.2. Resolving Duplicate Domain Names in a Mirrored or Disaster Recovery (DR) Cluster	66
D.2.1. Renaming a Domain in its Source Cluster (DR Cluster Conflict Only)	66
D.2.2. Renaming a Domain in a Mirrored or DR Cluster	67
D.3. Using DX Content Router to List Buckets and Objects	69
D.4. Boot Errors	69
D.5. Configuration	70
D.6. Operational Problems	70
Appendix E. Drive Identification API	72
E.1. Overview	72
E.2. Customization Steps	72
Appendix F. Customizing the Admin Console	73

Dell DX6004S DX Object Storage Administration Guide - Page 44

Managing Other Stream Replication Settings, 6.4.1. minreps, maxreps, and defreps

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