Pass the EMC EMC Certification E20-598 Questions and answers with CertsForce

Explanation/Reference:

Explanation/Reference:

Server maintenance activity monitoring

Avamar performs the system maintenance operations for backup data on the Data Domain system, includingHFS checks, checkpoints, rollbacks, garbage collection, and secure backup deletion.

The ddmaint utility implements all required operations on the Data Domain system for the Avamar server.The ddrmaint utility is installed on the utility node of a multi-node server, or the single node of a single-nodeserver, during Avamar server installation. The ddrmaint utility is not installed on the data nodes of the Avamarserver.

The ddrmaint utility logs all maintenance activities on the Avamar server in the ddrmaint.log file. Thefollowing directory on either the utility node of a multi-node server or the single node of a single-node servercontains the log file:

/usr/local/avamar/var/ddrmaintlogs/ddrmaint.log

The ddrmaint.log file is rotated when it reaches 25 MB in size.

Explanation/Reference:

Explanation/Reference:

Capacity Threshold Warnings:

80% of user capacity = warning, start planning for expansion or cleanup

95% user capacity is the health check warning, new backups are suspended

100% user capacity makes the Avamar read-only, can still restore from server

85% of OS capacity = Garbage collection stops running, utilization increases rapidly

90% OS capacity = HFS checks stop running

96% OS capacity = no more checkpoints

Explanation/Reference:

Capacity Threshold Warnings:

80% of user capacity = warning, start planning for expansion or cleanup

95% user capacity is the health check warning, new backups are suspended

100% user capacity makes the Avamar read-only, can still restore from server

85% of OS capacity = Garbage collection stops running, utilization increases rapidly

90% OS capacity = HFS checks stop running

96% OS capacity = no more checkpoints

Explanation/Reference:

vamar, has a rather nifty technology called Sticky Byte Factoring which allows it to identify the changedinformation inside a file by breaking the file into variable length objects, this leads to much greater efficiencythan fixed size approaches as changes made early in a fixed length sequence affect all subsequent blocks/chunks/objects/whatever in that sequence. This in turn changes all the fingerprints taken following the changeddata which means you end up with a lot of new blocks/chunks/objects/whatever even if the data really hasn'tchanged all that much. Sticky Byte Factoring on the other hand can tell what exactly has changed, not just thatthings have changed.