This articles applies to NetApp FAS, 7-mode and cDOT, and CommVault
What is file history and how is it communicated?
File history is generated during an Network Data Management Protocol (NDMP) backup of a volume hosted on NetApp storage using the dump engine. File history enables a Data Management Application (DMA) to build an index database over all the files in a backup. This database enables users to locate which backup contains a particular file, when that file was modified, and other useful meta data.
File History feature provides two benefits:
1. Provide a human-readable user interface to backup data.
2. Provide a basis for Direct Access Recovery (DAR). DAR allows a DMA to access files / directories directly on tape without having to traverse the entire backup. This allows for quicker file and directory recovery operations.
During what PHASE does File History generation occurs?
File history generation occurs in phase 3 and 4 of the dump process
File History can also lead to slower backups in certain environments due to 'backup pressure' as known in the NetApp world.
In general, file history adds overhead to a NDMP backup. A backup will typically always run faster with file history disabled than a backup with full file history capabilities, even with no other performance issues. This is due to processing overhead required to generate, communicate, and ingest the additional data.
Three main causes for slow NDMP Backup with FILE HIST = T, turned on.
1. Lack of computing resource on DMA [Physical/VM] - DMA = Media Agent
2. Slow Disk performance of the Index Drive.
I would like to disable FILE HIST temporarily for NDMP backups with my CommVault DMA, how can I do so ?
It's simple, just add the following regkey to your DMA [Media Agent] server.
Please note: Tested on v10, but should work on v11 as well.
Under the 'NAS' key, create another key (not a value) named "BackupHostOptions":
HKEY_LOCAL_MACHINE\SOFTWARE\CommVault Systems\Galaxy\Instance001\NAS\BackupHostOptions
In that key add a string value having exactly the name of the NAS client and set it to HIST=N, as shown in the figure below.
What is file history and how is it communicated?
File history is generated during an Network Data Management Protocol (NDMP) backup of a volume hosted on NetApp storage using the dump engine. File history enables a Data Management Application (DMA) to build an index database over all the files in a backup. This database enables users to locate which backup contains a particular file, when that file was modified, and other useful meta data.
File History feature provides two benefits:
1. Provide a human-readable user interface to backup data.
2. Provide a basis for Direct Access Recovery (DAR). DAR allows a DMA to access files / directories directly on tape without having to traverse the entire backup. This allows for quicker file and directory recovery operations.
During what PHASE does File History generation occurs?
File history generation occurs in phase 3 and 4 of the dump process
File History can also lead to slower backups in certain environments due to 'backup pressure' as known in the NetApp world.
In general, file history adds overhead to a NDMP backup. A backup will typically always run faster with file history disabled than a backup with full file history capabilities, even with no other performance issues. This is due to processing overhead required to generate, communicate, and ingest the additional data.
Three main causes for slow NDMP Backup with FILE HIST = T, turned on.
1. Lack of computing resource on DMA [Physical/VM] - DMA = Media Agent
2. Slow Disk performance of the Index Drive.
TIPS:
Put Index Cache on SSD
Put Job results directory on SSD
<>:\Program Files\CommVault\Simpana\iDataAgent\JobResults
3. Slow/Lossy Network between DMA & NDMP Server.Put Index Cache on SSD
Put Job results directory on SSD
<>:\Program Files\CommVault\Simpana\iDataAgent\JobResults
I would like to disable FILE HIST temporarily for NDMP backups with my CommVault DMA, how can I do so ?
It's simple, just add the following regkey to your DMA [Media Agent] server.
Please note: Tested on v10, but should work on v11 as well.
Under the 'NAS' key, create another key (not a value) named "BackupHostOptions":
HKEY_LOCAL_MACHINE\SOFTWARE\CommVault Systems\Galaxy\Instance001\NAS\BackupHostOptions
In that key add a string value having exactly the name of the NAS client and set it to HIST=N, as shown in the figure below.
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