Справочник Пользователя для Iomega tapeware

 

You control the data streams of a volume, directory or file from its Storage tab. 
Normally, the Backup stream field on the Storage tab of a volume is set to Create new 
stream, while the Backup stream of a directory or file is set to Use existing stream. By 
changing these options, you can change the number of backup streams, thereby affecting 
the speed at which the job runs. Assigning the proper number of data streams can help 
speed up the data transmission rate. 

In general, you should assign data streams according to the number of streams the 
physical device (e.g., the disk drive) is capable of handling. Usually this number is equal 
to the number of spindles the drive has. Under most circumstances, you should use this 
number to determine the number of data streams. 

One exception to this general rule is when you are working with very large files. You can 
increase performance by creating an additional stream for each of these very large files. 
For example, if you have a very large file with 1.0 GB or more, create a separate stream 
for this file. Then TapeWare will be able to send the file to the tape drive at a higher rate 
that allows for “streaming.” 

Consider these three examples: 

1.  A RAID device is capable of sustaining multiple data streams at once. By assigning 

various directories on the RAID device to additional streams, you can increase the 
rate of data transmission. To do so, assign large directories to their own streams by 
changing the Backup stream field of each directory’s Storage tab to Create new 
stream. Don’t add any more streams than the RAID device can sustain. 

 

Use the Storage tab to 

create new streams for 

large files and directories 

on RAID devices. 

 

2.  On the other hand, a single physical device may have multiple logical volumes. If 

each volume is assigned a separate stream, this will not result in faster data 
transmission and may, in fact, result in slower data transmission if it creates 
additional seeks by the disk drive. To turn off one of the data streams, change the 
Backup stream field on the volume’s Storage tab to Use existing stream. 

3.  Some file servers may have large database files on them, perhaps 1.0 GB or larger. 

These files should be assigned to their own streams. To do so, change the Backup 
stream field on the file’s Storage tab to Create new stream. 

In general, when creating or modifying data streams, first use the capacity of the physical 
device to determine the optimum number of data streams and then create separate streams 
for very large files. Too few or too many data streams will impede maximum 
performance.