How to define the Backup Speed

It is difficult to calculate backup speed. Disk layout, raid type etc. is one factor but other than that factors like availability of server resources, type of backup device, throughput supported by the backup device etc. are also very important.

From the link point oif view also, backup speed is dependendent on the available bandwidth. Generally, a 100 MB link on LTO-3 drives gives 15-18 Mbps and on GigE goes to 45-50 Mbps also. Performance also gets affected by the parallelism and target sessions set for the backups.

I had this same question a few months back, I'm cold on this so my answer may not be of help.

SAN: it depends on the type of drive, RAID group, how busy is the RAID group, how busy are the SPs if is a clarrion. one simple test you can do if you don't need to get in to much detail is to copy data from one LUN to another and see how much does it take...

Check the documents on powerlink you may get a better Idea of how to calculate a SAN backup speed.

NAS: just like the SAN it depends, but here you mostly depend on the network bandwidth, I made a replication calculation once, I simple checked how many kbps were being transmitted and did some conversion and I got my answer it was not 100% accurate but was close enough.

if I remember correctly it was something like: convert the size of the file system to kb and divide that by your transfer speed and that by 3600 to get the amount in hrs. I think...

I had to do  the conversion to kbps but you can go with kb/s it depends on how are you able to see your transmission speed.

1 kilobits = 0.125 kilobytes

example:

if you need to move 10GB over a powerfull 100kb/s link

Convert 10GB  to KB = 10485760

10485760 Kb / 100Kb = 104857.6Kb

104857.6Kb / 3600s = 29.127Hrs

to make it simple check this site: http://www.convert-me.com/en/convert/data_transfer_rate

Jiju wrote: Dear all,    Can anybody describe how the backup speed calculated in the Network and in the SAN environment . Its urgent please . Rajesh S

It's calculated based on data given by nsrmmd (or maybe it is calculated by nsrmmd itself).  As to how it is determined and what factors might impact it, see previous emails.