[SUMMARY] backup server bootleneck

Answers to my questions:

a) Is the PCI slot a bottleneck? What is the sustained traffic that a slot
like that support?

Most people said NO.

Doug Bell described how to calculate the PCI Bus bandwidth:

"If you want real numbers, you can do the math to get really close..  64 bits
X
66MHz / 8 bits per byte X 0.6 (back of the envelope modifier for overhead) =
316,800,000 bytes per second"

Some others have not pointed out the overhead, though.


b) Is the SCSI host adapter a bottleneck? Again, how many MB/s can pass
through each port?

This depennds on the specific card. ULtra 3 cards can support 320 MB/s.


Some people pointed out some likely bottlenecks:

a) network interface
b) clients with many small files

Thank you very much.




>Hi
>
>I4m using a V480 as a backup server (Veritas Netbackup).
>
>Th server has a PCI Dual Ultra3 SCSI Host Adapter (LVD) connected to
>a 66 MHz PCI slot, which has two ports, and each port is connected
>to two drives.
>
>My concerns:
>
>a) Is the PCI slot a bottleneck? What is the sustained traffic that a slot
>like that support?
>
>b) Is the SCSI host adapter a bottleneck? Again, how many MB/s can pass
>through
>each port?
>
>I know that my drives have a theoretical capacity of 60 MB/s.
>
>Thanks
>_______________________________________________
>sunmanagers mailing list
>sunmanagers@sunmanagers.org
>http://www.sunmanagers.org/mailman/listinfo/sunmanagers
>
>

--
__________________________________________________________________

Scott Lawson
Unix Systems Architect
Manukau Institute of Technology
Information Communication Technology Services
Private Bag 94006
Manukau City

Phone  : +64 09 968 7611
Fax    : +64 09 968 7641
Mobile : +64 27 568 7611

mailto:scott@manukau.ac.nz

http://www.manukau.ac.nz

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