Is there anyone out there who backs up a filer directly to DLT via NDMP? I've seen a demo of an F740 backing up directly to a DLT 7000 and the throughput peaked at around 8MB/sec. I'd like to know actual vs. theoretical throughput for the same configuration, but with a DLT 4000.
Thanks, Dianna
Is there anyone out there who backs up a filer directly to DLT via NDMP? I've seen a demo of an F740 backing up directly to a DLT 7000 and the throughput peaked at around 8MB/sec. I'd like to know actual vs. theoretical throughput for the same configuration, but with a DLT 4000.
Not really a netapp specific thing. A DLT7000 can sustain 5MB * compression ratio. So 2:1 could get you near 10MB/s. That jibes well with your observations.
A DLT4000 is supposedly rated at 1.5MB * compression ratio, so I'd expect somewhere around 3MB/s with compressible data.
Any netapp/network/application issues can only drag that value lower, not speed it up.
Can two F740s be clustered if one filer has FC9 shelves and one filer has FC8 shelves? The examples in the "F740 and F760 Cluster Guide" suggest not, but I don't see a definitive no (or yes) there...
I back up a 740 to a DLT 7000 via fiber channel. I regularly see 8-12MB/sec rates with lows of 4 and high's of 14. no idea why the peaks and valleys as this filer is very steady in it's traffic.
~JK
Dianna Mullet wrote:
Is there anyone out there who backs up a filer directly to DLT via NDMP? I've seen a demo of an F740 backing up directly to a DLT 7000 and the throughput peaked at around 8MB/sec. I'd like to know actual vs. theoretical throughput for the same configuration, but with a DLT 4000.
Thanks, Dianna
The rates at which it will write to tape are dependent on many factors, one of which being the layout of the filsystems on the volume you are backing up.
If you have a large volume that has a lot of subdirectories and little files, your write rates will go down a bit while the NDMP backup reads that data then writes. If you have filesystems of large blocks of data (like a logs directory or a lot of compressible data files), then you can see nice speeds.
I backup several 200-350Gb fileystems, and see tape writes run between 1-8Mbps. When I see the higher rates, it's almost always churning on some logs directories....
-Scott
On Mon, 9 Apr 2001, Jeff Kennedy wrote:
I back up a 740 to a DLT 7000 via fiber channel. I regularly see 8-12MB/sec rates with lows of 4 and high's of 14. no idea why the peaks and valleys as this filer is very steady in it's traffic.
~JK
Dianna Mullet wrote:
Is there anyone out there who backs up a filer directly to DLT via NDMP? I've seen a demo of an F740 backing up directly to a DLT 7000 and the throughput peaked at around 8MB/sec. I'd like to know actual vs. theoretical throughput for the same configuration, but with a DLT 4000.
Thanks, Dianna
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Jeff Kennedy Unix Administrator AMCC jlkennedy@amcc.com
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