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Speed issues with v6.1


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Hi, we are running the v6.1 on a G5/1.6Ghz tower that is connected to a Jetstor 416F via fiber (2Gbps).

 

The Tape library is a Quantum Superloader 3 with a Certance H3 LTO3 drive.

The SCSI card is an ATTO UL4D 320MBps.

 

We are trying to get the best performance out of this setup and have only reached a maximum of 800MB/min. We have tried setting the sync rate on the ATTO card to all of the possible settings with no improvement.

 

Before you tell me that 800MB/min is good, that translates to less than 15MB per second, which is not. Even if we were to get 1GB/min, that puts the completion at 83 hours. Not very useful if I can't even complete a full backup over the weekend and run differentials nightly.

 

Any insight?

 

Thanks in advance!

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The Jetstor's total capacity is 5TB, so we are plamming this solution for when we must back-up the whole thing. Currently it is about a 2.5TB of data.

 

Copy speed from the Jetstor to the internal drive is about 55MB/sec, which is limited by the write speed.

 

J

 

ps-Any idea as to what speed I should be getting to the tape library?

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Copy speed from the Jetstor to the internal drive is about 55MB/sec, which is limited by the write speed.

 


Hi.

 

And what if you create a file backup set on the internal hard drive and let Retrospect run for a while?

 

The drive vendors claim UP TO 80MB/s. That's in theory, not practice...

 

Regards

Lennart

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Ah, the backing up of the internal drive is about 15MB/sec. I will test backing up TO the internal and report.

 


Hi.

 

OK, it seems as the bottleneck is from the Mac to the tape station, not from the Jetstor to the Mac.

Are you sure you use the latest SCSI card firmware AND drivers?

Any other SCSI devices attached?

 

Regards

Lennart

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Hey all,

I've been reading this thread with some interest as I also am backing up a lot of data and it's taking a long time.

So, just for fun, I decided to run a test to see what kind of performance I'd get out of retrospect without the tape drive.

I've got a G5 with two Xraids attached, 7GB of RAM and the latest (or almost) of retrospect. I created a backup folder on one Xraid and then backed up two user's home directories from the other Xraid.

The end result was that user1 w/ 161 GB took 50 minutes and user2 with 142 GB took 73 minutes. I stripped out the idle time so this is "actual" backup time. I had an average throughput of 2507 MB/min. Not great really but probably on the better side of what can be expected. At this rate, 2TB of data would take around 14 hours or so to backup(feel free to check my math).

For even more fun, I did a plain copy of the above files between the two xraids and it took 90 minutes; thirty minutes less meaning that retrospect added 30 minutes or so to the time or 30-ish %.

 

for what it's worth.

 

-Mark

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That would mirror what we are seeing. Retrospect efficiency is just very low and might not be the best solution for backing up this amount of data. We were able to tweak the SCSI connection and change how we connected to the Jetstor to yield 1800MB/min. At that rate, we might be better off going to a hard disk backup and using a different utility to move the data as a copy.

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The end result was that user1 w/ 161 GB took 50 minutes and user2 with 142 GB took 73 minutes.

 


One thing to remember is that backup rates vary significantly with the file size/numbers involved. I used to use an XServe G5 (1.8G, 2G RAM) at my last job and could see the difference quite clearly between copying the thousands of small files that make up the OS on an OS X client, and backing up a few large files that the design dept create - this was generally across a 100Mbps network.

There is a fair overhead in maintaining the catalogue etc, this being the price you pay for the features.

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