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trevorjharris

Slow backing up 7tb

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I have Retrospect for Windows installed on an HP z800 workstation running windows 7 sp1 64bit. I have dual Xeon X5660 which has 6 cpus each with hyperthreading and 48GB of memory. I am copying from an 8TB raid array which has a speed of 635 GB/s reading 4k sequential according to crystalmark 5. I am backing up to an 8TB seagate usb 3 drive capable of writing 170 GB/s 4k sequential.

I backed up 7098.3 GB at 2263 MB/min which took 2 days 6h and 33 mins.That is about 38 MB/sec which seems very slow.

Is there any way of optimising Retrospect with respect of writing to drives.

Regards Trevor

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Is this a backup of the files on the array to a backup set on the 8TB USB3 disk or is it a duplication of the files from the array to the disk?

How many files are you trying to backup off the RAID array and what is their average size? Generally a small number of large files will backup faster than a large number of small files.

What RAID level (RAID1, RAID5, RAID6, etc) is the array using? Is the array internal or external to the HP z800 running Retrospect? Is the performance you quote for the RAID array what you have measured or what the manufacturer is quoting? 

The specification for USB 3 states maximum throughput of 5 gigabits/second or 625 megabytes/second. This no where near what you are quoting for the USB 3 connected 8TB Seagate drive.

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trevorjharris should read this thread, even though it is about Retrospect Macintosh, especially the third post—which relates my experience backing up drives that are local to my "backup server".  As he will note, my backup speed on the first local drive is very similar to what he is complaining about.

P.S.: trevorjharris should also read the first two paragraphs of the second post in that thread, which attempts to explain the speed-limiting factor for Retrospect backups.  Scillonian's second paragraph in the second post in this thread implicitly agrees with that explanation.  trevorjharris should also review the convention for writing "bits" vs. "bytes"; a lower-case 'b' means "bits" and an upper-case 'B' means "bytes".

Edited by DavidHertzberg
Added P.S. urging reading of another post in the linked-to thread, and suggesting reading of the convention for writing "bits" vs. "bytes"

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