On Sat, Jul 7, 2012 at 6:26 PM, Todd And Margo Chester
<[log in to unmask]> wrote:
> On 07/07/2012 01:38 PM, Todd And Margo Chester wrote:

> Here is the report from the end of a backup I just finished -- includes
> and entire backup  (not incremental), compression and decryption:
>
>   DUMP: Volume 1 took 1:21:16
>   DUMP: Volume 1 transfer rate: 47271 kB/s
>   DUMP: Volume 1 288102550kB uncompressed, 230493747kB compressed, 1.250:1
>   DUMP: 288102550 blocks (281350.15MB) on 1 volume(s)
>   DUMP: finished in 4876 seconds, throughput 59085 kBytes/sec
>   DUMP: Date of this level 0 dump: Sat Jul  7 13:51:23 2012
>   DUMP: Date this dump completed:  Sat Jul  7 15:12:44 2012
>   DUMP: Average transfer rate: 47271 kB/s

So, as raw data, 42 MBytes/second. That's pretty good, I assume you
have some nice local hardware to write to. The compression is only
1.250 to 1, so let's basically ignore it. You probably no not need it,
unless your backup media is near its space limit, and I suspec you're
near the limits of your hardware.

Rsync won't buy you that much with transferring files that are updated
disk images, unless they're unmodified: you've still got to read them
from the file system. Writing bulky material from one drive to another
approaches the limiting speed of the hardware. My last, somewhat
artificial test approached 80 MBytes/second, but it was transferring
single bulky files on some pretty hot hardware.

For tar and star, it's been a while since I did bulky transfers local
transfers. From years ago, it was similar to rsync in oveall transfer
speeds. But all three of them can do *incremental* updates, and not
transmit material already successfully transferred. So can dump with
"level 1 through 9" instead of level 0 backups, but it's more awkward
to recover the data.

>   DUMP: Wrote 288102550kB uncompressed, 230493747kB compressed, 1.250:1
>   DUMP: DUMP IS DONE

I assume that the majority of that transfer is the disk images from
KVM? This makes me wonder if your XP image is one of those
"dynamically sized" images, and when the XP is running it's changing
the image's filesize or chattering to the disk.