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kudos & congrats on efficiency.

DISCUSSION L A Walsh 1 participant 1 message May 26, 2017

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L A Walsh

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I tend to be a bit of a performance-geek -- often running various self-relevant benchmarks to see how long things take and working on optimizing configs for speed & efficiency.

I wanted to backup a 45.5GB dir (with 260 subdirs, & 633 files) from my Win7SP1 PC to my home server. I frequently have the Win7 disk (SSD-based) mounted on a top-level dir.

An aside, I want to repeat a kudo relating to win-symlinks appearing as linux-native symlinks via CIFS. That's excellent. It may have just 'fallen out' from other work, but it's still very cool.

Second is on efficiency, uncovered by running tar. I thought
the 45G would take a few-several minutes to xfer even with my 8Gb (says
10, but get a 20% penalty for having an older PCIe bus) ethernet.
It took < 2 minutes to write to a tar file. I ran the tar again
(after dropping local caches) w/output to /dev/null...
took 82.02s : average 568MB/s! With CIFS taking 70-80% cpu.
A rerun on the server after another dropcache, averaged 687MB/s. Maybe subsequent runs benefit from the win7-cache. Not sure how to readily drop the Win7 cache (other than alloc'ing
all mem in the machine and forcing the cache to be dumped)...

Anyway, for comparison, my current version of samba gives ~450MB/s for reads and ~200MB/s for writes.

Congrats!
-Linda W.