Hello and thanks for your replies,
It's a Seagate Expansion Desktop 5TB (USB3). It is probably a
ST5000DM000.
this is TGMR not SMR disk:
TGMR is a derivative of giant magneto-resistance, and is what's been
used in hard disk drives for decades now. With limited exceptions in
recent years and in ancient embedded systems, all modern hard drives are
TGMR based.
Ok, thanks; So, TGMR does not say whether or not the Device is SMR or
not, right?
While the Data-Sheet does not mention SMR and the 'Desktop' in the name
rather than 'Archive' would indicate no SMR, some reviews indicate SMR
(http://www.legitreviews.com/seagate-barracuda-st5000dm000-5tb-desktop-hard-drive-review_161241)
In any case: the drive behaves like a SMR drive: I ran a benchmark on it
with up to 200MB/s.
When copying a file onto the drive in parallel the rate in the benchmark
dropped to 7MB/s, while that particular file was copied at 40MB/s.
This type of performance degradation is actually not unexpected
Ok. I was not aware. I expected some, but less impact.
There's two things that should be clarified here:
[...]
Thanks for clarifying.
Well, I'm no pro. But I found this:
https://github.com/kdave/drafts/blob/master/btrfs/smr-mode.txt
And this does sound like improvements to BTRFS can be done for SMR in a
generic, not vendor/device specific manner.
And I am wondering:
[...]
b) whether these improvements have been made already
Not yet.
Ok, thanks.
So I conclude that on SMR Drives, BTRFS has all benefits that it has on
all other devices and there are no BTRFS related disadvantages in
relation with BTRFS. Nevertheless, some improvements to BTRFS can be
made in order to improve BTRFS with these drives.
Greetings,
Hendrik
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