Gentoo Archives: gentoo-user

From: Wol <antlists@××××××××××××.uk>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] External hard drive and idle activity
Date: Fri, 03 Jan 2020 00:43:12
Message-Id: f364e3aa-44ba-c99c-2d67-ac09eab2509f@youngman.org.uk
In Reply to: Re: [gentoo-user] External hard drive and idle activity by Rich Freeman
On 02/01/2020 19:12, Rich Freeman wrote:
> For reads they're completely normal. For sequential writes to unused > space they're completely normal. For random writes or overwrites they > are significantly different from traditional hard drives.
That's why the "S" stands for "shingled" (which means "overlapped", think of a shingled roof - which is your normal overlapping tile jobbie). The point of a shingled drive is that it has a narrow read head - let's call it one unit wide. But a write head is larger, lets call it three units wide. If each track is one unit wide - the correct size to be read - then writing a track will destroy two tracks. So the write head lays down data in concentric rings, and CAN'T overwrite data - it has to wipe everything and rewrite it. So as mentioned before you really do not want these drives for random writes - think of them as a bit like a random-write tape drive ie you can get away with it but you're better off not trying. And yes - the 8TB capacity gave it away - I think the largest "normal" drives available are 4TB at present ... anything bigger must be shingled. Cheers, Wol

Replies

Subject Author
Re: [gentoo-user] External hard drive and idle activity Rich Freeman <rich0@g.o>