Il 15-11-2017 21:17 Gionatan Danti ha scritto:
Il 15-11-2017 20:47 Christoph Hellwig ha scritto:
And in that case it will report WCE=0 and Linux won't even flush.
As is the case for typical enterprise disks.
Good point. Based on what I read here[1], page n.4, it *seems* that
Seagate AWC (advanced write cache) enabled drives report WCD (write
cache disabled) to the host OS.
I think this is the key parameter to watch: if the HDD vendor is
confident enough to report WCE=0/WCD, than it should be safe running
without barriers (after all, in this case Linux *will* disable barrier
by default).
Thank you Christoph for pointing that.
Regards.
Sorry, I forgot the link:
https://www.seagate.com/files/www-content/product-content/enterprise-performance-savvio-fam/enterprise-performance-15k-hdd/_cross-product/_shared/doc/enchanced-cache-advantage-tp691.1-1610us.pdf
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