Il 15-11-2017 21:18 Gionatan Danti ha scritto:
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
Ok, it seems that for Seagate drives the real document to read is that
one[1]. Quoting:
"When WCE=0, Advanced provides NVC-protected write caching over the
portion of the DRAM used to coalesce writes. Write data only goes into
NVC when there is an unexpected power loss to the drive. The NVC has
90-day data retention. When WCE=1, a Advanced Caching drive will operate
on writes like a standard drive–writes in cache are not protected by NVC
and may be lost with power loss."
In short:
- WCE=1 -> entire cache enabled -> powerloss = dataloss;
- WCE=0 -> small write cache segment enabled -> powerloss = nodataloss.
Unfortunately, I can not find anything on that regard about HGST's
MediaCache...
Regards.
[1]
https://www.seagate.com/www-content/product-content/enterprise-performance-savvio-fam/ent-perf-10k-hdd-v9-skybolt/en-us/docs/100818015c.pdf
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Danti Gionatan
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