On 28/01/2021 15.21, Per Jessen wrote:
Carlos E. R. wrote:
you're right, I know there is a setting to enable it. We check
every new drive when they are installed, just in case - we have not
seen any IBM/Hitachi/Seagate/WDC drive with write cache enabled in at
least 10 years. I don't know if we ever have, but we don't keep the
test records for longer than that.
Ok, you mean that hard disks that are specifically made for raid
usage, have the write cache disabled? Or that you manually disable it?
No, harddisks generally have write cache disabled because it is a
potential problem unless you have a UPS. Like I wrote, we check the
setting whenever we install or replace a drive. AFAIR, we had to make
a small utility, hdparm did not support it. Maybe it does now, I don't
Ah. I was trying to find how to enable or disable it in hdparm and
couldn't see it.
I don't know, I never purchased disks made
They are not specifically made for raid - WDC used to have a series
called "RAID edition", but I think they've stopped that.
I don't know if the default settings vary depending on whether they are
industry or consumer drives, it's possible. I also see write cache
enabled on my laptop, for instance.
Cheers / Saludos,
Carlos E. R.
(from 15.2 x86_64 at Telcontar)