From: marc.smith@mcc.edu (Marc Smith)
Subject: Find Allocation Unit Size
Date: Fri, 14 Dec 2018 10:44:39 -0500 [thread overview]
Message-ID: <CAHkw+Le5jSaNbQ+eZjARNhNpBHAOxfqEjoTUC8to1_HDiJYzhw@mail.gmail.com> (raw)
In-Reply-To: <20181214144159.GB13491@localhost.localdomain>
On Fri, Dec 14, 2018@9:44 AM Keith Busch <keith.busch@intel.com> wrote:
>
> On Fri, Dec 14, 2018@01:39:42AM -0500, Marc Smith wrote:
> > Hi,
> >
> > I'm testing some NVMe drives, and playing with creating multiple
> > namespaces (via the nvme CLI tool). I've noticed with some values,
> > there is rounding that is occurring (or so I assume). I'm using a 4096
> > block size, and with values like 200 GiB or 1000 GiB I do not see the
> > rounding occur (checking value in bytes against unvmcap after
> > creation).
> >
> > But other values do seem to round... I suspect this is aligning to the
> > allocation unit size, but I'm not sure where to find that value for my
> > NVMe drives? Hoping someone could point me in the right direction!
> >
> > Thanks in advance.
>
> The spec says a device may have a minimal size granularity for creating
> namespaces, but currently doesn't provide a way to discover what that is.`
Interesting... do you believe that is something that the device
manufacturer can (or will) provide? Or maybe something in the device
spec sheet (going to check that now...)?
Thanks for the quick response.
--Marc
prev parent reply other threads:[~2018-12-14 15:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-14 6:39 Find Allocation Unit Size Marc Smith
2018-12-14 14:41 ` Keith Busch
2018-12-14 15:44 ` Marc Smith [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAHkw+Le5jSaNbQ+eZjARNhNpBHAOxfqEjoTUC8to1_HDiJYzhw@mail.gmail.com \
--to=marc.smith@mcc.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.