From: Kent Overstreet <kent.overstreet@gmail.com>
To: Martin McClure <martin.mcclure@gemtalksystems.com>, chris@cooperteam.net
Cc: linux-bcache@vger.kernel.org
Subject: Re: bcachefs with cache device and backing device
Date: Tue, 17 May 2016 20:01:03 -0800 [thread overview]
Message-ID: <20160518040103.GA13870@moria.home.lan> (raw)
In-Reply-To: <573BD789.9030406@gemtalksystems.com>
On Tue, May 17, 2016 at 07:46:33PM -0700, Martin McClure wrote:
> On 05/12/2016 09:36 PM, Kent Overstreet wrote:
> >
> > Yeah - tiering replaces cache/backing devices
> >
> > IIRC,
> >
> > bcache format --tier 0 -C <SSD> --tier 1 -C <spinning rust>
> >
> > (the -C is going to go away at some point)
> >
>
> Had a chance to play with this some more, but still not getting it to
> work...
>
> Formatting seems to work, and once I do this:
>
> echo /dev/sdd1 > /sys/fs/bcache/register
> echo /dev/nvme0n1 > /sys/fs/bcache/register
> echo 1 > /sys/fs/bcache/<set-uuid>/blockdev_volume_create
>
> a /dev/bcache0 has been created. However, if I try to mount it:
>
> mount -t bcache /dev/bcache0 /mnt
>
> it says:
>
> mount: No such file or directory
>
> with a return code of 32, which is documented as "mount failure".
>
> At this point I reach the limit of my current understanding, but would
> like to understand more.
The intended mount path for multi device filesystems is currently broken...
Chris got it working (to my surprise) by - I belive - registering all the
devices via /sys/fs/bcache/register, and then mounting just one of the block
devices - Chris, is that correct?
FYI though: tiering mode is _not_ as well tested currently, and Chris managed to
hit a bug when he completely filled up tier 0 and it then wouldn't mount,
because the btree updates journal replay was doing wouldn't fit on tier 0 - and
I haven't merged the fix I sent him because it was kind of a hack.
But I just got back from vacation so I should be able to start working through
these issues...
next prev parent reply other threads:[~2016-05-18 4:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-13 1:50 bcachefs with cache device and backing device Martin McClure
2016-05-13 4:36 ` Kent Overstreet
2016-05-13 4:37 ` Martin McClure
2016-05-18 2:46 ` Martin McClure
2016-05-18 4:01 ` Kent Overstreet [this message]
2016-05-18 5:06 ` Christopher James Halse Rogers
2016-05-18 5:41 ` Kent Overstreet
2016-05-20 0:41 ` Martin McClure
2016-05-20 0:44 ` Christopher James Halse Rogers
2016-05-20 1:18 ` Martin McClure
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=20160518040103.GA13870@moria.home.lan \
--to=kent.overstreet@gmail.com \
--cc=chris@cooperteam.net \
--cc=linux-bcache@vger.kernel.org \
--cc=martin.mcclure@gemtalksystems.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).