<div dir="ltr">Hi Rob,<div><br></div><div>This is strange, since the filesystem DAX access uses essentially the same checks as DRBD does. You can get more detail about the failure by doing the mount test again after enabling the relevant debug logging as follows:</div><div>echo "file drivers/dax/super.c +p" > /sys/kernel/debug/dynamic_debug/control<br></div><div><br></div><div>Perhaps there is a subtle difference in the checks that DRBD does which is relevant for your device on this kernel.</div><div><br></div><div>Best regards,</div><div>Joel</div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Jun 12, 2019 at 8:04 AM Rob van der Wal <<a href="mailto:rob.vanderwal@surfsara.nl">rob.vanderwal@surfsara.nl</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
Hi Joel,<br>
<br>
Yes, I can mount with "-o dax":<br>
<br>
lvcreate -L 40G -n test-lv vg_ssd<br>
scan_dev_close /dev/sdb2 no DEV_IN_BCACHE set<br>
Logical volume "test-lv" created.<br>
mkfs.ext4 -b 4K /dev/vg_ssd/test-lv<br>
mount -o dax /dev/vg_ssd/test-lv /mnt<br>
df /mnt<br>
Filesystem 1K-blocks Used Available Use% Mounted
on<br>
/dev/mapper/vg_ssd-test--lv 41022688 49176 38859976 1% /mnt<br>
<br>
But it shows a failure in syslog:<br>
[518270.833954] EXT4-fs (dm-16): DAX enabled. Warning: EXPERIMENTAL,
use at your own risk<br>
[518270.833959] EXT4-fs (dm-16): DAX unsupported by block device.
Turning off DAX.<br>
[518270.835599] EXT4-fs (dm-16): mounted filesystem with ordered
data mode. Opts: dax<br>
<br>
Regards,<br>
Rob<br>
<br>
<br>
<div class="gmail-m_3095418601436962624moz-cite-prefix">On 6/11/19 3:57 PM, Joel Colledge
wrote:<br>
</div>
<blockquote type="cite">
<pre class="gmail-m_3095418601436962624moz-quote-pre">Hi Rob,
This is strange. It seems that your LV is reporting that it supports
PMEM/DAX. I suggest that you check that this issue also occurs without
DRBD. For example, create a filesystem and try to mount it with DAX
enabled:
mkfs.ext4 -b 4K /dev/<your-lv>
mount -o dax /dev/<your-lv> <somewhere>
The check the syslog to see whether DAX was successfully enabled. You
can see the expected success and failure output here:
<a class="gmail-m_3095418601436962624moz-txt-link-freetext" href="https://nvdimm.wiki.kernel.org/#filesystems" target="_blank">https://nvdimm.wiki.kernel.org/#filesystems</a>
Best regards,
Joel
PS Please "reply all" to keep the mailing list in CC
On Tue, Jun 11, 2019 at 2:53 PM Rob van der Wal
<a class="gmail-m_3095418601436962624moz-txt-link-rfc2396E" href="mailto:rob.vanderwal@surfsara.nl" target="_blank"><rob.vanderwal@surfsara.nl></a> wrote:
</pre>
<blockquote type="cite">
<pre class="gmail-m_3095418601436962624moz-quote-pre">Hi Joel,
I've build the module from source (downloaded from <a class="gmail-m_3095418601436962624moz-txt-link-freetext" href="https://www.linbit.com/en/drbd-community/drbd-download/" target="_blank">https://www.linbit.com/en/drbd-community/drbd-download/</a>).
I think we don't use external metadata and we are using a ssd disk for storing. This is a part of our drbd.conf:
drbd.conf:
on barentsz {
node-id 1;
device /dev/drbd0 minor 0;
disk /dev/vg_ssd/vm_prace-ldap;
meta-disk internal;
address ipv4 <a href="http://10.0.0.30:7788" target="_blank">10.0.0.30:7788</a>;
}
LVM info:
PV /dev/sdb2 VG vg_ssd lvm2 [446.43 GiB / 102.43 GiB free]
ACTIVE '/dev/vg_ssd/vm_prace-ldap' [38.00 GiB] inherit
The requested line in the syslog is:
[1037978.736262] drbd r0/0 drbd0: meta-data IO uses: dax-pmem
But I don't think we are using a PMEM device so this looks not correct.
Regards,
Rob van der Wal
</pre>
</blockquote>
</blockquote>
<br>
<div class="gmail-m_3095418601436962624moz-signature">-- <br>
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</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><font face="arial, helvetica, sans-serif" size="2"><span style="color:rgb(0,0,0)">Joel Colledge</span><span style="color:rgb(0,0,0)"> - </span><span style="color:rgb(0,0,0)">Software Developer</span><br style="color:rgb(0,0,0)"><a href="tel:+4318178292" style="color:rgb(0,0,0)" target="_blank">+43-1-817-82-92 x<span>53</span></a><br style="color:rgb(0,0,0)"><a href="mailto:joel.colledge@linbit.com" style="color:rgb(0,0,0)" target="_blank"><span>joel.colledge</span>@linbit.com</a><br style="color:rgb(0,0,0)"><br style="color:rgb(0,0,0)"><a href="http://www.linbit.com/en/" style="color:rgb(250,133,34)" target="_blank">LIN</a><a href="http://www.linbit.com/en/" style="color:rgb(0,0,0)" target="_blank">BIT</a><span style="color:rgb(0,0,0)"> | Keeping the Digital World Running</span><br style="color:rgb(0,0,0)"><span style="color:rgb(0,0,0)">DRBD HA - Disaster Recovery - Software-defined Storage</span><br style="color:rgb(0,0,0)"><a href="https://twitter.com/linbit" title="Twitter" style="color:rgb(0,172,237)" target="_blank">t</a><span style="color:rgb(0,0,0)"> / </span><a href="https://www.facebook.com/pg/linbitdrbd/posts/" title="Facebook" style="color:rgb(59,89,152)" target="_blank">f</a><span style="color:rgb(0,0,0)"> / </span><a href="https://www.linkedin.com/company/linbit" title="LinkedIn" style="color:rgb(0,123,182)" target="_blank">in</a><span style="color:rgb(0,0,0)"> / </span><a href="https://www.youtube.com/user/linbit" title="YouTube" style="color:rgb(255,0,0)" target="_blank">y</a><span style="color:rgb(0,0,0)"> / </span><a href="https://plus.google.com/+Linbit/about" title="Google+" style="color:rgb(221,75,57)" target="_blank">g+</a><br style="color:rgb(0,0,0)"><br style="color:rgb(0,0,0)"><span style="color:rgb(0,0,0)">DRBD® and LINBIT® are registered trademarks of LINBIT, Austria.</span></font><br></div></div></div></div></div></div></div>