<div dir="ltr"><div>Jeff Darcy, GlusterFS developer, responded here: <a href="https://news.ycombinator.com/item?id=6359851">https://news.ycombinator.com/item?id=6359851</a><br><br></div><div>I'm not sure what the OP was trying to achieve if he didn't completely understand what he was talking about.<br>
</div><div><br></div>Pasting Jeff's comments:<br><br><span class=""><font color="#000000">GlusterFS developer here. The OP is extremely misleading, so I'll try to set the record straight.<p>(1)
Granted, snapshots (volume or file level) aren't implemented yet.
OTOH, there are two projects for file-level snapshots that are far
enough along to have patches in either the main review queue or the
community forge. Volume-level snapshots are a little further behind.
Unsurprisingly, snapshots in a distributed filesystem are hard, and
we're determined to get them right before we foist some half-baked
result on users and risk losing their data.</p><p>(2) The author seems
very confused about the relationship between bricks (storage units) and
servers used for mounting. The mount server is used <i>once</i> to
fetch a configuration, then the client connects directly to the bricks.
There is no need to specify all of the bricks on the mount command; one
need only specify enough servers - two or three - to handle one being
down <i>at mount time</i>. RRDNS can also help here.</p><p>(3) Lack of
support for login/password authentication. This has not been true in
the I/O path since forever; it only affects the CLI, which should only
be run from the servers themselves (or similarly secure hosts) anyway.
It should not be run from arbitrary hosts. Adding full SSL-based auth
is already an accepted feature for GlusterFS 3.5 and some of the patches
are already in progress. Other management interfaces already have
stronger auth.</p><p>(4) Volumes can be mounted R/W from many locations.
This is actually a strength, since volumes are files. Unlike some
alternatives, GlusterFS provides true multi-protocol access - not just
different silos for different interfaces within the same infrastructure
but the <i>same data</i> accessible via (deep breath) native protocol,
NFS, SMB, Swift, Cinder, Hadoop FileSystem API, or raw C API. It's up
to the cloud infrastructure (e.g. Nova) not to mount the same
block-storage device from multiple locations, <i>just as with every alternative</i>.</p><p>(5)
What's even more damning than what the author says is what the author
doesn't say. There are benefits to having full POSIX semantics so that
hundreds of thousands of programs and scripts that don't speak other
storage APIs can use the data. There are benefits to having the same
data available through many protocols. There are benefits to having
data that's shared at a granularity finer than whole-object GET and PUT,
with familiar permissions and ACLs. There are benefits to having a
system where any new feature - e.g. georeplication, erasure coding,
deduplication - immediately becomes available across all access
protocols. Every performance comparison I've seen vs. obvious
alternatives has either favored GlusterFS or revealed cheating (e.g.
buffering locally or throwing away O_SYNC) by the competitor. Or both.
Of course, the OP has already made up his mind so he doesn't mention
any of this.</p></font><p><font color="#000000">It's perfectly fine that
the author prefers something else. He mentions Ceph. I love Ceph. I
also love XtreemFS, which hardly anybody seems to know about and that's a
shame. We're all on the same side, promoting open-source horizontally
scalable filesystems vs. worse alternatives - proprietary storage,
non-scalable storage, storage that can't be mounted and used in familiar
ways by normal users. When we've won that battle we can fight over the
spoils. ;) The point is that <i>even for a Cinder use case</i> the
author's preferences might not apply to anyone else, and they certainly
don't apply to many of the more general use cases that all of these
systems are designed to support.</font></p></span><br></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Tue, Sep 10, 2013 at 9:15 AM, Diego Parrilla Santamaría <span dir="ltr"><<a href="mailto:diego.parrilla.santamaria@gmail.com" target="_blank">diego.parrilla.santamaria@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">You are describing the problems of using a shared filesystem backend for cinder, instead of using a driver with direct connection at block-device level.<div>
<br></div><div>It has improved a lot in the last 18 months or so, specially if you want to use as shared storage for your VMs.</div>
<div><br></div><div>Seems the snapshotting feature is on the way:</div><div><a href="https://github.com/openstack/cinder/blob/master/cinder/volume/drivers/glusterfs.py" target="_blank">https://github.com/openstack/cinder/blob/master/cinder/volume/drivers/glusterfs.py</a></div>
<div><br></div><div>But the killer feature is the direct access from QEMU to Gluster using libgfapi. It seems it has been added in Havana and it's in master branch since mid August:</div><div><a href="https://review.openstack.org/#/c/39498/" target="_blank">https://review.openstack.org/#/c/39498/</a></div>
<div><br></div><div>If I had to consider a scalable storage solution for an Openstack deployment for the next 10 years, I would consider Gluster.</div><div><br></div><div>Cheers</div><div>Diego</div><div><br></div><div><br>
<div><br></div></div><div><br></div></div><div class="gmail_extra"><br clear="all"><div> -- <br><span style="border-collapse:separate;font-family:Times"><span style="border-collapse:collapse;font-family:arial,sans-serif"><div style="font-size:13px" align="left">
<div><font><span style="font-family:Arial" lang="ES">Diego Parrilla<br><a href="http://www.stackops.com/" title="file:///C:/Documents%20and%20Settings/carolina.capsir.per1/Application%20Data/Microsoft/Signatures/www.garrigues.com
www.garrigues.com" style="color:rgb(7,77,143)" target="_blank"><span title="file:///C:/Documents%20and%20Settings/carolina.capsir.per1/Application%20Data/Microsoft/Signatures/www.garrigues.com"></span></a></span></font><font style="font-family:arial,helvetica,sans-serif" face="Arial"><b>CEO</b><font size="1"><br>
</font></font><span style="border-collapse:separate;font-family:Times;font-size:medium"><span style="border-collapse:collapse;font-family:arial,sans-serif;font-size:13px"></span></span><b><font style="font-family:arial,helvetica,sans-serif" face="Arial"><a href="http://www.stackops.com/" target="_blank"><b>www.stackops.com</b></a> | </font></b><font style="font-family:arial,helvetica,sans-serif" face="Arial"><font size="1"> <a href="mailto:diego.parrilla@stackops.com" target="_blank">diego.parrilla@stackops.com</a></font></font><span style="border-collapse:separate;font-family:Times;font-size:medium"><span style="border-collapse:collapse;font-family:arial,sans-serif;font-size:13px"><font color="#004438" face="Arial"><b><b><span style="font-size:10pt" lang="EN-GB"></span></b></b></font></span></span><font style="font-family:arial,helvetica,sans-serif" face="Arial"><font size="1"> | </font></font><span style="border-collapse:separate;font-family:Times;font-size:medium"><span style="border-collapse:collapse;font-family:arial,sans-serif;font-size:13px"><font style="font-family:arial,helvetica,sans-serif" face="Arial"><font size="1"><a href="tel:%2B34%20649%2094%2043%2029" value="+34649944329" target="_blank">+34 649 94 43 29</a> | <a>skype:diegoparrilla</a></font></font></span></span><font style="font-family:arial,helvetica,sans-serif" face="Arial"><a href="http://www.stackops.com/" target="_blank"><b><br>
</b></a></font></div></div><div style="font-size:13px"><font color="#004438" face="Arial"><b><p><span style="border-collapse:separate;font-size:medium;font-family:Times"><span style="border-collapse:collapse;font-family:arial,sans-serif;font-size:13px"><span style="border-collapse:separate;font-family:Times;font-size:medium"><span style="border-collapse:collapse;font-family:arial,sans-serif;font-size:13px"><font color="#004438" face="Arial"><b><b><span style="font-size:10pt" lang="EN-GB"><img></span></b></b></font></span></span></span></span></p>
</b></font></div></span></span><div><br></div></div>
<br><br><div class="gmail_quote">On Tue, Sep 10, 2013 at 2:36 PM, Maciej Gałkiewicz <span dir="ltr"><<a href="mailto:macias@shellycloud.com" target="_blank">macias@shellycloud.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hello<br>
<br>
For everyone looking for some info regarding GlusterFS and Openstack<br>
integration I suggest my blog post:<br>
<a href="https://shellycloud.com/blog/2013/09/why-glusterfs-should-not-be-implemented-with-openstack" target="_blank">https://shellycloud.com/blog/2013/09/why-glusterfs-should-not-be-implemented-with-openstack</a><br>
<br>
regards<span class="HOEnZb"><font color="#888888"><br>
<span><font color="#888888">--<br>
Maciej Gałkiewicz<br>
Shelly Cloud Sp. z o. o., Sysadmin<br>
<a href="http://shellycloud.com/" target="_blank">http://shellycloud.com/</a>, <a href="mailto:macias@shellycloud.com" target="_blank">macias@shellycloud.com</a><br>
KRS: 0000440358 REGON: 101504426<br>
<br>
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