<html>
<head>
<meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<p><tt>For volume backups you need something like snapshots.</tt></p>
<p><tt>If you take a snapshot A of a live volume L that snapshot
stays at that moment in time and you can rsync that to another
system or use something like deltacp.pl to copy it.</tt></p>
<p><tt>The usual process is to delete the snapshot once its copied
and than repeat the process again when the next backup is
required.</tt></p>
<p><tt>That process does require rsync/deltacp to read the complete
volume on both systems which can take a long time.<br>
</tt></p>
<p><tt>I was kicking around the idea to try and handle snapshot
deltas better.</tt></p>
<p><tt>The idea is that you could take your initial snapshot A then
sync that snapshot to your backup system.</tt></p>
<p><tt>At a later point you could take another snapshot B.</tt></p>
<p><tt>Because snapshots contain the copies of the original data at
the time of the snapshot and unmodified data points to the Live
volume it is possible to tell what blocks of data have changed
since the snapshot was taken.</tt></p>
<p><tt>Now that you have a second snapshot you can in essence perform
a diff on the A and B snapshots to get only the blocks that
changed up to the time that B was taken.</tt></p>
<p><tt>These blocks could be copied to the backup image and you
should have a clone of the B snapshot.</tt></p>
<p><tt>You would not have to read the whole volume image but just
the changed blocks dramatically improving the speed of the
backup.<br>
</tt></p>
<p><tt>At this point you can delete the A snapshot and promote the B
snapshot to be the A snapshot for the next backup round.<br>
</tt></p>
<br>
<div class="moz-cite-prefix">On 03/23/2017 03:53 PM, Gandalf
Corvotempesta wrote:<br>
</div>
<blockquote
cite="mid:CAJH6TXhLTfGo5UTio+U7w5KyNWJ9uDgPWSY0LY9m+-ZcAj_9bQ@mail.gmail.com"
type="cite">
<div dir="auto">Are backup consistent?
<div dir="auto">What happens if the header on shard0 is synced
referring to some data on shard450 and when rsync parse
shard450 this data is changed by subsequent writes?</div>
<div dir="auto"><br>
</div>
<div dir="auto">Header would be backupped of sync respect the
rest of the image</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">Il 23 mar 2017 8:48 PM, "Joe Julian"
<<a moz-do-not-send="true"
href="mailto:joe@julianfamily.org">joe@julianfamily.org</a>>
ha scritto:<br type="attribution">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<p>The rsync protocol only passes blocks that have
actually changed. Raw changes fewer bits. You're right,
though, that it still has to check the entire file for
those changes.<br>
</p>
<br>
<div class="m_2071367206087675765moz-cite-prefix">On
03/23/17 12:47, Gandalf Corvotempesta wrote:<br>
</div>
<blockquote type="cite">
<div dir="auto">Raw or qcow doesn't change anything
about the backup.
<div dir="auto">Georep always have to sync the whole
file</div>
<div dir="auto"><br>
</div>
<div dir="auto">Additionally, raw images has much less
features than qcow</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">Il 23 mar 2017 8:40 PM, "Joe
Julian" <<a moz-do-not-send="true"
href="mailto:joe@julianfamily.org" target="_blank">joe@julianfamily.org</a>>
ha scritto:<br type="attribution">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<p>I always use raw images. And yes, sharding
would also be good.<br>
</p>
<br>
<div
class="m_2071367206087675765m_-8052554343169692798moz-cite-prefix">On
03/23/17 12:36, Gandalf Corvotempesta wrote:<br>
</div>
<blockquote type="cite">
<div dir="auto">Georep expose to another
problem:
<div dir="auto">When using gluster as
storage for VM, the VM file is saved as
qcow. Changes are inside the qcow, thus
rsync has to sync the whole file every
time</div>
<div dir="auto"><br>
</div>
<div dir="auto">A little workaround would be
sharding, as rsync has to sync only the
changed shards, but I don't think this is
a good solution</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">Il 23 mar 2017 8:33
PM, "Joe Julian" <<a
moz-do-not-send="true"
href="mailto:joe@julianfamily.org"
target="_blank">joe@julianfamily.org</a>>
ha scritto:<br type="attribution">
<blockquote class="gmail_quote"
style="margin:0 0 0 .8ex;border-left:1px
#ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<p>In many cases, a full backup set is
just not feasible. Georep to the
same or different DC may be an
option if the bandwidth can keep up
with the change set. If not, maybe
breaking the data up into smaller
more manageable volumes where you
only keep a smaller set of critical
data and just back that up. Perhaps
an object store (swift?) might
handle fault tolerance distribution
better for some workloads.</p>
<p>There's no one right answer.</p>
<br>
<div
class="m_2071367206087675765m_-8052554343169692798m_-3599642909736746536moz-cite-prefix">On
03/23/17 12:23, Gandalf
Corvotempesta wrote:<br>
</div>
<blockquote type="cite">
<div dir="auto">Backing up from
inside each VM doesn't solve the
problem
<div dir="auto">If you have to
backup 500VMs you just need more
than 1 day and what if you have
to restore the whole gluster
storage?</div>
<div dir="auto"><br>
</div>
<div dir="auto">How many days do
you need to restore 1PB?</div>
<div dir="auto"><br>
</div>
<div dir="auto">Probably the only
solution should be a georep in
the same datacenter/rack with a
similiar cluster, </div>
<div dir="auto">ready to became
the master storage.</div>
<div dir="auto">In this case you
don't need to restore anything
as data are already there, </div>
<div dir="auto">only a little bit
back in time but this double the
TCO</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">Il 23 mar
2017 6:39 PM, "Serkan Çoban"
<<a moz-do-not-send="true"
href="mailto:cobanserkan@gmail.com"
target="_blank">cobanserkan@gmail.com</a>>
ha scritto:<br
type="attribution">
<blockquote class="gmail_quote"
style="margin:0 0 0
.8ex;border-left:1px #ccc
solid;padding-left:1ex">Assuming
a backup window of 12 hours,
you need to send data at
25GB/s<br>
to backup solution.<br>
Using 10G Ethernet on hosts
you need at least 25 host to
handle 25GB/s.<br>
You can create an EC gluster
cluster that can handle this
rates, or<br>
you just backup valuable data
from inside VMs using open
source backup<br>
tools like borg,attic,restic ,
etc...<br>
<br>
On Thu, Mar 23, 2017 at 7:48
PM, Gandalf Corvotempesta<br>
<<a moz-do-not-send="true"
href="mailto:gandalf.corvotempesta@gmail.com" target="_blank">gandalf.corvotempesta@gmail.c<wbr>om</a>>
wrote:<br>
> Let's assume a 1PB
storage full of VMs images
with each brick over ZFS,<br>
> replica 3, sharding
enabled<br>
><br>
> How do you backup/restore
that amount of data?<br>
><br>
> Backing up daily is
impossible, you'll never
finish the backup that the<br>
> following one is starting
(in other words, you need more
than 24 hours)<br>
><br>
> Restoring is even worse.
You need more than 24 hours
with the whole cluster<br>
> down<br>
><br>
> You can't rely on ZFS
snapshot due to sharding (the
snapshot took from one<br>
> node is useless without
all other node related at the
same shard) and you<br>
> still have the same
restore speed<br>
><br>
> How do you backup this?<br>
><br>
> Even georep isn't enough,
if you have to restore the
whole storage in case<br>
> of disaster<br>
><br>
>
______________________________<wbr>_________________<br>
> Gluster-users mailing
list<br>
> <a
moz-do-not-send="true"
href="mailto:Gluster-users@gluster.org"
target="_blank">Gluster-users@gluster.org</a><br>
> <a
moz-do-not-send="true"
href="http://lists.gluster.org/mailman/listinfo/gluster-users"
rel="noreferrer"
target="_blank">http://lists.gluster.org/mailm<wbr>an/listinfo/gluster-users</a><br>
</blockquote>
</div>
</div>
<br>
<fieldset
class="m_2071367206087675765m_-8052554343169692798m_-3599642909736746536mimeAttachmentHeader"></fieldset>
<br>
<pre>______________________________<wbr>_________________
Gluster-users mailing list
<a moz-do-not-send="true" class="m_2071367206087675765m_-8052554343169692798m_-3599642909736746536moz-txt-link-abbreviated" href="mailto:Gluster-users@gluster.org" target="_blank">Gluster-users@gluster.org</a>
<a moz-do-not-send="true" class="m_2071367206087675765m_-8052554343169692798m_-3599642909736746536moz-txt-link-freetext" href="http://lists.gluster.org/mailman/listinfo/gluster-users" target="_blank">http://lists.gluster.org/mailm<wbr>an/listinfo/gluster-users</a></pre>
</blockquote>
</div>
______________________________<wbr>_________________
Gluster-users mailing list
<a moz-do-not-send="true" href="mailto:Gluster-users@gluster.org" target="_blank">Gluster-users@gluster.org</a>
<a moz-do-not-send="true" href="http://lists.gluster.org/mailman/listinfo/gluster-users" rel="noreferrer" target="_blank">http://lists.gluster.org/mailm<wbr>an/listinfo/gluster-users</a>
</blockquote></div></div>
</blockquote>
</div></blockquote></div></div>
</blockquote>
</div></blockquote></div></div>
<fieldset class="mimeAttachmentHeader"></fieldset>
<pre wrap="">_______________________________________________
Gluster-users mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Gluster-users@gluster.org">Gluster-users@gluster.org</a>
<a class="moz-txt-link-freetext" href="http://lists.gluster.org/mailman/listinfo/gluster-users">http://lists.gluster.org/mailman/listinfo/gluster-users</a></pre>
</blockquote>
<pre class="moz-signature" cols="72">--
Alvin Starr || voice: (905)513-7688
Netvel Inc. || Cell: (416)806-0133
<a class="moz-txt-link-abbreviated" href="mailto:alvin@netvel.net">alvin@netvel.net</a> ||
</pre></body></html>