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<DIV><FONT size=2 face=Arial>In a previous post i read (<EM>Tue Nov 26 18:45:15
CET 2013)</EM>:</FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><FONT face=Arial><FONT size=2><FONT
face=Arial><FONT size=2><FONT size=2
face=Arial></FONT></FONT></FONT></FONT></FONT></FONT></FONT> </DIV>
<DIV><FONT size=2 face=Arial>- Eric Blevins say:</FONT></DIV>
<DIV><FONT size=2 face=Arial>> I have a suggestion that would help alleviate
the read and write downsides to<BR>> this.<BR>> <BR>> Create a memory
buffer where the reads/writes from the VM are placed.<BR>> When buffer is
over a certain percentage, stop the backup read operations and<BR>> flush the
buffer.<BR>> The VM can perform IO up to the limit of the memory buffer with
little loss in<BR>> performance.<BR></FONT></DIV>
<DIV><FONT size=2 face=Arial>- And Dietmar Maurer <SPAN id=result_box lang=en
class=short_text><SPAN class=hps>answers:</SPAN></SPAN><BR>That is how it works
already.<BR><BR>Anyways, I will try to upgrade KVM to 1.7 first (many backup
related changes). <BR>We can then test again and try to optimize
further.</FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><FONT face=Arial><FONT size=2><FONT size=2
face=Arial></FONT></FONT></FONT></FONT></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Then, I say now:</FONT></DIV>
<DIV><FONT size=2 face=Arial>-----------------------</FONT></DIV>
<DIV><FONT size=2 face=Arial>The mbuffers for writes can be a serious problem if
the PVE Host that have the VM in HA is decomposes during the process of backup,
because i will lose data of this VM when this VM starts in the other PVE Node
that is alive</FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><FONT size=2
face=Arial></FONT></FONT></FONT> </DIV>
<DIV><FONT size=2 face=Arial>And my Questions:</FONT></DIV>
<DIV><FONT size=2 face=Arial>---------------------------</FONT></DIV>
<DIV><FONT size=2 face=Arial>1- "KVM live Backup" with the new code of backup,
will do write cache for use of the VM?<BR>2- If the question above is correct,
how much write cache will make this new code of backup?<BR>And the question
more important:<BR>3- If the first question is correct, is possible to make a
new code of "KVM live Backup" that don't make write cache for use of the VM and
nor affect the I/O performance of the VM?<BR></FONT></DIV>
<DIV><FONT size=2 face=Arial>Best regrads</FONT></DIV>
<DIV><FONT size=2 face=Arial>Cesar</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>----- Original Message ----- </FONT>
<DIV><FONT size=2 face=Arial>From: "Dietmar Maurer" <</FONT><A
href="mailto:dietmar@proxmox.com"><FONT size=2
face=Arial>dietmar@proxmox.com</FONT></A><FONT size=2
face=Arial>></FONT></DIV>
<DIV><FONT size=2 face=Arial>To: "Cesar Peschiera" <</FONT><A
href="mailto:brain@click.com.py"><FONT size=2
face=Arial>brain@click.com.py</FONT></A><FONT size=2 face=Arial>>;
<</FONT><A href="mailto:pve-devel@pve.proxmox.com"><FONT size=2
face=Arial>pve-devel@pve.proxmox.com</FONT></A><FONT size=2
face=Arial>></FONT></DIV>
<DIV><FONT size=2 face=Arial>Sent: Tuesday, January 28, 2014 2:52
AM</FONT></DIV>
<DIV><FONT size=2 face=Arial>Subject: RE: [pve-devel] KVM Live Backup
performance</FONT></DIV></DIV>
<DIV><FONT face=Arial><BR><FONT size=2></FONT></FONT></DIV><FONT size=2
face=Arial>> If is possible without lose performance into this VM, the write
cache for "KVM<BR>> Live Backup" not must to execute it. In this mode the
"KVM Live Backup" will be<BR>> fantastic.<BR><BR>Sorry, but I do not really
understand that question?<BR><BR>We have done many improvement on backup code,
so you should first test with the newest binaries<BR>available on the 'pvetest'
repository.<BR><BR></FONT></BODY></HTML>