<div dir="ltr">Hi,<br><br>ok i will look further into the drive cache.<br><br>But i found an MySQL option <code class="literal">sync_binlog</code> if its set to 1 <br>the failover is ok. <br><br>now i will look if i losst any data.<br>
<br><br>Thanks for your help<br>Mark <br><br><div class="gmail_quote">On Fri, Aug 1, 2008 at 4:51 PM, Lee Christie <span dir="ltr"><<a href="mailto:Lee@titaninternet.co.uk">Lee@titaninternet.co.uk</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2">Hi Mark</font></span></div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2">we're talking about drive cache here, not raid adapter
cache.</font></span></div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2">on SCSI/SATA drives the cache is typically a jumper or a
firmware setting that has to be changed via a manufacturer utility. On the later
SAS drives it is software controllable through your raid adapter provided that
your vendor has implemented the functionality.</font></span></div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2">By default raid adapters have writethrough cache ON and
writeback cache OFF - unless you have a battery backup unit in which case the
default will be writeback ON.</font></span></div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2">After the defaults anything is possible. The cards we use
are set to use writeback with BBU, but if a drive fails the card switches to
writethrough for additional security.</font></span></div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div><br>
<blockquote style="border-left: 2px solid rgb(0, 0, 255); padding-left: 5px; margin-left: 5px; margin-right: 0px;">
<div align="left">
<hr>
<font face="Tahoma" size="2"><b>From:</b> Mark Eisenblaetter
[mailto:<a href="mailto:mark.eisenblaetter@gmail.com" target="_blank">mark.eisenblaetter@gmail.com</a>] <br><b>Sent:</b> 01 August 2008
15:27<br><b>To:</b> Lee Christie<br><b>Cc:</b>
<a href="mailto:drbd-user@lists.linbit.com" target="_blank">drbd-user@lists.linbit.com</a><br><b>Subject:</b> Re: [DRBD-user] Mysql on DRBD:
Cache Problem?<br></font><br></div><div><div></div><div class="Wj3C7c">
<div></div>
<div>Hi Lee,<br><br>it seems taht my P400i has no drivewritecache
option.<br>Wenn i try to modify it comes up whit an error. And in one document
i fount that it's default of in P800 controllers,<br>so i hope in my p400i
too.<br><br>Mark<br><br>
<div class="gmail_quote">On Fri, Aug 1, 2008 at 3:33 PM, Lee Christie
<span><<a href="mailto:Lee@titaninternet.co.uk" target="_blank">Lee@titaninternet.co.uk</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2">Most hard drives
ship with write-cache enabled.</font></span></div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2">When using
decent raid controllers its best to turn off the write(back) cache on hard
drives. In our testing it makes no difference anyway with a good
card.</font></span></div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div align="left"><span><font color="#0000ff" face="Arial" size="2">Its possible
your lost data was in hard drive cache.</font></span></div><br>
<blockquote style="border-left: 2px solid rgb(0, 0, 255); padding-left: 5px; margin-left: 5px; margin-right: 0px;">
<div align="left">
<hr>
<font face="Tahoma" size="2"><b>From:</b> <a href="mailto:drbd-user-bounces@lists.linbit.com" target="_blank">drbd-user-bounces@lists.linbit.com</a>
[mailto:<a href="mailto:drbd-user-bounces@lists.linbit.com" target="_blank">drbd-user-bounces@lists.linbit.com</a>]
<b>On Behalf Of </b>Mark Eisenblaetter<br><b>Sent:</b> 01 August 2008
14:22<br><b>To:</b> <a href="mailto:drbd-user@lists.linbit.com" target="_blank">drbd-user@lists.linbit.com</a><br><b>Subject:</b>
[DRBD-user] Mysql on DRBD: Cache Problem?<br></font><br></div>
<div>
<div></div>
<div>
<div></div>
<div>Hi List,<br><br>I'm trying to run a DRBDMySQL Cluster
(Active/Passive) with Replication for easier backup.<br><br>My problem ist
that after a hardkill from the master(Powerkill) the slave misses binlog
positions.<br><br>After disable the Arraycontroller Write cache its
reduced from 100k to 16k Position but that not enough.<br><br>I run DRBD
with Protocal C and the minimal max-buffer of 32k.<br><br>Is there any
cache i miss? Or somthing else?<br><br>Mark<br><br><br>setup: 2x HP
DL360G5 whit raid 10 and Gigabit network for drbdsync only.
<br><br>-- <br>Mark Eisenblätter<br>Geissendoerfer & Leschinsky
GmbH<br><a href="http://www.gl-sytemhaus.de" target="_blank">www.gl-sytemhaus.de</a><br></div></div></div></blockquote></div><font face="Tahoma" size="2"><font color="#0000ff">
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<p align="left"><font face="Tahoma" size="2"><font color="#0000ff">Unless expressly stated to the contrary this e-mail is not intended to, and shall not, have any contractually binding effect on the Company and its clients. We accept no liability for any reliance placed on this e-mail other than to the intended recipient. If the content is not about the business of this Company or its clients then the message is neither from nor sanctioned by the Company. </font></font></p>
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</div></div></blockquote></div><br><br clear="all"><br>-- <br>Mark Eisenblätter<br>Geissendoerfer & Leschinsky GmbH<br><a href="http://www.gl-sytemhaus.de">www.gl-sytemhaus.de</a><br>
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