In that case just make sure that RAID controller cache coherency is enabled, that is if you have shared storage with redundant controllers.<br><br>Wojciech<br><br><div class="gmail_quote">On 13 January 2012 12:04, Alexander Oltu <span dir="ltr"><<a href="mailto:Alexander.Oltu@uni.no">Alexander.Oltu@uni.no</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Wojciech, thanks! I forgot to mention that our disk storage will be on<br>
UPS.<br>
<br>
Alex.<br>
<div><div></div><div class="h5"><br>
On Fri, 13 Jan 2012 11:13:08 +0000<br>
Wojciech Turek wrote:<br>
<br>
> Make sure that use use RAID controller's with cache protected by<br>
> battery backup and if you use redundant controllers that the cache<br>
> mirroring feature is enabled. The ldiskfs (ext4) should recover after<br>
> power failures with no problems as long as the back end storage<br>
> recovers fine too.<br>
><br>
> Best regards,<br>
><br>
> Wojciech<br>
><br>
> On 13 January 2012 11:01, Alexander Oltu <<a href="mailto:Alexander.Oltu@uni.no">Alexander.Oltu@uni.no</a>><br>
> wrote:<br>
><br>
> > Hi,<br>
> ><br>
> > We are going to have a Lustre setup with around 1000 clients. Due<br>
> > to a power cable constraints we are not able to provide power to<br>
> > OSS and MDS servers from UPS.<br>
> ><br>
> > Therefore the question is how resilient is Lustre to OSS and/or MDS<br>
> > power failures?<br>
> ><br>
> > We have quite few thunderstorms here during summer with short power<br>
> > interruptions. I understand that ext4 is a journaling filesystem and<br>
> > should be more or less stable to power interruptions. But the real<br>
> > practice can be different. I believe that some of you have<br>
> > experience of running OSS and MDS without UPS and can shed some<br>
> > light on this topic.<br>
> ><br>
> > Thank you,<br>
> > Alex.<br>
> > _______________________________________________<br>
> > Lustre-discuss mailing list<br>
> > <a href="mailto:Lustre-discuss@lists.lustre.org">Lustre-discuss@lists.lustre.org</a><br>
> > <a href="http://lists.lustre.org/mailman/listinfo/lustre-discuss" target="_blank">http://lists.lustre.org/mailman/listinfo/lustre-discuss</a><br>
> ><br>
<br>
<br>
</div></div><font color="#888888">--<br>
Alexander Oltu<br>
System Engineer<br>
Parallab, Uni Computing<br>
<br>
HIB, Thormhlensgt.55<br>
N-5008 Bergen, Norway<br>
phone: <a href="tel:%2B47%2055584144" value="+4755584144">+47 55584144</a><br>
</font></blockquote></div><br>