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Right, I have solved this by:<br>
<br>
sysctl vm.dirty_ratio=2<br>
<br>
mdadm --create --verbose /dev/md2 --level=raid6 -n5 -f /dev/sda2
/dev/sdb2 /dev/sdc2 /dev/sdd2 /dev/sde2<br>
<br>
mkfs.xfs -b size=4096 -d sunit=512,swidth=1536 -L data /dev/md2<br>
<br>
and fstab:<br>
/dev/md2 /data xfs noatime,sunit=512,swidth=1536
0 0<br>
<br>
Not sure if it was any one of these that have fixed it up, or the
combination of all of the above but now the thing does not stop
writing and all of my vm's are running.<br>
<br>
Thanks<br>
<br>
Jurgen<br>
<div class="moz-cite-prefix">On 15/08/12 02:12, Shankhadeep Shome
wrote:<br>
</div>
<blockquote
cite="mid:CAOK6JGZHOzNaWZsEmY2bUUqD54E1yhpD_9n6=w7pMwN1ng_=sA@mail.gmail.com"
type="cite">A hard crash with high i/o can be due to bad memory
modules, I would run a memory burn program to make sure your
hardware is actually stable.
<div><br>
</div>
<div>Shank<br>
<br>
<div class="gmail_quote">On Tue, Aug 14, 2012 at 2:42 AM, Jurgen
Weber <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:jurgen.weber@theiconic.com.au"
target="_blank">jurgen.weber@theiconic.com.au</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">Hi Guys<br>
<br>
I have a new KVM server, running software raid (mdadm) and
the VM disk are help in a raid 5 with 5 disks (the system is
on SSDs in a mirror).<br>
<br>
So far I have about 10 VM's setup, but they are all unable
to function because after we have a few up, and then start
to deploy/resubmit the VM's which have never booted properly
the disk IO will stop, the scp process will hang and it all
stops. You will then find the following error in dmesg:<br>
<br>
[ 1201.890311] INFO: task kworker/1:1:6185 blocked for more
than 120 seconds.<br>
[ 1201.890430] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.<br>
[ 1201.890569] kworker/1:1 D ffff88203fc13740 0
6185 2 0x00000000<br>
[ 1201.890573] ffff881ffe510140 0000000000000046
0000000000000000 ffff881039023590<br>
[ 1201.890580] 0000000000013740 ffff8820393fffd8
ffff8820393fffd8 ffff881ffe510140<br>
[ 1201.890586] 0000000000000000 0000000100000000
0000000000000001 7fffffffffffffff<br>
[ 1201.890593] Call Trace:<br>
[ 1201.890597] [<ffffffff81349d2e>] ?
schedule_timeout+0x2c/0xdb<br>
[ 1201.890605] [<ffffffff810ebdbf>] ?
kmem_cache_alloc+0x86/0xea<br>
[ 1201.890610] [<ffffffff8134a58a>] ?
__down_common+0x9b/0xee<br>
[ 1201.890631] [<ffffffffa0452c57>] ?
xfs_getsb+0x28/0x3b [xfs]<br>
[ 1201.890635] [<ffffffff81063111>] ? down+0x25/0x34<br>
[ 1201.890648] [<ffffffffa041566f>] ?
xfs_buf_lock+0x65/0x9d [xfs]<br>
[ 1201.890665] [<ffffffffa0452c57>] ?
xfs_getsb+0x28/0x3b [xfs]<br>
[ 1201.890685] [<ffffffffa045b957>] ?
xfs_trans_getsb+0x64/0xb4 [xfs]<br>
[ 1201.890704] [<ffffffffa0452a40>] ?
xfs_mod_sb+0x21/0x77 [xfs]<br>
[ 1201.890720] [<ffffffffa0422736>] ?
xfs_reclaim_inode+0x22d/0x22d [xfs]<br>
[ 1201.890734] [<ffffffffa041a43e>] ?
xfs_fs_log_dummy+0x61/0x75 [xfs]<br>
[ 1201.890754] [<ffffffffa04573a7>] ?
xfs_log_need_covered+0x4d/0x8d [xfs]<br>
[ 1201.890769] [<ffffffffa0422770>] ?
xfs_sync_worker+0x3a/0x6a [xfs]<br>
[ 1201.890773] [<ffffffff8105aeaa>] ?
process_one_work+0x163/0x284<br>
[ 1201.890778] [<ffffffff8105be72>] ?
worker_thread+0xc2/0x145<br>
[ 1201.890782] [<ffffffff8105bdb0>] ?
manage_workers.isra.23+0x15b/0x15b<br>
[ 1201.890787] [<ffffffff8105efad>] ?
kthread+0x76/0x7e<br>
[ 1201.890794] [<ffffffff81351cf4>] ?
kernel_thread_helper+0x4/0x10<br>
[ 1201.890799] [<ffffffff8105ef37>] ?
kthread_worker_fn+0x139/0x139<br>
[ 1201.890804] [<ffffffff81351cf0>] ?
gs_change+0x13/0x13<br>
<br>
and lots of them. With this stack track the CPU load will
just increase and I have to power cycle it to get the system
back. I have added the following sysctls:<br>
<br>
fs.file-max = 262144<br>
kernel.pid_max = 262144<br>
net.ipv4.tcp_rmem = 4096 87380 8388608<br>
net.ipv4.tcp_wmem = 4096 87380 8388608<br>
net.core.rmem_max = 25165824<br>
net.core.rmem_default = 25165824<br>
net.core.wmem_max = 25165824<br>
net.core.wmem_default = 131072<br>
net.core.netdev_max_backlog = 8192<br>
net.ipv4.tcp_window_scaling = 1<br>
net.core.optmem_max = 25165824<br>
net.core.somaxconn = 65536<br>
net.ipv4.ip_local_port_range = 1024 65535<br>
kernel.shmmax = 4294967296<br>
vm.max_map_count = 262144<br>
<br>
but the import part I found out was:<br>
#<a moz-do-not-send="true"
href="http://blog.ronnyegner-consulting.de/2011/10/13/info-task-blocked-for-more-than-120-seconds/"
target="_blank">http://blog.ronnyegner-consulting.de/2011/10/13/info-task-blocked-for-more-than-120-seconds/</a><br>
vm.dirty_ratio=10<br>
<br>
which does not seem to help thou.<br>
<br>
Now some info on the disk:<br>
#mount<br>
/dev/md2 on /data type xfs (rw,noatime,attr2,delaylog,sunit=1024,swidth=4096,noquota)<br>
<br>
cat /proc/meminfo<br>
MemTotal: 132259720 kB<br>
MemFree: 122111692 kB<br>
<br>
cat /proc/cpuinfo (32 v cores)<br>
processor : 31<br>
vendor_id : GenuineIntel<br>
cpu family : 6<br>
model : 45<br>
model name : Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz<br>
<br>
Some info the Host:<br>
# cat /etc/debian_version<br>
wheezy/sid<br>
# uname -a<br>
Linux chaos 3.2.0-3-amd64 #1 SMP Thu Jun 28 09:07:26 UTC
2012 x86_64 GNU/Linux<br>
ii kvm 1:1.1.0+dfsg-3 dummy
transitional package from kvm to qemu-kvm<br>
ii qemu-kvm 1.1.0+dfsg-3 Full
virtualization on x86 hardware<br>
ii libvirt-bin 0.9.12-4
programs for the libvirt library<br>
ii libvirt0 0.9.12-4 library
for interfacing with different virtualization systems<br>
ii python-libvirt 0.9.12-4
libvirt Python bindings<br>
ii opennebula 3.4.1-3+b1
controller which executes the OpenNebula cluster services<br>
ii opennebula-common 3.4.1-3
empty package to create OpenNebula users and directories<br>
ii opennebula-sunstone 3.4.1-3
web interface to which executes the OpenNebula cluster
services<br>
ii opennebula-tools 3.4.1-3
Command-line tools for OpenNebula Cloud<br>
ii ruby-opennebula 3.4.1-3
Ruby bindings for OpenNebula Cloud API (OCA)<br>
<br>
Any ideas on how to get this working right now the server is
a lemon! :0<span class="HOEnZb"><font color="#888888"><br>
<br>
-- <br>
Jurgen Weber<br>
<br>
Systems Engineer<br>
IT Infrastructure Team Leader<br>
<br>
THE ICONIC | E <a moz-do-not-send="true"
href="mailto:jurgen.weber@theiconic.com.au"
target="_blank">jurgen.weber@theiconic.com.au</a> | <a
moz-do-not-send="true"
href="http://www.theiconic.com.au" target="_blank">www.theiconic.com.au</a><br>
<br>
_______________________________________________<br>
Users mailing list<br>
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href="mailto:Users@lists.opennebula.org"
target="_blank">Users@lists.opennebula.org</a><br>
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href="http://lists.opennebula.org/listinfo.cgi/users-opennebula.org"
target="_blank">http://lists.opennebula.org/listinfo.cgi/users-opennebula.org</a><br>
</font></span></blockquote>
</div>
<br>
</div>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Jurgen Weber
Systems Engineer
IT Infrastructure Team Leader
THE ICONIC | E <a class="moz-txt-link-abbreviated" href="mailto:jurgen.weber@theiconic.com.au">jurgen.weber@theiconic.com.au</a> | <a class="moz-txt-link-abbreviated" href="http://www.theiconic.com.au">www.theiconic.com.au</a></pre>
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