Displaying 20 results from an estimated 4000 matches similar to: "100% iowait in domU with no IO tasks."
2020 Jul 03
2
Slow terminal response Centos 7.7 1908
Hey!
I have a strange condition in one of the servers that I don't where to
start looking.
I login to the server via SSH (cant doit any other way) and anything that I
type is slow
HTTP sessions timeout waiting for screen redraw. So, the server is acting
"slow".
server is bare metal. no virtual services.
no alarms in the disk raid
note: server was restarted because of power failure.
2020 Jul 03
1
Slow terminal response Centos 7.7 1908
Hi Erick,
what was the value of 'si' in top ?
Best Regards,
Strahil Nikolov
?? 3 ??? 2020 ?. 18:48:30 GMT+03:00, Erick Perez - Quadrian Enterprises <eperez at quadrianweb.com> ??????:
>It was found that the software NIC team created in Centos was having
>issues due to a failing network cable. The team was going berserk with
>up/down changes.
>
>
>On Fri, Jul 3,
2016 May 25
6
Slow RAID Check/high %iowait during check after updgrade from CentOS 6.5 -> CentOS 7.2
I?ve posted this on the forums at https://www.centos.org/forums/viewtopic.php?f=47&t=57926&p=244614#p244614 - posting to the list in the hopes of getting more eyeballs on it.
We have a cluster of 23 HP DL380p Gen8 hosts running Kafka. Basic specs:
2x E5-2650
128 GB RAM
12 x 4 TB 7200 RPM SATA drives connected to an HP H220 HBA
Dual port 10 GB NIC
The drives are configured as one large
2016 May 27
2
Slow RAID Check/high %iowait during check after updgrade from CentOS 6.5 -> CentOS 7.2
All of our Kafka clusters are fairly write-heavy. The cluster in question is our second-heaviest ? we haven?t yet upgraded the heaviest, due to the issues we?ve been experiencing in this one.
Here is an iostat example from a host within the same cluster, but without the RAID check running:
[root at r2k1 ~] # iostat -xdmc 1 10
Linux 3.10.0-327.13.1.el7.x86_64 (r2k1) 05/27/16 _x86_64_ (32 CPU)
2013 Apr 05
0
DRBD + Remus High IO load frozen
Dear all,
I have installed DRBD 8.3.11 compiled from sources. However the backend
block will freeze if there is high IO load. I use Remus to support high
availability and checkpointing is controlled by remus for each 400ms.
If I check the Iostat I got the idle CPU will decreasing extremely each
checkpointing and when its reach 0% of idle cpu the local backing device
will freeze and damage the
2020 Jul 03
0
Slow terminal response Centos 7.7 1908
It was found that the software NIC team created in Centos was having
issues due to a failing network cable. The team was going berserk with
up/down changes.
On Fri, Jul 3, 2020 at 10:12 AM Erick Perez - Quadrian Enterprises <
eperez at quadrianweb.com> wrote:
> Hey!
> I have a strange condition in one of the servers that I don't where to
> start looking.
> I login to the
2016 May 27
0
Slow RAID Check/high %iowait during check after updgrade from CentOS 6.5 -> CentOS 7.2
On 05/25/2016 09:54 AM, Kelly Lesperance wrote:
> What we're seeing is that when the weekly raid-check script executes, performance nose dives, and I/O wait skyrockets. The raid check starts out fairly fast (20000K/sec - the limit that's been set), but then quickly drops down to about 4000K/Sec. dev.raid.speed sysctls are at the defaults:
It looks like some pretty heavy writes are
2016 Jun 01
0
Slow RAID Check/high %iowait during check after updgrade from CentOS 6.5 -> CentOS 7.2
I did some additional testing - I stopped Kafka on the host, and kicked off a disk check, and it ran at the expected speed overnight. I started kafka this morning, and the raid check's speed immediately dropped down to ~2000K/Sec.
I then enabled the write-back cache on the drives (hdparm -W1 /dev/sd*). The raid check is now running between 100000K/Sec and 200000K/Sec, and has been for several
2012 May 16
1
Very High Load on Dovecot 2 and Errors in mail.err.
Hi,
I have a DELL PE R610 (32GB RAM 2x Six Core CPU and about 1,4 TB RAID 10)
running with 20.000 Mailaccounts behind 2 Dovecot IMAP/POP3 Proxies on a Debian Lenny.
The Server was running about 1 year without any problems. 15Min Load was between 0,5 and max 8.
No high IOWAIT. CPU Idletime about 98%.
But since yesterday morning the Systemload on the Server has been increased over 500. I Think
2012 Feb 20
11
btrfs-convert processing time
Hi,
I''m trying to convert two ext4 FS to btrfs, but I''m surprised by the
time needed to do that conversion.
The first FS is on a 500GiB block device, and btrfs-convert is running
since more than 48h :
root 1978 25.6 47.7 748308 732556 ? D Feb18 944:44
btrfs-convert /dev/vg-backup/backup
The second is on a 340GiB block device, and the processing time is similar
2009 Apr 03
35
Xen system hang or freeze
Hi all,
This is my first post to the list, I hope someone out there can help!
I am running xen 3.0.3, with CentOS 5.2 based Dom0
(kernel-xen-2.6.18-92.1.22.el5)
Recently I have noticed some complete system lockups on a few different
servers. Neither Dom0 or any of the guests respond to pings, connecting a
keyboard and monitor to the system only shows a blank screen. Nothing is
written to logs
2007 Oct 18
1
Operations error with AD connections
Hello,
dovecot version: 1.0.beta3-3ubuntu5.5
OS: 2.6.15-26-server i686 GNU/Linux Ubuntu dapper
filesys: ext3
authentication is with ldap (Active Directory)
the problem is that after a while with a number of pop3 connections (8 people
who have checking every 5 minutes), the ldap_search gives 'Operation Error' .
we have tried to use the global catalog, but that doesn't solve the
2008 Aug 18
1
iowait / Perfomance problems with xen on drbd (centos 5.2)
Hi,
we have 2 servers on centos5.2 in a cluster with the redhat cman in the
configuration
SERVER1 > LVM \
CMAN DRBD > XEN
SERVER2 > LVM /
For each xen we create a new local LVM on each node, put them in a drbd
and install an os (debian 4 or ubuntu 8). The xens are running as pvm.
Everything works fine since over 4 months now.
But we have some performance-Problems:
Writing
2009 Aug 06
0
High iowait in dom0 after creating a new guest, with file-based domU disk on GFS
Hopefully I summed up the jist of the problem in the subject line. ;)
I have a GFS cluster with ten Xen 3.0 dom0s sharing an iSCSI LUN. There are
on average 8 domUs running on each Xen server. The dom0 on each server is
hard-coded to 2 CPUs and 2GB of RAM with no ballooning, and has 2GB of
partition-based swap.
When creating a new domU on any of the Xen servers, just after the
completion of
2010 Mar 18
0
Extremely high iowait
Hello,
We have a 5 node OCFS2 volume backed by a Sun (Oracle) StorageTek 2540. Each system is running OEL5.4 and OCFS2 1.4.2, using device-mapper-multipath to load balance over 2 active paths. We are using the default multipath configuration for our SAN. We are observing iowait time between 60% - 90%, sustaining at over 80% as I'm writing this, driving load averages to >25 during an rsync
2016 May 25
1
Slow RAID Check/high %iowait during check after updgrade from CentOS 6.5 -> CentOS 7.2
On 2016-05-25 19:13, Kelly Lesperance wrote:
> Hdparm didn?t get far:
>
> [root at r1k1 ~] # hdparm -tT /dev/sda
>
> /dev/sda:
> Timing cached reads: Alarm clock
> [root at r1k1 ~] #
Hi Kelly,
Try running 'iostat -xdmc 1'. Look for a single drive that has
substantially greater await than ~10msec. If all the drives
except one are taking 6-8msec, but one is very
2012 Jul 11
12
99% iowait on one core in 8 core processor
Hi All,
We have a xen server and using 8 core processor.
I can see that there is 99% iowait on only core 0.
02:28:49 AM CPU %user %nice %sys %iowait %irq %soft %steal %idle intr/s
02:28:54 AM all 0.00 0.00 0.00 12.65 0.00 0.02 2.24 85.08 1359.88
02:28:54 AM 0 0.00 0.00 0.00 96.21 0.00 0.20 3.19 0.40 847.11
02:28:54 AM
2007 Oct 18
1
Vista performance (uggh)
Issue: Vista reads slowly from a samba server. This appears to pop up
periodically here and elsewhere.
My samba.conf file has:
[homes]
...
vfs objects = readahead
As suggested elsewhere.
Writes are approximately 17-18MB/s which is acceptable. Reads are in
the 8MB/s range which is appalingly slow. Using linux smbclient and
windows XP clients I can read at 25+MB/s. I've enabled vfs
2008 Jun 03
6
development machine with xen on gentoo
Hi all.
We just put a relative large server in operation (for our measures ;-)
), a 4x Dual Core / Intel with 16GB Ram and a 3ware 9550SX SATA-RAID
with 4 drives. Operating system for the Dom0 is an up-to-date gentoo linux.
Everything runs really fine, there are 4 Domu''s running, 1x gentoo and
2x debian and 1x Windows Server 2003. DomU''s are running blazing fast in
normal
2006 Jun 07
2
SAR
Folks,
At what point in iowait should I start to worry about having a
bottleneck, or is this something that can't be answerd with a single
integer? According to sar, after my last reboot to turn off
hyperthreading as a test, at one time, I see 4.9% iowait, but then one
minute later, it droped back to 0.01%, and rarely even gets to 1.0%, at
least what I remember from yesterday. ?