search for: iowaits

Hi. I entered one of our domU tonight and see following problem: # iowait -k 5 avg-cpu: %user %nice %system %iowait %steal %idle 0.00 0.00 0.00 100.00 0.00 0.00 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda1 0.00 0.00 0.00 0 0 sda2 0.00 0.00 0.00 0

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

Hi, I am currently running a 10 Node OCFS2 Cluster (version 1.3.9-0ubuntu1) on Ubuntu Server 8.04 x86_64. Linux n1 2.6.24-24-server #1 SMP Tue Jul 7 19:39:36 UTC 2009 x86_64 GNU/Linux The Cluster is connected to a 1Tera iSCSI Device presented by an IBM 3300 Storage System, running over a 1Gig Network. Mounted on all nodes: /dev/sdc1 on /cfs1 type ocfs2

Hello. We have a number of Xen 3.4.2. boxes which have constant iowaits at around 10% with spikes up to 100% when accessing data over NFS. We have been unable to nail down the issue. Any advice? System info: release : 2.6.18-194.3.1.el5xen version : #1 SMP Thu May 13 13:49:53 EDT 2010 machine : x86_64 nr_cpus...

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

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.

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

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)

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

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

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. ?

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

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

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,

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

Just came in from Bugzilla ... Subject: [Bug 121434] Extremely high iowait with 3Ware array and moderate disk activity https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=121434 ------- Additional Comments From thomas.oulevey at elonex.ch 2005-07-29 08:55 EST ------- Hello, About the Linux 2.4 driver, we realized that we have big problem with the 9.2 driver. The 9.1.5.2 was fine. In fact the

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

Kelly Lesperance wrote: > 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

Kelly Lesperance wrote: > 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

What is the HBA the drives are attached to? Have you done a quick benchmark on a single disk to check if this is a raid problem or further down the stack? Regards, Dennis On 25.05.2016 19:26, Kelly Lesperance wrote: > [merging] > > The HBA the drives are attached to has no configuration that I?m aware of. We would have had to accidentally change 23 of them ? > > Thanks, >