similar to: Extremely poor write performance, but read appears to be okay

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

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

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)

Hi, folks, I''m attempting to run an e-mail server on Xen. The e-mail system is Novell GroupWise, and it serves about 250 users. The disk volume for the e-mail is on my SAN, and I''ve attached the FC LUN to my Xen host, then used the "phy:/dev..." method to forward the disk through to the domU. I''m running into an issue with high I/O wait on the box (~250%)

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, I have high IO-Wait on the ods (ceph), the osd are running a v3.1-rc9 kernel. I also experience high IO-rates, around 500IO/s reported via iostat. Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sda 0.00 0.00 0.00 6.80 0.00 62.40 18.35 0.04 5.29 0.00 5.29 5.29 3.60 sdb

Hi 2 all ! I have problems with concurrent filesystem actions on a ocfs2 filesystem which is mounted by 2 nodes. OS=RH5ES and OCFS2=1.2.6 F.e.: If I have a LV called testlv which is mounted on /mnt on both servers and I do a "dd if=/dev/zero of=/mnt/test.a bs=1024 count=1000000" on server 1 and do at the same time a du -hs /mnt/test.a it takes about 5 seconds for du -hs to execute: 270M

we're having a weird disk I/O problem on a 5.4 server connected to an external SAS storage with an LSI logic megaraid sas 1078. The server is used as a samba file server. Every time we try to copy some large file to the storage-based file system, the disk utilization see-saws up to 100% to several seconds of inactivity, to climb up again to 100% and so forth. Here are a snip from the iostat

Am 2015-09-17 09:29, schrieb Pasi K?rkk?inen: > > Are you using nfs over UDP or TCP ? > TCP, but Network cant be the bottleneck, have tested it with iperf between bare metal/domU's and the nfs domU and it was perfectly fast... > > I don't think. > > > If you used NFS over UDP, try running it over TCP. no I use it over TCP... > > What does

Hi all, I just installed centos 5.4 xen-kernel on intel core i5 machine as dom0. After some hours of syncing a raid10 array (8 sata disk) I noticed a steadily increasing loadavg. I think without reasonable i/o wait or cpu utilization the loadavg on this system should be very lower. If this loadavg is normal I would be greatful if somone could explain why. The screenshots below show that there is

Hello, I would really appreciate some help/guidance with this problem. First of all sorry for the long message. I would file a bug, but do not know if it is my fault, dm-cache, qemu or (probably) a combination of both. And i can imagine some of you have this setup up and running without problems (or maybe you think it works, just like i did, but it does not): PROBLEM LVM cache writeback

Here is a sample of running iostat on a server that has a LUN from a SAN with multiple paths. I am specifying a device list that just grabs the bits related to the multi path device: $ iostat -dxkt 1 2 sdf sdg sdh sdi dm-7 dm-8 dm-9 Linux 2.6.18-371.8.1.el5 (db21b.den.sans.org) 06/20/2014 Time: 02:30:23 PM Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await

I just installed CentOS 5.4 64 bit release on a 1.9ghz CPU with 8gB of RAM. It has 2 Western Digital 1.5TB SATA2 drives in RAID1. [root at server ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/md2 1.4T 1.4G 1.3T 1% / /dev/md0 99M 19M 76M 20% /boot tmpfs 4.0G 0 4.0G 0% /dev/shm [root at server ~]# Its barebones

Hi, I'm running a CentOS 4. server and I sometimes face a weird problem. It is a weird performance problem, and here is how I discovered it. This server runs OpenVZ virtual machines, and one of them is an asterisk server for my personal use. The first symptom of the problem is that the voice quality became flaky. So I logged on the server to see what could be eating cpu cycles, when I

Op 29-01-15 om 00:00 schreef Gordon Messmer: > On 01/28/2015 12:12 PM, Patrick Bervoets wrote: >> >> ARPING 192.168.1.15 from 0.0.0.0 br0 >> Unicast reply from 192.168.1.15 [AC:16:2D:72:67:D4] 0.723ms >> Sent 1 probes (1 broadcast(s)) >> Received 1 response(s) >> >> Thanks anyway > > I'm not sure what you mean by "thanks anyway".

Hi All I have xeon server with 16 Gb Ram and no Swap memory.I am running cassandra server on two node in cluster.When there is high load on server kswapd0 kicks inn and take 100% cpu and make machine very slow and we need to restart out cassandra server.I have latest kernel 2.6.18-238.9.1.el5.Please let me know how can i fix this issue .Its hurting us badly this our production server any

Hi, I have a problematic CentOS XEN server and hope someone could point me in the right direction to optimize it a bit. The server runs on a Core2Quad 9300, with 8GB RAM (max motherboard can take, 1U chassis) on an Intel motherboard with a 1TB SATA HDD. dom0 is set to 512MB limit with a few small XEM VM's running: root at zaxen01:[~]$ xm list Name ID

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

We are struggling with a strange problem. When we have some VMWare clients running (mostly MS windows clients), than the IO-write performance on the host becomes very bad. The guest os's do not do anything, just having them started, sitting at the login prompt, is enough to trigger the problem. The host has plenty of 4G of RAM, and all clients fit easily into the space. The disksystem is a

I?m looking for advice and considerations on how to optimally setup and deploy an NFS-based home directory server. In particular: (1) how to determine hardware requirements, and (2) how to best setup and configure the server. We actually have a system in place, but the performance is pretty bad---the users often experience a fair amount of lag (1--5 seconds) when doing anything on their home