Server :: Disparity In IOPS Between Sar And IOStat?
Jul 19, 2011
I have a RHEL5 server that hosts an apache SSL proxy and about 20 tomcat instances. As of late we've had latency issues on the system that I can't pin down. In trying to diagnose whether the local HD is being over-utilized, I started gathering disk utilization stats using iostat and sar. For Sar, I'm using the "tps" metric, and for IOStat I'm combining reads and writes per second for the raw disk device, sda. When I put the stats into excel, the profile of the graphed data points match up for the most part, but sar is reporting the values for the same data points as being many magnitudes higher. Can anybody give me a hint as to why one tool would report the same data differently when (as far as I know) both of them pull their disk I/O stats from the same place?
In my production setup, i have 3 servers using the same mount point. However, i see that the IOPS is low. Does this kind of architecture have any impact on IOPS. In case it is neutral, how can i tune my setup for better IOPS.
I want to virtualize some servers but need to figure out what their current IOPS are. I only have CLI access to the servers. Does anyone know how to do this?
For a while my root partition has been filling up for no apparent reason. I I have been deleting things to find out it fills up again in a mater of days. To make it more 'interesting', there is a disparity between what I get from df and what the du command is telling me. After dismounting the other file systems and turning off applications, this is what i get:
du claims that I'm using 29G on that partition, which sounds about right (this is my OS and basic /home partition, everything else is elsewhere). df on the other hand is telling me here that out of 69G, 64G are in use with only 54M left.
calculating the IOPS for my system ?I had understood that IOPS could be calculated by monitoring IOSTAT. The r/s (reads/sec) and w/s (write/sec) combined basically gave you the peak IOPS.However having monitored iostat for my app during a performance test, the figures I'm seeing lead me to believe that iostat couldn't be a reliable way to calculate IOPS. I get values of over 10,000 for w/s! I didn't think this was possible given the storage system i have (4 x 7500rpm sata disks in raid 5).
I need to write a wrapper script for iostat functionality . in solaris unix i have iostat but in linux i don't have iostat , so I need to write a wrapper script which does all the functionality of iostat . i am entirely new to scripting
Trying to understand grep,sed,awk but maybe its too early for me and also i suspect iostat is not the correct program for exactly what i'm looking for...The goal is to print only the current read and write speeds of the disk, represented in a numerical value with two separated commands. So for example when writing a file to disk from an external disk, the value reflects the speed of the process.
"iostat -dk sda" prints Code: Linux 2.6.38 (Infidel) 07/30/2011 _x86_64_ (4 CPU)
I use this machine as a samba server with one small IDE hdd for system and one large SATA hdd (1.5TB) hooked via 4xSATA PCI card. The machine has 1.5GB RAM, and is also to run 2 ktorrent clients inside two Xvncs.The problem is, that even when ktorrent is doing nothing I observe A LOT of hdd activity to the point where movies or even mp3s stored on this server played via samba on a windows machine "stutter". E.g. smplayer will repeat 5 second piece a few times before moving on to the next piece... and it goes on for a good 10 minutes, once it starts.Even browsing directories is slow to the point where it takes 5-20 seconds to show the content in Total Commander (equivalent of Midnight Commander for windows).I am not sure how I can track what is really happening. Why would ktorrent clients create a massive I/O when there's virtually no traffic to/from them? (I have total of 1kB/s down and 10kB/s up while taking the masurements below).Or is there something wrong with the hdd? I had to send back the first one I got, it had plenty of bad sectors (this one does not though, as far as I can tell no data loss occured, just performance sucks).Here's some diagnostic data, please let me know if there's anything else I should check.
I have installed a linux server in my office to run 16 machines. Its main use will be a internal mail server but will be also running websites.
I have installed Ubuntu 9.10 server x64 and have got apache running.
I am looking for the simplest more robust solution for smtp, pop3 and imap. I have only ever used qmail before and found it a pain to configure and its getting old so I though I should probably try something new. I have not much experience with running pop3 or imap on linux so would love a suggestion on that.
have to create a webhost on an running fedora server which runs multiple webpages + a coldfusion serveri have to add an coldfusion virtual host to these.what i would do:*crate a new user & group*enter vhosts.conf and copy an existing host and modify it for the new one.*create an new folder and copy the main files (phpstarter and webroot) *chown the files for the right useri think an apache graceful would be needet
Right now i have a HP DL 180 Server with 130 Gb Hard Disk & 8 Gb ram after Raiding0+1. i want to configure Domain Controller Server for my office for 200 to 300 Users. what should the partition size must be mentioned in my 130 Gb Hard Disk, is that going to be Sufficient for ME ?
i am bit confused about /Usr /Var /Boot partitions, as i need to manage perfectly in 130 GB
if i go with 4 Gb swap and remaining for " / " is that will be fine ? should i need to specify partition sizes separately for / tmp /var / usr ..
I'm running a linux cloud server with the following config 1.2ghz Processor allocation 752MB Ram
The site loads slow and clicking a link almost freezes the page for a second. Also, the page loads could be much faster. We've been running mysqltuner and have pretty much optimized all slow queries. Is there anything we can do to fine tune the server for faster and more responsive?
iam trying to sync file server data into backup server machine by command- rsync -avu path/of/data ipaddress-of-backup-server:/path/where/to/save after running it ask for root password and manually it is successful.but i want to make it automatic.for that i also tried cronjob and also generated authentication key but iam not successful in login automatically..anybody know how to authenticate root to login for storing data in backup server.
I will be relocating to a permanent residence sometime in the next year or two. I've recently begun thinking about the best way to implement a home-based network. It occurred to me that the most elegant solution might be the use of VM technology to eliminate as much hardware and wiring as possible.My thinking is this: Install a multi-core system and configure it to run several VMs, one each for a firewall, a caching proxy server, a mail server, a web server. Additionally, I would like to run 2-4 VMs as remote (RDP)workstations, using diskless workstations to boot the VMs over powerline ethernet.The latest powerline technology (available later this year) will allow multiple devices on a residential circuit operating at near gigabit speed, just like legacy wired networks.
In theory, the above would allow me to consolidate everything but the disklessworkstations on a single server and eliminate all wired (and wireless) connections except the broadband connection to the Internet and the cabling to the nearest power outlets. It appears technically possible, but I'm not sure about the various virtual connections among VMs. In theory, each VM should be able to communicate with the other as if it was on the same network via the server data bus, but what about setting up firewall zones? Any internal I/O bandwidth bottlenecks? Any other potential "gotchas", caveats, issues? (Other than the obvious requirement of having enough CPU and RAM).Any thoughts or observations welcome, especially if they are from real world experience in a VM environment. BTW--in case you're wondering why I'm posting here, it's because I run Debian on all my workstations/servers (running VirtualBox as a VM for Windows XP on one workstation).
I have got a running mail server on CentOS5.4 Final using Zimbra free edition. . Assume that domain is organization.com.local And it is running fine with users created and bugzilla running on the same machine can send mails using this server. But it can obviously send messages to the internal users. There is this option to configure it to use external mail server to send mails outside the network but my external smtp server needs an authentication.Is it possible to configure it this way to use my external server to send mails from internal domain to say gmail?
i recently installed apache2 mysql php exc. to run a realtime stat site for my servers.the only thing is that the buttons/ images are not showing up.i checked that my GD was up to date and installed perl5 GD. dont know what else to check.my site with problems go to:http://24.20.177.228/stats_public
I am working on linux server with below specifications.Linux EDT 2008 i686 i686 i386 GNU/LinuxWhile checking the status of the server using the command 'opmnctl status' and when server is down the output is not getting redirected to file.I m using the command as,opmnctl status > abc.txt.
i have been trying to complete the following project1) Configure a FTP server where we can upload and download files.........2) server must run at 9 pm & stop at 9 am automatically ............although the first task was easy ,i have no idea how to accomplish the 2nd task(not to mention I'm a new user)
I've two internet based server ( xx.xx.xx.xx and yy.yy.yy.yy ) The Y server is running VNC server and is responsible for answering to VNC sessions. But I need to hide the IP of Y server so I want X server to be as VNC Proxy and redirect all VNC sessions to Y server.
I guess the best way is to use iptables but actually I can't get it working so
I'm trying to setup RAID 1 on a CentOS 5 server for a zimbra email server.I get a partion schema error. Can I do this?The server is a HP Proliant ML150 G3 server with two 80GB HDD.
i am trying to send malformed string into ability ftp server in order to have some unexpected crashes. i login in into the ability ftp server on my window 7.On my virtual machine,i am working on a backtrack 4, i tried to send some string to have some unexpected crashes, but i couldn't success.here is the code:
I have installed the Apache, PHP and MYSQL in the rackspace cloud server environment. Can anyone please guide me How can I configure email server in that with postfix or some other with multiple domain.
how do i able to allow some users that are able to create content in directory of http server. For example: i have configured a web server which have default document root /var/www/html, now i want to extend my web server through virtual hosting , i have enable virtual hosting, but i want that user sumit is able to create content in /var/www/html/secret. which is the document root for my virtual site?
I installed IBSng in ubuntu-server .but i can not start this server :Code:[root@myserver]# /etc/init.d/IBSng start.: 8: Can't open /etc/rc.d/init.d/functions"functions" file is in RPM base system . and ubuntu have not this file
I have succesfully installed Postfix mail server in my linux machine(using RHEL 5) but unable to communicate through mails from my linux machine to my windows machine(Windows2003 server). What are the possible configuration steps that i need to configure on my windows machine
I did a basic installation of Debian, which will be used for a mail server. I Installed the bind9 and did the configuration of the zones and created the files in the directory / etc / bind. After the process I typed the following command to test my DNS:
nslookup mail.hotelpart.com and presented the following error:
Easier to stay I put my files in message: The files named.conf, db.hotelpart.com and db.111.20.11.200.
