Skip to main content

Poor Disk Performance on VMs; Host using PERC H310 RAID 5

I have a Dell R620 running 5 500GB 7.2K RPM SATA 3Gbps
2.5in Hot-plug Hard Drives in a PERC H310 controller (which I am beginning to regret
buying).



I am getting awful read/write speeds
on Linux VMs (Fedora 19, Cent 6 and Ubuntu 12.04) running ESXi 5.0 free license. Using
Thin, Thick or Sparse VMDKs don't make a
difference.



An example
hdparm:



cached reads 9750 MB in
            2.00 seconds = 4877.74 MB/sec
buffered reads: 42 MB in 3.44 seconds = 12.21
            MB/sec



Also
a dd if=/dev/zero of=test bs=1048576 count=2048 (to create an arbitrary 2GB file) took
about a minute and a half!



I have a very similar
host with a software RAID controller that has similar VMs which are much faster in disk
speeds. I didn't set up the RAID, I only manage the server, but IT sets them
up.



The Datastore shows an average 1.189
millisecond latency for reads and a 6.3 millisecond latency for writes. The datastore
shows 1.89 TB so that is about correct for 5 x 500 GB drives in a RAID 5. Initially I
was thinking maybe it isn't using all of the drives. What could be going on? I have
asked IT to take a look at the RAID BIOS and see if there are some diagnostics we can
run.



UPDATE
I
realized the one faster host has 10K RPM disks and the newer one has
7.2K



UPDATE
2

Is it possible that ESXi being run off of a SD
card is causing performance to lag for disk operations within
VMs?

Comments

Post a Comment

Popular posts from this blog

iLO 3 Firmware Update (HP Proliant DL380 G7)

The iLO web interface allows me to upload a .bin file ( Obtain the firmware image (.bin) file from the Online ROM Flash Component for HP Integrated Lights-Out. ) The iLO web interface redirects me to a page in the HP support website ( http://www.hp.com/go/iLO ) where I am supposed to find this .bin firmware, but no luck for me. The support website is a mess and very slow, badly categorized and generally unusable. Where can I find this .bin file? The only related link I am able to find asks me about my server operating system (what does this have to do with the iLO?!) and lets me download an .iso with no .bin file And also a related question: what is the latest iLO 3 version? (for Proliant DL380 G7, not sure if the iLO is tied to the server model)
Post a Comment
Read more

linux - Awstats - outputting stats for merged Access_logs only producing stats for one server's log

I've been attempting this for two weeks and I've accessed countless number of sites on this issue and it seems there is something I'm not getting here and I'm at a lost. I manged to figure out how to merge logs from two servers together. (Taking care to only merge the matching domains together) The logs from the first server span from 15 Dec 2012 to 8 April 2014 The logs from the second server span from 2 Mar 2014 to 9 April 2014 I was able to successfully merge them using the logresolvemerge.pl script simply enermerating each log and > out_putting_it_to_file Looking at the two logs from each server the format seems exactly the same. The problem I'm having is producing the stats page for the logs. The command I've boiled it down to is /usr/share/awstats/tools/awstats_buildstaticpages.pl -configdir=/home/User/Documents/conf/ -config=example.com awstatsprog=/usr/share/awstats/wwwroot/cgi-bin/awstats.pl dir=/home/User/Documents/parced -month=all -year=all...
Post a Comment
Read more

linux - How can I get my mediawiki to stop thinking I have cookies disabled?

I've searched half a day for how to resolve this issue, and can't figure it out. Shortly after I made my wiki a simple private wiki according to the instructions at Mediawiki's website, it started giving me this weird login error message: Wiki uses cookies to log in users. You have cookies disabled. Please enable them and try again. If I remove those private wiki settings, the error disappears, even if I try logging in. But I need it to be a private wiki for only my team. So what do I do? Here's what I've done so far. Just to be safe, after ever change, I try rebooting Apache using: sudo /etc/init.d/apache2 restart In my php.ini file, I have the following set: session.save_path = "/var/lib/php5" session.cookie_secure = secure session.cookie_path = /tmp session.cookie_domain = my server's internal URL (should I even set this? this field was blank before, but not commented out) session.referer_check = Off I ran the following to ensure that the fold...
Post a Comment
Read more