Skip to main content

linux - slow software raid



I've got software raid 1 for / and /home and it seems I'm not getting the right speed out of it.




Reading from md0 I get around 100 MB/sec
Reading from sda or sdb I get around 95-105 MB/sec



I thought I would get more speed (while reading data) from two drives. I don't know what is the problem.



I'm using kernel 2.6.31-18




hdparm -tT /dev/md0




/dev/md0: Timing cached reads: 2078
MB in 2.00 seconds = 1039.72 MB/sec
Timing buffered disk reads: 304 MB in
3.01 seconds = 100.96 MB/sec



hdparm -tT /dev/sda



/dev/sda: Timing cached reads: 2084
MB in 2.00 seconds = 1041.93 MB/sec

Timing buffered disk reads: 316 MB in
3.02 seconds = 104.77 MB/sec



hdparm -tT /dev/sdb



/dev/sdb: Timing cached reads: 2150
MB in 2.00 seconds = 1075.94 MB/sec
Timing buffered disk reads: 302 MB in
3.01 seconds = 100.47 MB/sec





Edit:
Raid 1


Answer



Take a look at the following article at nixCraf, HowTo: Speed Up Linux Software Raid Building And Re-syncing.



It explains the different settings in /proc that can be adjusted to influence the software raid speed. (Not just during building/syncing as the title suggests.)


Comments

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)

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...

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...