<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">I've been looking at linux raid 1 performance, i.e two driver, mirrored.<br><br>Seems that I saw something I was not familiar with <br><br>check dis<br><br><pre> mdadm --create /dev/md2 --chunk=256 -R -l 10 -n 2 -p f2 /dev/sda2 /dev/sdb2<br><br> mkfs -t ext3 /dev/md2<br><br> RAID type sequential read random read sequential write random write<br> Ordinary disk 82 34 67 56<br> RAID0 155 80 97 80<br> RAID1 80 35 72 55<br> RAID10,n2 79 56 69 48<br> RAID10,f2 150 79 70 55<br><br><br>from http://linux-raid.osdl.org/index.php/Performance<br><br>but the
performance is double? what gives..<br><br>I always thought that raid-1 gave a read performance increase?<br>i.e it would read block in alternative drives?<br><br>And raid 10 (mirror+striping), takes 4 drives?<br><br>so, what does f2 do, do I get half the disk space?<br><br>I can't work this out!<br><br><br><br><br></pre><br><br>--- On <b>Fri, 19/6/09, lug@seany.us <i><lug@seany.us></i></b> wrote:<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><br>From: lug@seany.us <lug@seany.us><br>Subject: Re: [dundee] ELF yourself encryption<br>To: "Tayside Linux User Group" <dundee@lists.lug.org.uk><br>Date: Friday, 19 June, 2009, 4:13 PM<br><br><div class="plainMail">I totally agree, software raid is so flexible. I too was stung by the failed controller meaning dataloss.<br><br>Linux md raid 1 has about 1% CPU overhead and you can manage it directly via the commandline (no messing around with
stupid BIOS screens). With CPU speeds these days software raid can easily compete with hardware raid.<br><br>Hardware raid is only really nessesary if you are running something other than RAID1, such as RAID5.<br><br>Of course with most hardware raid solutions you do have the benefit of battery backup on the cache at least.<br><br>Regards,<br>Sean McRobbie<br><br>----- Original Message -----<br>From: "Lee Hughes" <<a ymailto="mailto:toxicnaan@yahoo.co.uk" href="/mc/compose?to=toxicnaan@yahoo.co.uk">toxicnaan@yahoo.co.uk</a>><br>To: "Davidson Kris" <<a ymailto="mailto:Davidson.Kris@gmail.com" href="/mc/compose?to=Davidson.Kris@gmail.com">Davidson.Kris@gmail.com</a>>, "Tayside Linux User Group" <<a ymailto="mailto:dundee@lists.lug.org.uk" href="/mc/compose?to=dundee@lists.lug.org.uk">dundee@lists.lug.org.uk</a>><br>Sent: Friday, 19 June, 2009 15:36:40 GMT +00:00 GMT Britain, Ireland, Portugal<br>Subject: Re: [dundee] ELF yourself
encryption<br><br><br>why? <br><br>the testing I've been doing with it , seems pretty stable to me, <br><br>have you had bad vibes with it chris? <br><br>I once had a hardware raid controller fail on me, and I couldn't get a replacement <br>board, thus I had to wipe the array, and start all over again! <br><br>so, hardware has it advantages, but software is pretty cool too! <br><br>I bet you could even run it over a network...hmmm.network raid! <br><br><br><br><br>--- On Fri, 19/6/09, Kris Davidson <<a ymailto="mailto:davidson.kris@gmail.com" href="/mc/compose?to=davidson.kris@gmail.com">davidson.kris@gmail.com</a>> wrote: <br><br><br><br>From: Kris Davidson <<a ymailto="mailto:davidson.kris@gmail.com" href="/mc/compose?to=davidson.kris@gmail.com">davidson.kris@gmail.com</a>> <br>Subject: Re: [dundee] ELF yourself encryption <br>To: "Tayside Linux User Group" <<a ymailto="mailto:dundee@lists.lug.org.uk"
href="/mc/compose?to=dundee@lists.lug.org.uk">dundee@lists.lug.org.uk</a>>, "Lee Hughs" <<a ymailto="mailto:toxicnaan@yahoo.co.uk" href="/mc/compose?to=toxicnaan@yahoo.co.uk">toxicnaan@yahoo.co.uk</a>> <br>Date: Friday, 19 June, 2009, 3:22 PM <br><br><br>Argh, software raid... Kill it with fire! <br><br>_______________________________________________ <br>dundee GNU/Linux Users Group mailing list <br><a ymailto="mailto:dundee@lists.lug.org.uk" href="/mc/compose?to=dundee@lists.lug.org.uk">dundee@lists.lug.org.uk</a> <a href="http://dundee.lug.org.uk" target="_blank">http://dundee.lug.org.uk</a> <br><a href="https://mailman.lug.org.uk/mailman/listinfo/dundee" target="_blank">https://mailman.lug.org.uk/mailman/listinfo/dundee</a> <br>Chat on IRC, #tlug on dundee.lug.org.uk <br><br><br>_______________________________________________<br>dundee GNU/Linux Users Group mailing list<br><a ymailto="mailto:dundee@lists.lug.org.uk"
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