- To: David Kempe <dave@xxxxxxxxxxx>
- Subject: Re: [SLUG] RAID and LVM
- From: Brett Coady <bc1968au@xxxxxxxxxxxx>
- Date: Fri, 19 Feb 2010 20:05:27 -0800 (PST)
- Cc: slug@xxxxxxxxxxx
- Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com.au; s=s1024; t=1266638727; bh=bW34ezgwR4YFQNGLZUGU2HwhZiPiQZ5umK6ZVle7NRs=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=jHP7qeoNUEALpDJn++GUL/UFkkwy+5ZlM5OF4DgAdky0WqS2J50ob1zignKbyyFwPJlkF6rWHgWvCeAEJbGJEE11LSnESXdbYQD2x7ucroZHYzWSN43pDsZwpoOqI4AGhiH7BPsYqvPSvn/SeK1/uYc6kFKvUrgOs9TEz0mvWtA=
- Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=e8duJ4fpoOlrysfoW9F35sL/J2cBywr4IaFIc19KtIDCs9tajjybWvUrvZQCrAcB2gqd6tU2rNfXi1ECopNtgcHhdhDiST19DsTN701JpWoJcYUTAr4vEQBtbGfsKXqh82abdww+PtrrlF0woauK5KQtmbU0Vy0HD21u5P4RDmg=;
>
>From: David Kempe <dave@xxxxxxxxxxx>
>To: Brett Coady <bc1968au@xxxxxxxxxxxx>
>Cc: "slug@xxxxxxxxxxx" <slug@xxxxxxxxxxx>
>Sent: Sat, 20 February, 2010 12:20:43 PM
>Subject: Re: [SLUG] RAID and LVM
>
>
>
>
>On 20/02/2010, at 11:53 AM, Brett Coady <bc1968au@xxxxxxxxxxxx> wrote:
>
>
>>>
>>The trouble with Bonnie and IOzone is that they test the filesystem , for my example I was looking at the raw disk speed for raid results.
>>
>>
>
>
>Well if you keep the kernel and filesystem identical between runs you end up benchmarking the hardware. Still useful for the purpose of comparision.
That is true , however the original poster was asking about RAID and partitioning , He hadn't mention
File-systems and that's is why I did the benchmarking the way I did to try and shed some light on Raid gains/loses and speed.
>
>
>>>
>>I have since that learnt that some Motherboard backup the BIOS to the end HDD and have a setting to do so. My motherboard has no option for this and has dual BIOS anyway but it still appears to do it!
>>
>
>The difference in drive size is not the dual bios at all. And leaving a buffer at the end of drives when using software raid is a good idea cos diffrences in drive geometry will always happen.
>
Are you sure about this, I spent quite a bit of time trying to work out where my missing 1MB had gone?
On initial Boot the Drives had exactly the same size on both.
Also to try and test the problem I actually swapped the drives over and guess what, I lost 1 MB from the opposite drive! (yeah I checked the electronic serial numbers)
Ahhh, Upon further investigation I find something interesting and I am not alone!
http://en.wikipedia.org/wiki/Host_protected_area
An application called Sleuthkit tells me more.
This is handy to know for someone setting RAID up,
they even give examples on how to remove stubborn HPA
regards
Brett
SLUG Mailing List Archives