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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Most of the array vendors out there allow
for SSDs these days. They generally propose something like SSDs for the most
performance sensitive data, fibre drives for somewhat performance sensitive
data and ATA drives for the rest all in the same array.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Also there’s companies selling PCI
boards that are SSDs so you can just add one to an existing server that doesn’t
support SSDs otherwise. Check out a company called RamSan for those and some
fairly good whitepapers.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>One problem with SSDs is they use flash
which degrades over time. RamSan says they have an algorithm that directs
which bits are written where so balances this to extend the life of the SSD.
I saw similar discussion (maybe even the same one) at a presentation at AUUG
last year but have since lost the literature for that.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>RamSan says they also make RAM based
systems that don’t have that problem.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
ale-bounces@ale.org [mailto:ale-bounces@ale.org] <b><span style='font-weight:
bold'>On Behalf Of </span></b>Greg Clifton<br>
<b><span style='font-weight:bold'>Sent:</span></b> Thursday, April 22, 2010
3:00 PM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">Atlanta
Linux Enthusiasts - Yes! We run Linux!</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [ale] XFS on Linux -
Is it ready for prime time?</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>Any feedback on the SSD
question? They are inherently more reliable (by at least an order of
magnitude), no? Read and Write Performance is going up as well as capacities,
and prices are coming down. A multi TB SSD array is probably not something that
most of us could afford to park at home just yet, but maybe in another 2-5 yrs?<br>
<br>
GC<o:p></o:p></span></font></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>On Thu, Apr 22, 2010 at 2:44 PM, Greg Freemyer <<a
href="mailto:greg.freemyer@gmail.com">greg.freemyer@gmail.com</a>> wrote:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Jim,<br>
<br>
Linux mdraid supports 3 drive mirrors. You should have similar write<br>
performance to a 2 drive mirror and improved read-performance.<br>
<br>
So if your using mdraid, you might want to consider raid 10 with 3<br>
drive mirrors, and maybe one hot spare for the whole array.<br>
<br>
Greg<o:p></o:p></span></font></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
On Thu, Apr 22, 2010 at 2:26 PM, Jim Kinney <<a
href="mailto:jim.kinney@gmail.com">jim.kinney@gmail.com</a>> wrote:<o:p></o:p></span></font></p>
</div>
<div>
<div>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>> RAID 5 was an
invention for a time when hard drives were total crap tons of<br>
> money. The pain of losing a drive in a RAID 5 array is just no longer<br>
> balanced by the cost of the drives. If a 1TB drive is only $100, it's<br>
> bluntly dirt cheap now to have a hot spare in a 4 active drive RAID 10<br>
> system. The recovery is much easier and faster when checksums don't have
to<br>
> be calculated for every stinking block on the drive(s).<br>
><br>
> My ideal rig: Striped array for speed composed of mirrored triplets - 2<br>
> active, one hot spare per active pair.<br>
><br>
> On Thu, Apr 22, 2010 at 1:05 PM, Greg Clifton <<a
href="mailto:gccfof5@gmail.com">gccfof5@gmail.com</a>> wrote:<br>
>><br>
>> Shift in focus to the hardware side of the equation. This thread<br>
>> concentrates on software generated corruption issues, but I have some<br>
>> hardware related questions. First, with RAIDed hard drives, are any
file<br>
>> systems more or less likely to cause (or minimize) the likelihood of<br>
>> corruption of the array and if so, why? Second Greg F (and others)
have<br>
>> commented on NOT using RAID 5 (and RAID 6) esp. with large hard
drives.<br>
>> Looks like 1 or 2 TB hard drives will soon be "standard
issue" for<br>
>> everything but notebook computers. So does that mean that RAID should
be<br>
>> considered 'dead,' except for 0, 1, 10? Third, would SSDs solve the
failure<br>
>> from bad sector issues with HDDs and thus be safe for RAID 5/6<br>
>> implementations?<br>
>><br>
>><br>
>> On Thu, Apr 22, 2010 at 9:41 AM, Ed Cashin <<a
href="mailto:ecashin@noserose.net">ecashin@noserose.net</a>> wrote:<br>
>>><br>
>>> On Wed, Apr 21, 2010 at 9:34 PM, Doug McNash <<a
href="mailto:dmcnash@charter.net">dmcnash@charter.net</a>> wrote:<br>
>>> ...<br>
>>> > Does anyone out there use xfs? How about a suggestion for a
stable<br>
>>> > replacement.<br>
>>><br>
>>> If you use the xfs in the mainline kernel, it's a crap shoot
because<br>
>>> of the amount of churn in the code, but<br>
>>> if you use a long-term kernel like 2.6.16.y, 2.6.27.y, or the
kernels<br>
>>> maintained by distros, then it ought to be stable (as long as the<br>
>>> distro has enough of a user base for other people to find the xfs<br>
>>> bugs first).<br>
>>><br>
>>> --<br>
>>> Ed Cashin <<a href="mailto:ecashin@noserose.net">ecashin@noserose.net</a>><br>
>>> <a href="http://noserose.net/e/" target="_blank">http://noserose.net/e/</a><br>
>>> <a href="http://www.coraid.com/" target="_blank">http://www.coraid.com/</a><br>
>>> _______________________________________________<br>
>>> Ale mailing list<br>
>>> <a href="mailto:Ale@ale.org">Ale@ale.org</a><br>
>>> <a href="http://mail.ale.org/mailman/listinfo/ale" target="_blank">http://mail.ale.org/mailman/listinfo/ale</a><br>
>>> See JOBS, ANNOUNCE and SCHOOLS lists at<br>
>>> <a href="http://mail.ale.org/mailman/listinfo" target="_blank">http://mail.ale.org/mailman/listinfo</a><br>
>><br>
>><br>
>> _______________________________________________<br>
>> Ale mailing list<br>
>> <a href="mailto:Ale@ale.org">Ale@ale.org</a><br>
>> <a href="http://mail.ale.org/mailman/listinfo/ale" target="_blank">http://mail.ale.org/mailman/listinfo/ale</a><br>
>> See JOBS, ANNOUNCE and SCHOOLS lists at<br>
>> <a href="http://mail.ale.org/mailman/listinfo" target="_blank">http://mail.ale.org/mailman/listinfo</a><br>
>><br>
><br>
><br>
><br>
> --<br>
> --<br>
> James P. Kinney III<br>
> Actively in pursuit of Life, <st1:City w:st="on"><st1:place w:st="on">Liberty</st1:place></st1:City>
and Happiness<br>
><br>
><br>
> _______________________________________________<br>
> Ale mailing list<br>
> <a href="mailto:Ale@ale.org">Ale@ale.org</a><br>
> <a href="http://mail.ale.org/mailman/listinfo/ale" target="_blank">http://mail.ale.org/mailman/listinfo/ale</a><br>
> See JOBS, ANNOUNCE and SCHOOLS lists at<br>
> <a href="http://mail.ale.org/mailman/listinfo" target="_blank">http://mail.ale.org/mailman/listinfo</a><br>
><br>
><br>
<br>
<br>
<o:p></o:p></span></font></p>
</div>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>--<o:p></o:p></span></font></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Greg Freemyer<br>
Head of EDD Tape Extraction and Processing team<br>
Litigation Triage Solutions Specialist<br>
<a href="http://www.linkedin.com/in/gregfreemyer" target="_blank">http://www.linkedin.com/in/gregfreemyer</a><br>
CNN/TruTV Aired Forensic Imaging Demo -<br>
<a
href="http://insession.blogs.cnn.com/2010/03/23/how-computer-evidence-gets-retrieved/"
target="_blank">http://insession.blogs.cnn.com/2010/03/23/how-computer-evidence-gets-retrieved/</a><br>
<br>
The Norcross Group<br>
The Intersection of Evidence & Technology<o:p></o:p></span></font></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><a href="http://www.norcrossgroup.com" target="_blank">http://www.norcrossgroup.com</a><o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
_______________________________________________<br>
Ale mailing list<br>
<a href="mailto:Ale@ale.org">Ale@ale.org</a><br>
<a href="http://mail.ale.org/mailman/listinfo/ale" target="_blank">http://mail.ale.org/mailman/listinfo/ale</a><br>
See JOBS, ANNOUNCE and SCHOOLS lists at<br>
<a href="http://mail.ale.org/mailman/listinfo" target="_blank">http://mail.ale.org/mailman/listinfo</a><o:p></o:p></span></font></p>
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<o:p></o:p></span></font></p>
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