<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=Content-Type content="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 11 (filtered medium)">
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Verdana;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman";}
a:link, span.MsoHyperlink
{color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{color:purple;
text-decoration:underline;}
p.MsoPlainText, li.MsoPlainText, div.MsoPlainText
{margin:0in;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:Verdana;
color:blue;
font-weight:normal;
font-style:normal;
text-decoration:none none;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 77.95pt 1.0in 77.95pt;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=EN-US link=blue vlink=purple>
<div class=Section1>
<p class=MsoPlainText><font size=2 color=blue face="Courier New"><span
style='font-size:10.0pt;color:blue'>Hi Guys,</span></font><o:p></o:p></p>
<p class=MsoPlainText><font size=2 color=blue face="Courier New"><span
style='font-size:10.0pt;color:blue'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=blue face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:blue'>This is my first post
on mailing list and would like to have your suggestions on this. <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>I'm contemplating setting up a varnish cache on a system with SSD
drives.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>The obvious benefit is that these systems have great READ speeds and I
expect my hit ratios to be fairly high.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Let's assume I can put 7 SSDs in to a RAID configuration. (there are
some cases that will let me pack in much much more)<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Implementation questions:<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Should I use RAID0? (I expect a drive to fail eventually, so this seems
dangerous.)<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Should I use RAID10? (This halves my disk footprint, which is costly.)<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Should I use RAID5? (SSDs are known to have "bad" write
performance and write limits, and all the extra parity writes may slow this
down considerably.)<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Should I just treat each disk as it's own squid datastore? (how well
does squid handle multiple data stores? and what happens if/when one fails?)<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Should I ignore datastores and just make the SSDs in to large SWAP
partitions and let the linux VM do it's thing? (seems sloppy)<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Any advice from you using SSDs in production environments would be
greatly appreciated. (esp if you're using them for HTTP caches)<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Also how difficult it is for a varnish cache to allow users manage data
life cycle policy from SSD/NAND flash drives to disk. There is an open source
project on Online Hierarchical Storage Manager (OHSM) (e.g.
http://code.google.com/p/fscops/) which i am on verge of trying bt havent
succeeded yet.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Awaiting for your reply on this!!!!<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Regards,<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'> Anand Shah<font color=blue><span style='color:blue'><o:p></o:p></span></font></span></font></p>
</div>
</body>
</html>