This is a multi-part message in MIME format.
------_=_NextPart_001_01C45241.C0EF5F44
Content-Type: text/plain;
charset="US-ASCII"
Content-Transfer-Encoding: quoted-printable
Disk staging is good for the right reasons and for the right backups,
but everything going to disk for backup is like paying one credit card
off with another credit card. At some point you need to get some or all
of that data on tape for portability. =20
=20
If what you are trying to do is address reliability, speed and
portability, then look at the purposed built backup devices such as
Virtual Tape Libraries that support an embedded path to tape. They will
provide the speed of disk, RAID reliability through the convenient
presentation of tape and tape libraries. There are quite a few on the
market now which is great for you because you have so many
choices...just make sure you are choosing for the right reasons.
=20
My suggestion when considering to use "disk" in your backup
infrastructure is to FIRST identify the top three to five reasons you
are looking to address your backup problems with "disk". =20
=20
Second ask yourself if tape is an important factor for your protection
strategy? If tape is not important to your particular strategy there
are many vendor solutions out there that imitate tape but end in disk.
Otherwise, the list narrows considerably as you find those solutions
that support an embedded path to tape.
=20
However, if tape is important then your paradigm for backup shifts a
little bit to the number of hours needed to create tapes during the
"export or eject" window with the VTL's (that is time to create physical
tapes via the embedded path to tape). So doing the math helps a ton
here.
=20
Thirdly and probably most importantly, does it appear on VERITAS'
Support matrix?
=20
Create a punch list and ask questions...hard questions of the
vendors...and get the right solution for the right reasons.
=20
David
=20
BTW: you can check ADIC's offering at http://www.adic.com/gopathlightvx
=20
David A. Chapa * Technical Advisor * ADIC * 720.249.5836 * 720.272.8452
cell * david.chapa AT adic DOT com <mailto:david.chapa AT adic DOT com>=20
HIGH PERFORMANCE, SCALABLE, RELIABLE - http://www.adic.com/gopathlightvx
<http://www.adic.com/gopathlightvx>=20
-----Original Message-----
From: veritas-bu-admin AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu] On Behalf Of Nash, Ebon
Sent: Wednesday, June 09, 2004 11:26 AM
To: 'Johnny Oestergaard'; Paul Esson; veritas-bu AT mailman.eng.auburn DOT edu
Subject: RE: [Veritas-bu] Disk Based Backup
=20
We moved from disk storage units to disk staging storage units and took
a huge performance hit. The overhead required for disk staging, and
apparent filesystem fragmentation due to 100% utilized filesystems,
forced us to revert back to disk storage units. If performance is an
issue, be wary of disk staging storage units.
=20
=20
Ebon Nash
Compuware Corp.
-----Original Message-----
From: veritas-bu-admin AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu]On Behalf Of Johnny
Oestergaard
Sent: Wednesday, June 09, 2004 12:41 PM
To: Paul Esson; veritas-bu AT mailman.eng.auburn DOT edu
Subject: Re: [Veritas-bu] Disk Based Backup
Regarding speed on disk compared to tape I would say that
high-speed tapedrives are much faster then disk except for the time it
takes to load and unload the tape. When the tape is at the right
position tapes are fast. Our 9940B should be able to take around 70 MB/s
if we could feen them that fast. I would like to see a SATA disk system
that could take the same load as just 4 of the 9940B drives.
In an installation using diskstaging I see one great thing that
I think we will use and that is most of all to stage small backups and
slow backups to disk and then let NBU stage them to tape. With a little
luck we should be able to bring our multiplexing down and thereby speed
tapeduplication up.
=09
What makes tapeduplication slow is most of all on duplexed
tapes. We run some tests on duplication speed on backups that where not
duplexed some years ago, and as I remember it we did this at almost the
max speed of the drives (We did 3 tests on 9940A drives)
=09
I would use vault to make my off-site copies
=09
/johnny
=09
At 17:24 09-06-2004 +0100, Paul Esson wrote:
=09
=09
Folks,
=20
I am currently deliberating over disk based backup options and
would welcome comments from those with first hand experience. =20
=20
Specifically, I am trying to way up the pros and cons of using a
Virtual Tape Library versus sharing storage out to media servers from
say a SATA disk array. The latter looks attractive particularly since
the introduction in v5.0 of Disk Staging Storage Units (DSSUs). Is
anyone using DSSUs currently? With VTL there seems to be the cost issue
of licensing drives as in a regular library.
=20
What I would like to do is write all backups initially to disk
but then stage the full backups to tape. I had hoped to create two tape
copies one to remain onsite (in a tape library) and the other to go
offsite. However, I am somewhat confused as to the NetBackup
functionality required to achieve this? If I use the DSSU the data
appears to be migrated to tape as part of the policy anyway, but how
would I achieve my twin copies on tape, ideally with different retention
levels? Do I actually require to use inline copy or even Vault
(duplication) to achieve my end? The concern I have with inline copy is
that the quicker write to disk will be negated by having to write to
tape at the same time and before the job completes. As for Vault I
don't know the product at all but believe it is licensed by drive (How
does this work if your source is a disk storage unit?) and that could
prove costly. I have also read on this list adverse comments about
duplication speeds, although I would be writing from disk to tape.
=20
All comments on any of these items very welcome.
=20
Regards,
=09
Paul Esson
Senior Support Engineer
Redstor Limited
=09
Direct: +44 (0) 1224 595381
Mobile: +44 (0) 7766 906514
E-Mail: paul.esson AT redstor DOT com
Web: www.redstor.com <http://www.redstor.com/>=20
=09
REDSTOR LIMITED
Torridon House
73-75 Regent Quay
Aberdeen
UK
AB11 5AR
=09
Disclaimer:
The information included in this e-mail is of a confidential
nature and is intended only for the addressee. If you are not the
intended addressee, any disclosure, copying or distribution by you is
prohibited and may be unlawful. Disclosure to any party other than the
addressee, whether inadvertent or otherwise is not intended to waive
privilege or confidentiality.<?xml:namespace prefix =3D o ns =3D
"urn:schemas-microsoft-com:office:office" />
=20
The contents of this e-mail are intended for the named addressee only.
It contains information that may be confidential. Unless you are the
named addressee or an authorized designee, you may not copy or use it,
or disclose it to anyone else. If you received it in error please notify
us immediately and then destroy it.=20
------_=_NextPart_001_01C45241.C0EF5F44
Content-Type: text/html;
charset="US-ASCII"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html xmlns:o=3D"urn:schemas-microsoft-com:office:office" =
xmlns:w=3D"urn:schemas-microsoft-com:office:word" =
xmlns:st1=3D"urn:schemas-microsoft-com:office:smarttags" =
xmlns=3D"http://www.w3.org/TR/REC-html40";>
<head>
<meta http-equiv=3DContent-Type content=3D"text/html; =
charset=3Dus-ascii">
<meta name=3DProgId content=3DWord.Document>
<meta name=3DGenerator content=3D"Microsoft Word 10">
<meta name=3DOriginator content=3D"Microsoft Word 10">
<link rel=3DFile-List href=3D"cid:[email protected]">
<o:SmartTagType =
namespaceuri=3D"urn:schemas-microsoft-com:office:smarttags"
name=3D"country-region"/>
<o:SmartTagType =
namespaceuri=3D"urn:schemas-microsoft-com:office:smarttags"
name=3D"City"/>
<o:SmartTagType =
namespaceuri=3D"urn:schemas-microsoft-com:office:smarttags"
name=3D"place"/>
<!--[if gte mso 9]><xml>
<o:OfficeDocumentSettings>
<o:DoNotRelyOnCSS/>
</o:OfficeDocumentSettings>
</xml><![endif]--><!--[if gte mso 9]><xml>
<w:WordDocument>
<w:SpellingState>Clean</w:SpellingState>
<w:GrammarState>Clean</w:GrammarState>
<w:DocumentKind>DocumentEmail</w:DocumentKind>
<w:EnvelopeVis/>
<w:Compatibility>
<w:UseFELayout/>
</w:Compatibility>
<w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel>
</w:WordDocument>
</xml><![endif]--><!--[if !mso]>
<style>
st1\:*{behavior:url(#default#ieooui) }
</style>
<![endif]-->
<style>
<!--
/* Font Definitions */
@font-face
{font-family:"MS Mincho";
panose-1:2 2 6 9 4 2 5 8 3 4;
mso-font-alt:"\FF2D\FF33 \660E\671D";
mso-font-charset:128;
mso-generic-font-family:modern;
mso-font-pitch:fixed;
mso-font-signature:-1610612033 1757936891 16 0 131231 0;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;
mso-font-charset:0;
mso-generic-font-family:swiss;
mso-font-pitch:variable;
mso-font-signature:553679495 -2147483648 8 0 66047 0;}
@font-face
{font-family:"\@MS Mincho";
panose-1:2 2 6 9 4 2 5 8 3 4;
mso-font-charset:128;
mso-generic-font-family:modern;
mso-font-pitch:fixed;
mso-font-signature:647 134676480 16 0 131231 0;}
@font-face
{font-family:Verdana;
panose-1:2 11 6 4 3 5 4 4 2 4;
mso-font-charset:0;
mso-generic-font-family:swiss;
mso-font-pitch:variable;
mso-font-signature:536871559 0 0 0 415 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{mso-style-parent:"";
margin:0in;
margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:12.0pt;
font-family:"Times New Roman";
mso-fareast-font-family:"MS Mincho";}
a:link, span.MsoHyperlink
{color:blue;
text-decoration:underline;
text-underline:single;}
a:visited, span.MsoHyperlinkFollowed
{color:blue;
text-decoration:underline;
text-underline:single;}
p
{mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
mso-pagination:widow-orphan;
font-size:12.0pt;
font-family:"Times New Roman";
mso-fareast-font-family:"MS Mincho";}
span.EmailStyle17
{mso-style-type:personal-reply;
mso-style-noshow:yes;
mso-ansi-font-size:10.0pt;
mso-bidi-font-size:10.0pt;
font-family:Arial;
mso-ascii-font-family:Arial;
mso-hansi-font-family:Arial;
mso-bidi-font-family:Arial;
color:navy;}
span.SpellE
{mso-style-name:"";
mso-spl-e:yes;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.25in 1.0in 1.25in;
mso-header-margin:.5in;
mso-footer-margin:.5in;
mso-paper-source:0;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 10]>
<style>
/* Style Definitions */=20
table.MsoNormalTable
{mso-style-name:"Table Normal";
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-parent:"";
mso-padding-alt:0in 5.4pt 0in 5.4pt;
mso-para-margin:0in;
mso-para-margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.0pt;
font-family:"Times New Roman";}
</style>
<![endif]-->
</head>
<body lang=3DEN-US link=3Dblue vlink=3Dblue style=3D'tab-interval:.5in'>
<div class=3DSection1>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>Disk staging is good for the right =
reasons
and for the right backups, but everything going to disk for backup is =
like
paying one credit card off with another credit card. <span
style=3D'mso-spacerun:yes'> </span>At some point you need to get =
some or all
of that data on tape for portability.<span =
style=3D'mso-spacerun:yes'>
</span><o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>If what you are trying to do is =
address
reliability, speed and portability, then look at the purposed built =
backup
devices such as Virtual Tape Libraries that support an embedded path to =
tape. <span
style=3D'mso-spacerun:yes'> </span>They will provide the speed of =
disk, RAID
reliability through the convenient presentation of tape and tape =
libraries. <span
style=3D'mso-spacerun:yes'> </span>There are quite a few on the =
market now which
is great for you because you have so many choices…just make sure =
you are
choosing for the right reasons.<o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>My suggestion when considering to =
use “disk”
in your backup infrastructure is to FIRST identify the top three to five
reasons you are looking to address your backup problems with =
“disk”.<span
style=3D'mso-spacerun:yes'> </span><o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>Second ask yourself if tape is an
important factor for your protection strategy?<span
style=3D'mso-spacerun:yes'> </span>If tape is not important to =
your
particular strategy there are many vendor solutions out there that =
imitate tape
but end in disk.<span style=3D'mso-spacerun:yes'> =
</span>Otherwise, the
list narrows considerably as you find those solutions that support an =
embedded
path to tape.<o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>However, if tape is important then =
your
paradigm for backup shifts a little bit to the number of hours needed to =
create
tapes during the “export or eject” window with the <span
class=3DSpellE>VTL’s</span> (that is time to create physical tapes =
via the
embedded path to tape).<span style=3D'mso-spacerun:yes'> </span>So =
doing
the math helps a ton here.<o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>Thirdly and probably most =
importantly,
does it appear on VERITAS’ Support =
matrix?<o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>Create a punch list and ask =
questions...hard
questions of the vendors…and get the right solution for the right =
reasons.<o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>David<o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>BTW:<span =
style=3D'mso-spacerun:yes'>
</span>you can check <span class=3DSpellE>ADIC’s</span> offering =
at <a
href=3D"http://www.adic.com/gopathlightvx";>http://www.adic.com/gopathligh=
tvx</a><o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<div>
<p><b><font size=3D1 color=3Dnavy face=3D"Times New Roman"><span =
style=3D'font-size:
7.5pt;color:navy;font-weight:bold;mso-no-proof:yes'>David A. Chapa =
</span></font></b><font
size=3D1 color=3Dnavy face=3DSymbol><span =
style=3D'font-size:7.5pt;font-family:Symbol;
color:navy;mso-no-proof:yes'>½</span></font><font size=3D1 =
color=3Dnavy><span
style=3D'font-size:7.5pt;color:navy;mso-no-proof:yes'> Technical Advisor =
</span></font><font
size=3D1 color=3Dnavy face=3DSymbol><span =
style=3D'font-size:7.5pt;font-family:Symbol;
color:navy;mso-no-proof:yes'>½</span></font><font size=3D1 =
color=3D"#999999"><span
style=3D'font-size:7.5pt;color:#999999;mso-no-proof:yes'> =
</span></font><b><font
size=3D1 color=3Dred><span =
style=3D'font-size:7.5pt;color:red;font-weight:bold;
mso-no-proof:yes'>ADIC</span></font></b><font size=3D1 =
color=3D"#999999"><span
style=3D'font-size:7.5pt;color:#999999;mso-no-proof:yes'> =
</span></font><font
size=3D1 color=3Dnavy face=3DSymbol><span =
style=3D'font-size:7.5pt;font-family:Symbol;
color:navy;mso-no-proof:yes'>½</span></font><font size=3D1 =
color=3Dnavy><span
style=3D'font-size:7.5pt;color:navy;mso-no-proof:yes'> 720.249.5836 =
</span></font><font
size=3D1 color=3Dnavy face=3DSymbol><span =
style=3D'font-size:7.5pt;font-family:Symbol;
color:navy;mso-no-proof:yes'>½ 720.272.8452 =
</span></font><em><i><font
size=3D1 color=3Dnavy face=3D"Times New Roman"><span =
style=3D'font-size:7.5pt;
color:navy;mso-no-proof:yes'>cell</span></font></i></em><font size=3D1
color=3Dnavy><span =
style=3D'font-size:7.5pt;color:navy;mso-no-proof:yes'> =
</span></font><font
size=3D1 color=3Dnavy face=3DSymbol><span =
style=3D'font-size:7.5pt;font-family:Symbol;
color:navy;mso-no-proof:yes'>½ </span></font><em><i><font =
size=3D1
color=3Dnavy face=3D"Times New Roman"><span =
style=3D'font-size:7.5pt;color:navy;
mso-no-proof:yes'> </span></font></i></em><font color=3Dnavy><span
style=3D'color:navy;mso-no-proof:yes'><a =
href=3D"mailto:david.chapa AT adic DOT com"><font
size=3D1><span =
style=3D'font-size:7.5pt'>david.chapa AT adic DOT
com</span></font></a><o:p></o:=
p></span></font></p>
<p><font size=3D1 color=3Dnavy face=3D"Times New Roman"><span =
style=3D'font-size:7.5pt;
color:navy;mso-no-proof:yes'>HIGH PERFORMANCE, SCALABLE, RELIABLE =
- </span></font><font
color=3Dnavy><span style=3D'color:navy;mso-no-proof:yes'><a
href=3D"http://www.adic.com/gopathlightvx";><font size=3D1><span =
style=3D'font-size:
7.5pt'>http://www.adic.com/gopathlightvx</span></font></a></span></font><=
o:p></o:p></p>
</div>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D2 =
face=3DTahoma><span
style=3D'font-size:10.0pt;font-family:Tahoma'>-----Original =
Message-----<br>
<b><span style=3D'font-weight:bold'>From:</span></b>
veritas-bu-admin AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu] <b><span =
style=3D'font-weight:
bold'>On Behalf Of </span></b>Nash, Ebon<br>
<b><span style=3D'font-weight:bold'>Sent:</span></b> Wednesday, June 09, =
2004
11:26 AM<br>
<b><span style=3D'font-weight:bold'>To:</span></b> 'Johnny Oestergaard'; =
Paul
Esson; veritas-bu AT mailman.eng.auburn DOT edu<br>
<b><span style=3D'font-weight:bold'>Subject:</span></b> RE: [Veritas-bu] =
Disk
Based Backup</span></font></p>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D3 =
face=3D"Times New Roman"><span
style=3D'font-size:12.0pt'><o:p> </o:p></span></font></p>
<div>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D2 =
color=3Dblue face=3DArial><span
style=3D'font-size:10.0pt;font-family:Arial;color:blue'>We moved from =
disk
storage units to disk staging storage units and took a huge performance
hit. The overhead required for disk staging, and apparent =
filesystem
fragmentation due to 100% utilized filesystems, forced us to revert back =
to
disk storage units. If performance is an issue, be wary of disk =
staging
storage units.</span></font><o:p></o:p></p>
</div>
<div>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D3 =
face=3D"Times New Roman"><span
style=3D'font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D3 =
face=3D"Times New Roman"><span
style=3D'font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D2 =
color=3Dblue face=3DArial><span
style=3D'font-size:10.0pt;font-family:Arial;color:blue'>Ebon =
Nash</span></font><o:p></o:p></p>
</div>
<div>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D2 =
color=3Dblue face=3DArial><span
style=3D'font-size:10.0pt;font-family:Arial;color:blue'>Compuware =
Corp.</span></font><o:p></o:p></p>
</div>
<blockquote =
style=3D'margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'>
<p class=3DMsoNormal =
style=3D'mso-margin-top-alt:0in;margin-right:0in;margin-bottom:
12.0pt;margin-left:.5in'><font size=3D2 face=3DTahoma><span =
style=3D'font-size:10.0pt;
font-family:Tahoma'>-----Original Message-----<br>
<b><span style=3D'font-weight:bold'>From:</span></b>
veritas-bu-admin AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu]<b><span =
style=3D'font-weight:
bold'>On Behalf Of </span></b>Johnny Oestergaard<br>
<b><span style=3D'font-weight:bold'>Sent:</span></b> Wednesday, June 09, =
2004
12:41 PM<br>
<b><span style=3D'font-weight:bold'>To:</span></b> Paul Esson;
veritas-bu AT mailman.eng.auburn DOT edu<br>
<b><span style=3D'font-weight:bold'>Subject:</span></b> Re: [Veritas-bu] =
Disk
Based Backup</span></font><o:p></o:p></p>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D3 =
face=3D"Times New Roman"><span
style=3D'font-size:12.0pt'>Regarding speed on disk compared to tape I =
would say
that high-speed tapedrives are much faster then disk except for the time =
it
takes to load and unload the tape. When the tape is at the right =
position tapes
are fast. Our 9940B should be able to take around 70 MB/s if we could =
feen them
that fast. I would like to see a SATA disk system that could take the =
same load
as just 4 of the 9940B drives.<br>
In an installation using diskstaging I see one great thing that I think =
we will
use and that is most of all to stage small backups and slow backups to =
disk and
then let NBU stage them to tape. With a little luck we should be able to =
bring
our multiplexing down and thereby speed tapeduplication up.<br>
<br>
What makes tapeduplication slow is most of all on duplexed tapes. We run =
some
tests on duplication speed on backups that where not duplexed some years =
ago,
and as I remember it we did this at almost the max speed of the drives =
(We did
3 tests on 9940A drives)<br>
<br>
I would use vault to make my off-site copies<br>
<br>
/johnny<br>
<br>
At 17:24 09-06-2004 +0100, Paul Esson wrote:<br =
style=3D'mso-special-character:
line-break'>
<![if !supportLineBreakNewLine]><br =
style=3D'mso-special-character:line-break'>
<![endif]><o:p></o:p></span></font></p>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D2 =
face=3DVerdana><span
style=3D'font-size:10.0pt;font-family:Verdana'>Folks,</span></font><br>
<br>
<font size=3D2 face=3DVerdana><span =
style=3D'font-size:10.0pt;font-family:Verdana'>I
am currently deliberating over disk based backup options and would =
welcome
comments from those with first hand experience. </span></font><br>
<br>
<font size=3D2 face=3DVerdana><span =
style=3D'font-size:10.0pt;font-family:Verdana'>Specifically,
I am trying to way up the pros and cons of using a Virtual Tape Library =
versus
sharing storage out to media servers from say a SATA disk array. =
The
latter looks attractive particularly since the introduction in v5.0 of =
Disk
Staging Storage Units (DSSUs). Is anyone using DSSUs =
currently?
With VTL there seems to be the cost issue of licensing drives as in a =
regular
library.</span></font><br>
<br>
<font size=3D2 face=3DVerdana><span =
style=3D'font-size:10.0pt;font-family:Verdana'>What
I would like to do is write all backups initially to disk but then stage =
the
full backups to tape. I had hoped to create two tape copies one to =
remain
onsite (in a tape library) and the other to go offsite. However, I =
am
somewhat confused as to the NetBackup functionality required to achieve
this? If I use the DSSU the data appears to be migrated to tape as =
part
of the policy anyway, but how would I achieve my twin copies on tape, =
ideally
with different retention levels? Do I actually require to use =
inline copy
or even Vault (duplication) to achieve my end? The concern I have =
with
inline copy is that the quicker write to disk will be negated by having =
to
write to tape at the same time and before the job completes. As =
for Vault
I don't know the product at all but believe it is licensed by drive (How =
does
this work if your source is a disk storage unit?) and that could prove
costly. I have also read on this list adverse comments about =
duplication
speeds, although I would be writing from disk to tape.</span></font><br>
<br>
<font size=3D2 face=3DVerdana><span =
style=3D'font-size:10.0pt;font-family:Verdana'>All
comments on any of these items very welcome.</span></font><br>
<br>
<font size=3D2 face=3DVerdana><span =
style=3D'font-size:10.0pt;font-family:Verdana'>Regards,</span></font><br>=
<br>
Paul Esson<br>
Senior Support Engineer<br>
Redstor Limited<br>
<br>
Direct: +44 (0) 1224 =
595381<br>
<st1:City><st1:place>Mobile</st1:place></st1:City>: &nbs=
p;
+44 (0) 7766 906514<br>
E-Mail: =
paul.esson AT redstor DOT com<br>
Web: =
<a
href=3D"http://www.redstor.com/"; =
eudora=3Dautourl>www.redstor.com</a><br>
<br>
REDSTOR LIMITED<br>
Torridon House<br>
73-75 Regent Quay<br>
<st1:City><st1:place>Aberdeen</st1:place></st1:City><br>
<st1:country-region><st1:place>UK</st1:place></st1:country-region><br>
AB11 5AR<br>
<br>
Disclaimer:<br>
The information included in this e-mail is of a confidential nature and =
is
intended only for the addressee. If you are not the intended =
addressee,
any disclosure, copying or distribution by you is prohibited and may be
unlawful. Disclosure to any party other than the addressee, =
whether
inadvertent or otherwise is not intended to waive privilege or
confidentiality.<?xml:namespace prefix =3D o ns =3D =
"urn:schemas-microsoft-com:office:office"
/><br>
<o:p></o:p></p>
</blockquote>
</div>
</body>
</html>
<BR>
<BR>
<BR>
<P><B><FONT SIZE=3D2 FACE=3D"Arial">The contents of this e-mail are =
intended for the named addressee only. It contains information that may =
be confidential. Unless you are the named addressee or an authorized =
designee, you may not copy or use it, or disclose it to anyone else. If =
you received it in error please notify us immediately and then destroy =
it.</FONT></B> </P>
<BR>=00
------_=_NextPart_001_01C45241.C0EF5F44--
|
