What Is Data Deduplication? (Encore)

Yeah.

the other thing people don't realize is five gigahertz,

like degrades like no tomorrow

me why five gertz is better again.

It's faster because it can handle more bandwidth, and also the channel

is wider, so you can have more things talking at the same time.

It's just as your frequency goes up, the distance goes

down for the same power levels,

So is this like DC versus ac?

not quite DC versus ac.

It's more about.

You need to pump as many things as possible into, because high frequency,

it's more per cycle, than 2.4, which is less airtime, if you will.

And so every sort of peak, you can send more out with the five gigahertz

because you're doing it more often.

And so it works a lot better.

It's just the distance isn't as great.

Now, I will tell people, so this is one of my, I'm gonna

get up on my soapbox now, right?

One of my rare soapbox events and tell people, a lot of times people

think they need more wifi access points in their house to get coverage.

Mm-hmm.

to those people, I will say, plan out your network carefully.

Put your devices where they matter.

Mm-hmm.

And also don't put too many devices and don't crank up the power all the way

to high, because I know Curtis, you and I were talking about this when you're

looking at mesh, and it was like, imagine that your router can overpower your

phone, your laptop, your iPad, so it's screaming at the top of its lungs and your

phone can barely even scream back at it.

And so that's actually worse for your network and for airtime than

actually balancing out power.

I just don't know if, the stuff you're talking about, like is.

is that even, is that configuration option even on consumer class routers?

you'll have the low, medium, high power levels,

but it takes time to fine tune and tweet these, right?

You have to walk around with a wifi analyzer on your phone, right?

So Apple with their, iPhones, right?

They ship, what is it?

Airport utility, which has a wifi scan.

Option, which will show you all the wifi networks and the signal

strength, and you basically have to walk around your house with that and

be like, okay, where is it strong?

Where is it weak?

figure out the placement.

That's the ideal way, because what you want is you want coverage in the right

places, because what is in a lot of high density housing areas, or even homes next

to each other is most people end up with crummy wifi because their power is turned

up so high, it bleeds into everyone else's area such that everyone has a crappy time.

because then you get interference and then everyone slows down and then it

Yeah.

I got a lot of wifi.

I got a lot of networks.

yeah,

and for the last bit of my soapbox is please do not use 40 megahertz channel

widths on your 2.4 gigahertz channels.

You do not need to use 40 megahertz and ruin everyone else's connectivity.

Please only use 20 megahertz bands for 2.4 gigahertz.

I'll see what I can do

but I have this new, and again, I am not a wireless, I feel like a

wireless nbe, but I have this new fancy right where it automatically selects

Mm-hmm.

the right.

that's

access.

Point to go.

Yeah.

Yeah.

And actually

also

the.

versus

Yep.

So actually all of this is part of the wifi standard, so the figuring

out which access point, that's part of the 8 0 2 11 R standard.

And I think that the band steering is also part of the standard as well.

Yeah.

a lot of folks are implementing now.

Some devices don't do well with band steering.

It basically looks at sort of the difference between the five gigahertz

and the 2.4 gigahertz and says, okay, which one should I pick?

And most devices, if it's seven decibels difference or more, then

it'll pick, the higher the faster speed.

And so that's how it tricks your devices into picking the right band.

Interesting.

Yeah, it's cool.

It's magic though.

that I finally have mesh that covers the two.

Cuz my problem is that I have things in the garage, things embedded

inside walls in the garage that need wifi, not just inside walls.

, I have a device that's inside a wall, inside an electrical

cabinet, inside a wall.

have a sense, app or

Yep.

a device, and that's deep inside my electrical, my circuit breaker

No.

and this reached to it.

No problem.

It didn't, it had two bars.

So clearly, and the thing is, it's only, it's 20 feet from.

yep.

But it's, a couple of drywall walls and

And,

by fours and some metal.

but it worked.

That's the important part is that it worked.

yeah, so I th I think I might be in, I think I might be in wifi heaven

Woohoo.

and you too can be there for the low price of $350 That's a

two, that's a two node system.

it's supposed yeah, but I'm pretty happy.

But, that's not what we're talking about today.

really.

We can talk about wifi all day if you want.

yeah.

you could talk about wifi all day.

I feel really stupid when you're talking about wifi, because

I'm like, this is not my Wick.

That's a cool word, by the way, Bailey Wick.

So I thought we'd talk about backups instead because that's my world.

And I feel comfortable knowing them.

Most people don't know crap about this space, because they, they get

the job as a junior person and then next thing you know, they become a

real sys admin or a network admin or a, or a security admin or a dba.

Yeah, except our listeners who are all awesome and probably experts in the

backup field and know all about this.

certainly Daniel.

Hi Daniel.

Hi Daniel.

The backup anorak.

I wonder, he's never, he better still be listening to the show since we

call out to him every once in a while.

Him and Stuart, although Stuart's retired.

I don't think Stuart's listening to our show.

I only tell 'em when we talk about 'em.

But, so we're continuing in our backup to basic series.

It's been a couple of weeks, as the kids say it's been a minute,

since a, I remember the first time I heard that thing, I was like,

what are you talking a minute?

Anyway, . But yeah, it's been a minute since we've done an episode of our

Backup to Basic series, I am looking down at the book and of course, for

those of you that don't know, basically we're doing a podcast version of

my book, modern Data Protection.

Make sure it gets in camera here from O'Reilly.

you can purchase the, the print version from, your favorite seller.

, perhaps it's one based in the Amazon, perhaps not, and, but if you would like

an ebook version of it, you can get your own by going to druva.com/ebook.

That's d r uva.com/ebook.

will, of course, ask for your contact information then email the crap out

of you until you tell 'em to stop.

But, that is the price that you pay.

let's talk

about, oh

And

And while we're at

I'll throw out the disclaimer, that this is an independent podcast I work

for Druva, Prasanna works for Zoom and,

The, but the opinions that you hear are ours.

and.

Et cetera.

Please rate us, by going to your, most of you're on iTunes.

Just scroll down to the bottom there, give us five or six stars and a comment.

We love comments.

And, if you'd like to join the conversation, just contact me, w Curtis

Preston gmail or WC Preston on Twitter.

What about LinkedIn?

But n yeah, LinkedIn.

it's linkedin.com/what is it?

Slash in

Yep.

Mr. Beck.

and by the way, my Twitter account already has multifactor authentication, configured

not using sms, which as should you, especially now that they're disabling,

that so weird the way they did that.

What's funny is I support the desysion.

That's just way

the way

it came out.

Yeah.

Oh, Elon.

Okay.

So in our backup to basic series, we're continuing on, and today we are talking

about using disk and deduplication.

I, I, couple weeks ago, I hit 30 years in the backup industry, and

I got interviewed by Chris Mellor

the register and blocks and files.

Yeah.

It's in his, for his block and file.

blog

one of the questions was what I thought was the most, important development

in the backup industry since I joined.

And to me, hands down, not even, not, there's not even a close second, and

that is the invention of deduplication

Yep.

and because.

I can't think of another technology in the backup space that has changed backup

architecture more than deduplication, and I can think of many other things

that we do that are only possible because deduplication is underneath them,

Oh yeah, definitely.

Yeah.

I don't think we would be able to get, especially with the data growth

and the size of these applications.

Is data growing?

Is

No, not at all.

I don't think it would be possible to do, like I know Curtis, you've talked

about previous, like in your early days, about trying to do a backup.

I being like, oh my God, how am I gonna do this full backup in a weekend?

Yeah.

And just with the fact, and I know we'll go and talk about more about

deduplication, but yeah, just being able to now do that in a cost

effective way, using new ways of actually doing the backups as well,

which is enabled with deduplication.

Yeah.

So it's like disk.

You could argue that disk using disk and backups the bigger, advancement.

But first off, not really an advancement.

It's just instead of tape, we're gonna use disc,

which was there to start with anyway.

It was just the cost was so high, and especially given the type of workload

with deduplication where, or with backups where you're doing periodic

fulls or other things like that, and keeping them for long periods of time.

Are you going to spend what, 40 x or 30 x on storage for your backup

system versus your production?

That's a hard sell.

just, yeah, cuz that's a problem.

So one of the, one of the things, that I remember from back in the

day, like I, I don't remember really thinking about this lately, but back

in the day, I would say that for every gigabyte of primary storage, you

had 20 gigabytes of backup storage.

Mm-hmm.

And so if you're gonna do that with disk, even, even once, many years ago.

Wow.

At this point, it's 20 years ago, but even once they came

out with this idea of, SATA disk

Yep.

of

nearline

storage.

that, that helped bring the cost down significantly.

But not as much as deduplication.

Yeah.

Because even with those price differences, right?

Maybe it was half the price or a third of the price, but once you add in that

20 x that you talked about, Curtis,

Yeah.

that adds up.

And it's not only just the storage cost, it's also you have

to account for the power, the cooling, the floor space, right?

All the things that go into that system.

Yeah.

Yeah.

it's funny, just a, an afterthought that, that.

Post that, that Chris Mellor did about the 30 years.

The one group that jumped on the article and just started retweeting

all kinds of parts of, or pieces of the article was the tape group , because

I said really good things about tape.

and the thing is that, I, I believe in all of those things, but.

all of the advancements that I've seen in backup in the last 20 plus

years has been disk and deduplication.

so let's talk about, so what, so not everybody really

understands what deduplication is.

Some people used to describe it like, it's like compression,

the way I remember it's like macro compression.

it's like compression over

Yeah.

What do you think of that?

I don't quite like that,

having,

some old blog posts that I might have said that phrase, but go ahead.

so in my mind, deduplication is.

Finding two identical segments and tossing one away, keeping only one copy, but still

keeping a reference to that so you can, so you still know you have two virtual

copies, but one physical copy, right?

At a high level, that's what I, and now

you?

what is compression is taking an object, a singular object, and

squeezing it into a smaller space.

But how do you understand how compression works?

Cuz I Sure as hell don't

yeah, so typically like you would run it through different types of algorithms

like LZ compression and all the rest in order to look for patterns and

throw away bits and compress it down.

Now, the difference I would say between duping compression

because they do sound the same,

Yeah.

right?

I would say one of the differences is with deduplication.

It's more like a file system level compression, if you want to

think of it that way, because it's not just I'm taking this block.

Yeah.

It's not just I'm taking this and I'm squeezing it down such

that it could be, I just need to look at this and figure it out.

It's a lot more complex than that.

It is definitely a lot more complex than compression.

I've just, I've just honestly never dug into the code of how

traditional compression works.

So the idea is that I'm looking for duplicate segments of data across many

places, both from different sources as well as different time periods, right?

Yep.

the, this chunk of data that's coming in right now and tonight's backup.

I'm comparing it literally with every chunk of data that I've ever received

It.

else.

. I would say that's an ideal system, but not everyone builds

their deduplication that way.

where

it's

in.

yeah, go ahead.

Yeah.

So it all goes down to what is your deduplication domain is another term

that some people talk about, right?

Which is it limited to a system?

Is it limited to a cluster which might be formed to multiple

systems, or is it limited to a single backup stream coming in?

Right.

So

there.

that the question is what is your data domain?

Yeah.

D Domain.

So let's back up.

So a, as I understand it, right, so basically we're taking the data

that's, that's coming in or that's going to come in, we're slicing

it up into, I like the term chunk.

, right?

We run those chunks through a cryptographic hashing algorithm.

one, Shaw 2 56, whatever it, whatever you're using.

On the other side of that, we get a alpha numeric value, in the case of SH one,

it's 160 bit alpha alphanumeric value.

so basically you, depending on the algorithm you use, you get a, you get an

alpha numeric value at the end, and the size of that val, of that value is going

to be based on which algorithm you use.

In the case of SHA-1, 160 bits, right?

You can then take the 160 bits.

You can't reverse engineer it.

You can't take the 160 bits and turn it into the chunk, but you can use that

value to uniquely identify that chunk.

Yep.

have another chunk of data, regardless of where it came from, If it's 160

bit value, again, that's SHA-1 and

Yep.

are different.

If it's fingerprint is the same, you can say that this chunk is identical to that

Yep.

that had the same fingerprint, and you can then discard other chunk, right?

Yeah,

you can discard the actual data, but you should still keep track

of it somewhere in a file system, just because you need, still need

Yeah.

You're gonna keep track.

Oh, we found another one of these,

Yeah.

And so usually that lookup is in a deduplication index

is what they called them.

Usually a dedupe index, Right.

which keeps a list of, Hey, here are all the fingerprints that I have.

As we, we were alluding to before, one of the things that determines

sort of your effectiveness of dedupe is the dedupe domain, right?

So I've seen it file system level, meaning it only looks for

duplicate data within each volume.

I've seen it host level, I've seen it backup level, meaning

literally backup configuration wise.

Yeah.

So if I have a Windows server and I'm backing up the host and I'm

backing up SQL Server, I only look for duplicates within SQL Server

backups right against each other.

then we have, if we're backing up several systems to a box, right?

Maybe

Mm-hmm.

the dedupe domain is only within that box.

It's only looking for.

Duplicates between all of that.

And then there's what I would call truly global dedupe, which is we're

looking for duplicates from everything coming in, from multiple sources.

there is Point of decreasing marginal returns, right?

You can argue, and certainly if you're a company that only does d dedupe within,

like earlier I was, we only looked for dupes within SQL server backups.

yep.

You could make an argument that, there's not a lot of duplicate data

between SQL Server and Windows,

Yep.

so

And so you keep 'em separate.

two,

not gonna be a lot of duplicate data there, and there's not

gonna be a lot of duplicate.

between the SQL Server database on this host and the SQL

Server database on that host.

Yeah,

that's another argument that some

make

but I think a lot of that was because of architectural limitations of the

products themselves rather than, that is really what you wanted to do.

Because

that's more of a management issue.

they didn't, it was like, if we're gonna do it, if we're gonna do it

that way, it's gonna be much harder.

Yeah.

to design a product to do it that way.

And we don't think, we don't think that there's going to

be that much more benefit,

But on the other hand, if you look at things like VMware, right?

If I have a bunch of VMs, there's a good cha, and they all came

from a single golden image, right?

There's a good chance that as you're backing it up, 80, 90% of that stuff

is all gonna be deduplicated, right?

Absolutely.

Yeah.

There's also a lot of duplicate data even within a large filer, right?

There's gonna

Yeah.

of duplicate data there, right?

So if you're only doing it volume to volume or backup configuration

to backup configuration, you, there's a lot of duplicate data

that I think you would miss.

Yeah.

I know you talked about the domains, but I think another thing to also

mention is, Some products do different types of chunking, if you will.

Some do it at the file level, others do it at a smaller level, right?

And some do fixed segment where each one is a fixed length.

Others do variable segments where they try to figure out what is optimal,

because depending on how you're doing your fingerprinting, you want to find

the most number of matches, right?

So you can save on storage.

another thing that also comes up.

I would argue that file level dedupe isn't really dedupe,

it's more a single instance.

that's like single instance storage of a file,

Okay.

it's, yeah.

But I'm always thinking subfile, when

Yep.

what I think of actual dedupe . There is a much, like a very big, other

way that we divide up the dedupe industry, that is source versus target.

Yep.

the, the first dedupe product I ever saw,

Hydro store.

was, no, was not,

No.

not the first, no, the first one I saw the product at the time was called Undo.

Have we talked

Interesting.

Undo with two Os.

It was really funny that the name of a dedupe vendor.

Had duplicate data in their company name.

It was undoo with two os.

You know this product, you just don't know that's what it used to be called.

What is it?

What

is the product?

I'll give you a hint.

It.

The name comes from the fact that it would be a C of availability.

I'm gonna, I'm gonna put the Jeopardy theme in here.

What would it see of availability?

That's what the name, that's where the name for the company comes

from, or if I want to put it in the right order, an availability c.

I don't know what this is.

Avamar

oh, that makes sense.

Yeah.

that's where the name Avamar came from.

So the first

I should know that

you shouldn't know

I having being, part of my former employer.

Yes.

Yeah.

I, I have a bit of an inside track because that they're, They

were right up the road from me,

Yep.

were up there.

They were up in Irvine.

and that was, the first dedupe product.

They were a source dedupe . So what's the difference between source

dedupe and target dedupe Prasanna?

So the biggest one is, so let's first talk about target tup, right?

So Target Tup is data comes into the system and then a deduplication

algorithm runs tosses away data.

It can support any type of client as long as it supports

whatever the protocol it has.

So it's NFS or smb, right?

Whatever can write to it, the data gets deduped.

hang on.

Before you go on to that.

I don't disagree with what you said.

I just, I think there could be a little bit more clarification.

It's a box I send whatever I want to.

Yep.

Typically it, the thing about Target Dedup was that, that it was, you didn't

have to do a lot of re-engineering of

seamless.

Yeah,

Right.

a VTL system, right?

That came.

plug in a box.

Yeah.

And you would send you, and basically you stopped using tape and you

sent your backups to this box.

Maybe the box might even be pretending to be a tape library,

the virtual tape library.

and then it did all the dedupe magic over there.

Which was great because you can just plug in your box and go.

Yeah.

the other side is called source side dedupe, instead of sending all the data

and tossing it away, why don't we do something smart and actually figure out

the duplicates on the client itself, on the source right, dedupe on the

source, and only send the unique data.

And this has the advantage.

Actually not sending the data over the wire, which is actually

a huge benefit that people don't understand always, right?

Is not sending the data can actually make it a lot faster, even though

you think, oh, I'm now putting additional load on my server itself.

But it ends up being better than trying to send all the data and just tossing

it away like target-side dedupe does.

I would say it theoretically should be better

right?

Because

I.

I'm just saying I've seen some crappy source

Yeah.

right?

Okay.

Sorry.

I've seen some, I've seen some good ones, or the ones that I've

interacted with have been good.

And so I've seen the performance numbers around

turning it

I do think it, it makes more sense to me.

It always made more sense to me.

The only reason why we had Target dedupe was because to do source dedupe , you

have to redesign the backup product.

, Yeah.

It took a long time to get, basically you have to stop using net backup networker

Yeah.

whatever it was back in the day, and you had to replace it.

Like in this case with Avamar, Avamar

Yep.

do-do product.

You had to do what we call a four clipped upgrade.

You had to throw out the baby with

Yep.

whatever phrase, whatever.

analogy you want to use there.

That was the main problem as I saw it with source dedup.

is that you had to change your backup product to get it,

Well, and that was in the beginning, right?

At the very early

You.

You, yeah.

Now you just had to upgrade your backup product,

Yeah.

Because many of modern backup technologies now support source dedupe , although even

all.

backup technologies don't, I don't

Yeah.

I dunno if that came out in English, so some I, there was

some double negatives in there.

Some very new backup technologies.

Don't do source dedupe

. which seems bunkers.

which does seem bonkers.

and, I'm talking about the likes of Rubric and Cohesity, right?

These are new, these are, next gen backup products that were designed

in the last, than the last 10 years.

And it's based on an appliance model.

and they do all the dedupe inside that box, is my understanding, right?

And I just wanna challenge that, Curtis, because I thought in some cases,

Mm-hmm.

They do source side deduplication, but I think because they've tried to

be open and act as a target device, in those cases, you can't, you

don't really have another option.

Yeah, I don't, again, I'm not,

I, but I don't know

work at Druva, not at Rubrik,

or Cohesity.

But it is my understanding that they do target side dedup, which is,

and one of the challenges of target side dedup is need an appliance.

at each location.

Now I know that they can do virtual appliances, right?

So they have a VM level appliance.

but you need a box or something pretending to be a box at each location, because

if you're not eliminating the duplicates before you send it to the box, then you

need something that's on-prem, right?

Because you definitely don't wanna send that all over the Wan

no, that's the, to me, that's the biggest advantage of a source dedupe

system is that it's ultimately scalable,

Yep.

That you, that assuming it doesn't slow things down, all these things,

assuming that the product actually works, that you, you could back up a laptop.

, right?

You can back up a mobile phone and the duplicate data will be eliminated

before it's sent over the wan, which is what you need to do if you're

backing up something over the internet.

so the downside that some, again, you talked about it already, is that it does

put additional compute on the client.

The argument is that it's offset by the,

the savings of the network bandwidth.

There is also one more downside,

okay.

which is that.

Not all applications can do source side deduplication.

So if you do have an application which only supports writing to like an NFS Mount

point or an SMB Mount point, or something that doesn't allow the integration of

these source side duplication logic, then you are going to need to be

able to support target side dedupe.

do.

Yep.

agreed.

and an example of that would be like, Oracle, right?

Yep.

Right.

merge.

yeah.

I would think that you should be able, I don't know, we

No, you can't.

You can't.

You can't.

You can't take the Oracle stream and slice it and dice it.

I don't know.

Did you what?

Sorry?

You could, there are companies out there which give, which provide

a virtual file system interface

that lives

on the client.

it.

You fake

Yeah.

Yeah.

Yep.

All right.

And then I've got something called hybrid dedupe and this was

invented by your former employer.

I don't even know what a hybrid dedupe is.

it's Target Dedoo pretending to be Source cdu.

Target D. Oh, see, here's my, okay, so here's my problem is I think Boost

Uhhuh.

is source.

I deduplication, I don't know if I would call it hybrid, because it is

very similar to what Avamar DI did.

, right?

It's moving the deduplication logic to the client

Mm-hmm.

such that you could do all of the computation.

The same thing that we have talked about with source I deduplication,

I'll tell you why I put it in a different category.

To me, hybrid dedupe is redoing the backup software.

I'm sorry, source dedupe, source iDation.

It's done at

Okay.

software level,

Okay, then.

I

with hybrid dedupe . I'm still dumb sending everything to this source dedupe

thing that's gonna redo it, right?

doesn't matter in the end, you get

the benefits.

benefits, right?

that's what,

Okay.

So with hybrid, yeah.

You get the benefits of source without having to upgrade and, or sorry,

throw away your backup software.

so I, we spent most of this time talking about dedupe there are

a bunch of different ways to use disk in your backup system.

Some of which don't really require dedup, right?

We used to do what we call disk cashing, where you just had enough

disk for last night's backup.

You would back up to disk and then you would copy that to tape, and then

you would hand that to a man in a van.

we got a bunch of different things.

I got D to T D to D to C, and D to C. Did I do all that?

So dis to tape disc, to disc to disk, direct cloud and

dis to disc to cloud, right?

So these are all that people use disk in current backup systems.

to me, D to C or disto disc to cloud is really dis to disc.

To disc is just the cloud is or the

Yeah.

Is a desk.

Yeah.

right?

And I will say that dedupe , by the way, I will say that without d. The

whole thing of using the cloud, the way we use the cloud just wouldn't work.

you can't send full backups to the cloud.

you could

you could, but it would be well, and yeah, with unlimited bandwidth

it would just be expensive.

Just going back to the conversation we had earlier about the wan, right?

You don't wanna send full copies out to over the wan.

because that gets expensive and very slow.

the other one I was going to comment on was, oh, I know we've been

talking about disk, but I think it's also important to acknowledge that

now it's no longer spinning disk.

It could also be flash.

We've seen

yeah,

but that's a

I know.

thing

I, know, but I'm just saying that when it comes to deduplication and backup

ST or protection storage, right?

This, it could be flash, it could be disk, it could be object storage, right?

So I think it's important to differentiate that, like what we're

talking about with deduplication, when we mentioned disk, right?

The media layer itself.

Yeah, the media layer.

Yes.

The media layer is not tape.

Hang on one second.

I need to, didn't realize I had a, Meeting

Meaning a.

Yeah.

Four.

four 15, which is an odd, all right.

it's a pre-meeting with a podcast thing.

It's, anyway, yeah, okay,

Just, just

of flash

flash and backup,

I'm just saying that people will bring it up.

So I just wanna clarify that when we talk about disc, we're

just talking about not tape.

The only place.

Yeah.

Correct.

The only place where I think maybe Flash has a place in the backup

system is, and the folks over at Pierre and Neil, mad at me now.

But, the only place that I, where I think Flash has a place in the backup

system is with like live recovery.

If you're gonna

Yep.

if you're gonna do instant recovery and you're actually gonna run VMs

off of your backups, that better be some really nice performing disk.

Yeah.

the thing is, it doesn't need to be your whole system.

It just needs to

Yeah.

A part of, and it needs to, you don't need your entire system to be flash,

Yeah.

You just

need

yeah,

enough to be able to support that use case.

I just think that where Flash does really, Is in random access, right?

Backup isn't a random access application.

Backup is a streaming application.

Even if what we're talking about large dedupe chunks.

I don't

yeah,

I,

say, let's just say the jury is out for me.

I am in Missouri.

Missouri.

is that the show me state?

That's the show me state.

yeah.

So I'll tell you what, I'll tell you what.

If there's anybody that's listening to this that just got pissed off,

what's his

name?

I'll come back

on.

I welcome you to, come on and tell me why I'm wrong.

I just,

I,

know who will come back on, you

know who,

will come back on,

what's his name?

Bass Data guy.

oh.

Oh, are they flash

Yeah,

mark?

No, sorry, Howard.

Yeah.

Fastest.

Pure flash.

Yeah.

Yeah.

all All right.

yeah, Howard, you wanna tell me why I'm wrong?

I'm more than happy to have you back.

We can duke it out.

We can duke it.

wouldn't be the first time.

Howard and I have disagreed on something.

I don't know.

it's just there are so many area, there are so many other places where I would

wanna spend money in the backup system.

Yep.

but,

comes down to what the cost is.

If you could get flash down to a low enough point,

which

sense.

of vast data,

Yeah.

architecture allows using flash in a, a significant way,

that's why I brought

close to cost.

Okay.

All

Yeah.

Okay.

All right.

All right.

right.

and then I got this whole other thing.

I'm not gonna go into that other thing.

but yeah, so d makes disk and cloud-based both physiologically feasible as

well as economically feasible.

is.

Is there something that a person shopping for a dedupe system should be asking?

Well,

the important things that they should be asking in order to determine

yeah,

does it.

great question.

I think the question would be things about what's the restored performance?

Because in the end, that's the only thing that matters.

I remember.

A product.

Now, this product is still on the market, but I believe they

have addressed this issue.

remember a dedupe product.

It was a Target dedupe product that had, I remember that had 400 megabytes

a second throughput in an appliance.

And like 10 megabits out

it was 40, megabytes out.

It had a 90%, what we call dedupe tax.

Yep.

the, because the problem with dedupe, depending on how you

store it, is that you've got everything you need all over the

All over the place.

Yep.

And so this was just a really bad design.

And I believe that they addressed it and, because that product

is still on the market today.

But that version, one of that product was ble.

so yeah, it's about restored performance, right?

So one thing, oh, I'm.

dedupe ratio is crap.

Don't look at dedupe ratio.

dedupe ratio is a made up number.

I will, I'll go back to, I'll pick on Avamar.

Avamar.

Back in the day, they used to

Oh,

had a 400 to one DEDUP ratio.

Do you remember this?

Because

I remember.

every backup as a full backup.

They're like, the way we store backups, which is the same way Druva stores

backups, the way we store backups.

It's even though they're incremental, it's like they're a full.

, right?

Because they behave a full during a restore.

And so they considered every backup a full.

And so they said, then therefore the dedup ratio is 400 to one.

that was always complete nonsense.

the other would be, I remember, again, I'm gonna pick on people equally.

I remember sales reps of a certain large target.

company that where you might've worked, where they would tell customers to go

and do full backups more frequently because it made their dedup ratio better.

, which is just, again, nonsense.

What matters, in my opinion, what matters is how big is full backup versus

how big are all the backups, right?

if I have.

If I, let me explain what I'm saying.

If I have a hundred terabytes, if one full backup of my environment is a hundred

terabytes and then after three months how big is, or whatever number you want.

but it's just three months seems like a nice, long,

what

POC thing,

Yep.

after a hundred, after, three months, how.

How much stuff is stored over there?

That's what I'm saying.

Don't dedupe ratios is nonsense that didn't come out in English.

dedupe ratios are nonsense, but if I can fit a hundred terabytes right, if I have

a hundred terabyte environment and then a series of incremental backups, and then

over there, my question is how big is.

How much data did

Space.

Yep.

let's say it's 200 terabytes after 90 days.

And then compare that with another product who writes a hundred terabytes?

You backed up the same data, but you used half as much storage on the back end.

. Yep.

I'm saying.

the problem is, and the other reason, and again, I'm a little extra

sensitive to this cuz I work for Druva.

People ask us what's our dedupe ratio?

We're like, the thing is we're like the opposite of Avamar.

we're actually similar to Avamar in that we're source I dedupe,

but we don't use that funny math.

So we could say

Yeah.

but that's nonsense.

So you know, we say, we.

because we also do incremental forever backups.

the problem.

but I know that on average, if we have a hundred terabyte customer, we store,

roughly a year's worth of backups in less than a hundred terabytes of disk.

Yeah.

Right.

And I think it's important there to also account for that increment, like

how I look at these like numbers.

I totally get what you said, Curtis, like you should just do an apples.

But

Yeah.

don't have that ability, you should also look to say, okay,

I have a hundred terabyte full.

And then say, my daily change rate is 2%.

right?

So if I do 2% for a month, right?

That's, what is that two 60?

60 more terabytes, right?

So it should be 160 terabytes worth of data that I sent over, right?

For 160 terabytes worth of data, how much should I actually store?

Yeah.

you similar things to what you're saying, right?

But

The,

because what you're saying is if you had the two products, then

you could do a direct comparison.

But I'm saying if you don't have the two products, then

here's another way you could

I, I would argue that there's no way to compare them if you

don't have two pro, if you're

Yeah.

if you're not doing a true comparison.

A

it's just that d math is funny, right?

So different products charge differently, right?

You look

Yeah.

like when you look at Metallic, which competes with Druva, they have a frontend

price and we have a backend price.

Yeah.

They actually have the front end price, and then you also need

to pay for the backend storage.

So you're paying, so how do you compare that?

it's just, it's difficult

hard.

Yeah.

it's hard.

but all I'm saying is dedup ratio is crap and

Yep,

anything.

but what does matter is how much data are you storing on that backend because

you will be paying for that one way

Yep.

All right.

I don't know if we made this, if we, if this is clear as mud or what, but,

I hope that was helpful and, maybe we ticked off Howard and Howard's

gonna come on next week's episode.

. I dunno.

All

join us,

Howard,

thanks for, thanks for helping me with my network as well,

anytime, Curtis.

Just remember I am not tech support.

Yeah.

Yeah.

All right.

and thanks to the listeners and remember to subscribe.

The Backup Wrap Up is written, recorded, and produced by me, W. Curtis Preston.

If you need backup or DR consulting, content generation, or expert witness

work, check out backupcentral.com.

You can also find links for my O'Reilly books on the same website.

Remember, this is an independent podcast, and any opinions that

you hear are those of the speaker and not necessarily an employer.

Thanks for listening