Looking for SAS/SATA RAID Controller That Supports JBOD
I'm looking for a SAS/SATA RAID controller (preferably with a decent battery
backed cache) that has a mode to support JBOD for mounting individual
physical SATA drives. I am NOT looking for RAID 0 support on a single
drive. I need to be able to freely exchange the drive between different
JBOD SATA controllers on different computers. The application is data
exchange between computers where a network is not easily available (without
time consuming firewall configuration). It would be highly desirable to
plop in a hotswap drive, configure it as JBOD, write data to it, and then
take it off to the destination system where it could be freely read by any
SATA JBOD controller. We would also use this for the occasional backup,
where the restore might get done much later on a different host
configuration.
Re: Looking for SAS/SATA RAID Controller That Supports JBOD
"Will" <westes-usc@noemail.nospam> wrote in message news:fYOdnbxdC-8YdTXbnZ2dnUVZ_u2mnZ2d@giganews.com
> I'm looking for a SAS/SATA RAID controller (preferably with a decent battery
> backed cache)
> that has a mode to support JBOD for mounting individual physical SATA drives.
Are there any that don't?
> I am NOT looking for RAID 0 support on a single drive.
Why not? Is there a problem with that? What's the difference.
> I need to be able to freely exchange the drive between different
> JBOD SATA controllers on different computers. The application is data
> exchange between computers where a network is not easily available (without
> time consuming firewall configuration). It would be highly desirable to
> plop in a hotswap drive, configure it as JBOD, write data to it, and then
> take it off to the destination system where it could be freely read by any
> SATA JBOD controller.
What the hell is a "SATA JBOD controller".
There is JBOD as in "a JBOD cabinet" and there is JBOD as in "a JBOD array", which is a RAID mode.
> We would also use this for the occasional backup,
> where the restore might get done much later on a different host
> configuration.
Re: Looking for SAS/SATA RAID Controller That Supports JBOD
"Folkert Rienstra" <see_reply-to@myweb.nl> wrote in message
news:46a92b0e$0$97248$892e7fe2@authen.yellow.readf reenews.net...
> "Will" <westes-usc@noemail.nospam> wrote in message
> news:fYOdnbxdC-8YdTXbnZ2dnUVZ_u2mnZ2d@giganews.com
>> I'm looking for a SAS/SATA RAID controller (preferably with a decent
>> battery
>> backed cache)
>
>> that has a mode to support JBOD for mounting individual physical SATA
>> drives.
>
> Are there any that don't?
95% of them yes.
>> I am NOT looking for RAID 0 support on a single drive.
>
> Why not? Is there a problem with that? What's the difference.
Single drive RAID 0 arrays in a RAID controller quite often lay down some
proprietary infrastructure. So if you take that drive out of the RAID
controller and insert to JBOD, it cannot be read. For example, create a
single drive RAID 0 in a Compaq SmartArray 5Si and then try to read on an
Adaptec 39160. It doesn't work.
> What the hell is a "SATA JBOD controller".
> There is JBOD as in "a JBOD cabinet" and there is JBOD as in "a JBOD
> array", which is a RAID mode.
An example of a SATA JBOD controller would be any SATA controller that does
support hardware RAID. For example a Silicon Image 3512 card that does not
support hardware RAID is here:
>What the hell is a "SATA JBOD controller".
>There is JBOD as in "a JBOD cabinet" and there is JBOD as in "a JBOD array", which is a RAID mode.
>
Ah, Folkert, getting your definitions from Wikipedia again, I see.
JBOD has historically referred to a collection of otherwise unrelated spindles. There
have recently been some definitions that imply that JBOD is a degenerate RAID-0 (with
stripe size == spindle size), but that's not the traditional definition of JBOD.
Re: Looking for SAS/SATA RAID Controller That Supports JBOD
"Scott Lurndal" <scott@slp53.sl.home> wrote in message
news:wibqi.46063$YL5.17139@newssvr29.news.prodigy. net...
> JBOD has historically referred to a collection of otherwise unrelated
> spindles. There
> have recently been some definitions that imply that JBOD is a degenerate
> RAID-0 (with
> stripe size == spindle size), but that's not the traditional definition of
> JBOD.
And even if you want to go with the idea that JBOD is a special case of RAID
0, that is a *logical* construct, and the unfortunate reality is that it is
not only useless but outright misleading when you start to work with
real-world equipment.
The first time I encountered a single adapter that could actually switch
between hardware RAID and true JBOD was using the Intel chipset RAID that is
used in the Dell Precision workstations. It's wonderful and very useful
to work simultaneously with real JBOD and hardware RAID volumes, on the same
controller. But that's the first time I had seen it done successfully
in 15 years of working with hardware RAID controllers.
Re: Looking for SAS/SATA RAID Controller That Supports JBOD
Scott Lurndal wrote:
>
> JBOD has historically referred to a collection of otherwise unrelated spindles. There
> have recently been some definitions that imply that JBOD is a degenerate RAID-0 (with
> stripe size == spindle size), but that's not the traditional definition of JBOD.
I also know "JBOD" as the latter case (linear chain of disks without
striping). Such a JBOD is indeed no RAID, but the same is true for RAID0
(also has no redundancy for what the "R" in RAID stands for). The
correct names may be "chaining" and "striping", "RAID" only for
redundant arrays.
Re: Looking for SAS/SATA RAID Controller That Supports JBOD
"Will" <westes-usc@noemail.nospam> wrote in message news:YfidnTmNerHr2jTbnZ2dnUVZ_t-gnZ2d@giganews.com
> "Scott Lurndal" <scott@slp53.sl.home> wrote in message news:wibqi.46063$YL5.17139@newssvr29.news.prodigy. net...
> > JBOD has historically referred to a collection of otherwise unrelated
> > spindles.
Right, which is why one speaks of a JBOD cabinet, not a JBOD drive.
Just that a JBOD cabinet houses Just a Bunch Of Drives doesn't
mean that you must call every single drive a JBOD.
A drive is a drive, as in single. JBOD is plural.
> > There have recently been some definitions that imply
Since when do definitions 'imply' anything.
> > that JBOD is a degenerate RAID-0 (with stripe size == spindle size),
Nonsense. There is nothing RAID0 about JBOD arrays.
> but that's not the traditional definition of JBOD.
No kidding. I didn't say it was, now did I.
I said that there are 2 definitions, depending on what you speak of:
Cabinets (non RAID) or Array controllers (RAID)
> And even if you want to go with the idea that JBOD is a special case of RAID 0,
It isn't. That's Lurndahl's clueless idea of it.
It's JBOD, an ARRAY of Just a Bunch Of (concatenated, spanned) Drives.
Which actually makes a hell of alot more sense than a "Just a Bunch Of Drives" drive.
If JBOD would be a single drive they would have called it a JASD, not a JBOD.
> that is a *logical* construct,
Which can exist of only a single drive, so not necessarily.
> and the unfortunate reality is that it is not only useless
Oh, why?
> but outright misleading when you start to work with real-world equipment.
Utter bloody nonsense.
What the hell is "real-world equipment". Is there any other? Imaginary?
>
> The first time I encountered a single adapter that could actually switch
> between hardware RAID and true JBOD was using the Intel chipset RAID that is
> used in the Dell Precision workstations. It's wonderful and very useful
> to work simultaneously with real JBOD and hardware RAID volumes, on the same
> controller. But that's the first time I had seen it done successfully
> in 15 years of working with hardware RAID controllers.
Re: Looking for SAS/SATA RAID Controller That Supports JBOD
"Will" <westes-usc@noemail.nospam> wrote in message news:b_idnUNQkYKIsjTbnZ2dnUVZ_vamnZ2d@giganews.com
> "Folkert Rienstra" <see_reply-to@myweb.nl> wrote in message news:46a92b0e$0$97248$892e7fe2@authen.yellow.readf reenews.net...
> > "Will" westes-usc@noemail.nospam> wrote in message news:fYOdnbxdC-8YdTXbnZ2dnUVZ_u2mnZ2d@giganews.com
> > > I'm looking for a SAS/SATA RAID controller (preferably with a decent
> > > battery
> > > backed cache)
> >
> > > that has a mode to support JBOD for mounting individual physical SATA
> > > drives.
> >
> > Are there any that don't?
> 95% of them yes.
Good. So you already know the 5% that do then.
>
>
> > > I am NOT looking for RAID 0 support on a single drive.
> >
> > Why not? Is there a problem with that? What's the difference.
>
> Single drive RAID 0 arrays in a RAID controller quite often lay down some
> proprietary infrastructure.
Right, how else to distinguish it as 'RAID0', single drive or otherwise.
The point is, will this infrastructure interfere with the filesystem struc-
ture on the drive. It doesn't need to if it is kept at the end of the drive.
Keeping this info at the beginning of the drive in places that are normally
reserved for partition and file system info is ancient.
> So if you take that drive out of the RAID
> controller and insert to JBOD, it cannot be read.
Which means that you have one of those more proprietary controllers that
say that you are ****ed if the controller dies, because of the offset loca-
tions for the filesystem and partition structures.
With RAID systems that keep this data on the last track (or anywhere in
places not used by file-systems) the drives may well be read on a system
with software RAID, if the controller dies.
> For example, create a single drive RAID 0 in a Compaq SmartArray 5Si
> and then try to read on an Adaptec 39160. It doesn't work.
So the SmartArray 5Si is to be avoided.
And likely the rest of the Compaq range too.
>
> > What the hell is a "SATA JBOD controller".
> > There is JBOD as in "a JBOD cabinet" and there is JBOD as in "a JBOD
> > array", which is a RAID mode.
> An example of a SATA JBOD controller would be any SATA controller that does
> support hardware RAID.
Obviously you are confused. Just above you said 95% of them don't support JBOD.
Re: Looking for SAS/SATA RAID Controller That Supports JBOD
"Folkert Rienstra" <see_reply-to@myweb.nl> wrote in message
news:46aaecbf$1$97270$892e7fe2@authen.yellow.readf reenews.net...
> "Will" <westes-usc@noemail.nospam> wrote in message
news:YfidnTmNerHr2jTbnZ2dnUVZ_t-gnZ2d@giganews.com
> > "Scott Lurndal" <scott@slp53.sl.home> wrote in message
news:wibqi.46063$YL5.17139@newssvr29.news.prodigy. net...
> > > JBOD has historically referred to a collection of otherwise unrelated
> > > spindles.
>
> Right, which is why one speaks of a JBOD cabinet, not a JBOD drive.
I said a JBOD controller, not a JBOD drive. You could also refer to such
a controller as a non-RAID controller.
> > but that's not the traditional definition of JBOD.
>
> No kidding. I didn't say it was, now did I.
> I said that there are 2 definitions, depending on what you speak of:
> Cabinets (non RAID) or Array controllers (RAID)
If you are trying to make some idea clear, you are not. You keep
responding to points people are not making and making your own points that
do not contradict the original points made.
Which of these do you not agree with:
1) There are drive cabinets that have controllers and there are drive
cabinets that do not have controllers.
2) When a drive cabinet has a controller, it is usually a hardware RAID
controller.
3) When a drive cabinet does not have a controller, it usually has a pass
through connection to a controller that runs on the host computer.
4) A host computer controller can be a RAID controller.
5) A host computer controller can be a non RAID controller.
Host-based controller cards of type 5) are normally referred to as JBOD
controllers. If you want to create a differernt name, okay, but at least
show you can follow the topic and put a name to the thing in 5) It has
nothing to do with host cabinets, and it's a complete distraction to this
thread that you keep responding to questions and points about 5) with a
diatribe about points 1), 2), and 3).
> > and the unfortunate reality is that it is not only useless
>
> Oh, why?
>
> > but outright misleading when you start to work with real-world
equipment.
>
> Utter bloody nonsense.
> What the hell is "real-world equipment". Is there any other? Imaginary?
With all due respect, stop wasting people's time here with all of this idle
speculation. Get a real controller. Do a real experiment. Get some
real world experience. Then you can come back and rename the phenomena
what you wish to name it.
For a real experiment, pick up a Compaq SmartArray 5Si which is a RAID SCSI
controller. Create a single drive RAID 0 array on the SmartArray. Format
the drive and put some OS or data on it.
Remove that drive and stick it onto an an Adaptec 31960 "JBOD controller"
which is a non-RAID SCSI controller. You will not be able to read the
drive.
Compare that to creating the same drive on a different brand (LSI Logic, for
example) of non RAID SCSI controller. You can freely pass that drive
across many different makes and models of non RAID controllers.
The hardware RAID controller lays down some kind of proprietary information
that prevents it from being read cleanly on any other non RAID controller.
Regardless of what words you want to use to describe the non-RAID
controller, it is the portability of single drives across such controllers
that I am seeking. And it makes you look like you have no real world
experience at all if you cannot relate to what that means or give words to
it. And it makes it look like you you don't follow the topic at all to be
arguing about JBOD cabinets.
Looking for SAS/SATA RAID Controller That Supports JBOD 
Linear Mode
