On Fri, Jun 27, 2008 at 7:00 AM, Matthew Wakeling <[EMAIL PROTECTED]> wrote:
> On Thu, 26 Jun 2008, Merlin Moncure wrote:
>>
>> In addition there are many different types of flash (MLC/SLC) and the
>> flash cells themselves can be organized in particular ways involving various
>> trade-offs.
>
> Ye
On Thu, 26 Jun 2008, Merlin Moncure wrote:
In addition there are many different types of flash (MLC/SLC) and the
flash cells themselves can be organized in particular ways involving
various trade-offs.
Yeah, I wouldn't go for MLC, given it has a tenth the lifespan of SLC.
The main issue is lo
On Wednesday 25 June 2008 11:24:23 Greg Smith wrote:
> What I often do is get a hardware RAID controller, just to accelerate disk
> writes, but configure it in JBOD mode and use Linux or other software RAID
> on that platform.
>
JBOD + RAIDZ2 FTW ;-)
--
Robert Treat
Build A Brighter LAMP :: Linu
On Thu, 26 Jun 2008, Peter T. Breuer wrote:
Double buffering is a killer.
No, it isn't; it's a completely trivial bit of overhead. It only exists
during the time when blocks are queued to write but haven't been written
yet. On any database system, in those cases I/O congestion at the disk
On Thu, 26 Jun 2008, Peter T. Breuer wrote:
"Also sprach Merlin Moncure:"
The linux software raid algorithms are highly optimized, and run on a
I can confidently tell you that that's balderdash both as a Linux author
and as a software RAID linux author (check the attributions in the
kernel so
On Thu, Jun 26, 2008 at 1:03 AM, Peter T. Breuer <[EMAIL PROTECTED]> wrote:
> "Also sprach Merlin Moncure:"
>> write back: raid controller can lie to host o/s. when o/s asks
>
> This is not what the linux software raid controller does, then. It
> does not queue requests internally at all, nor ack r
"Also sprach Merlin Moncure:"
> write back: raid controller can lie to host o/s. when o/s asks
This is not what the linux software raid controller does, then. It
does not queue requests internally at all, nor ack requests that have
not already been acked by the components (modulo the fact that on
On Thu, Jun 26, 2008 at 12:14 PM, Matthew Wakeling <[EMAIL PROTECTED]> wrote:
>> None of these manufacturers rates these drives for massive amounts of
>> writes. They're sold as suitable for laptop/desktop use, which normally is
>> not a heavy wear and tear operation like a DB. Once they claim sui
On Thu, Jun 26, 2008 at 9:49 AM, Peter T. Breuer <[EMAIL PROTECTED]> wrote:
> "Also sprach Merlin Moncure:"
>> As discussed down thread, software raid still gets benefits of
>> write-back caching on the raid controller...but there are a couple of
>
> (I wish I knew what write-back caching was!)
ha
On Thu, Jun 26, 2008 at 10:14 AM, Matthew Wakeling <[EMAIL PROTECTED]> wrote:
> On Thu, 26 Jun 2008, Vivek Khera wrote:
>>>
>>> Anyone have experience with IDE, SATA, or SAS-connected flash devices
>>> like the Samsung MCBQE32G5MPP-0VA? I mean, it seems lovely - 32GB, at a
>>> transfer rate of 100M
On Thu, 26 Jun 2008, Vivek Khera wrote:
Anyone have experience with IDE, SATA, or SAS-connected flash devices like
the Samsung MCBQE32G5MPP-0VA? I mean, it seems lovely - 32GB, at a transfer
rate of 100MB/s, and doesn't degrade much in performance when writing small
random blocks. But what's it
On Jun 25, 2008, at 11:35 AM, Matthew Wakeling wrote:
On Wed, 25 Jun 2008, Greg Smith wrote:
A firewire-attached log device is an extremely bad idea.
Anyone have experience with IDE, SATA, or SAS-connected flash
devices like the Samsung MCBQE32G5MPP-0VA? I mean, it seems lovely -
32GB, a
On Wed, 25 Jun 2008, Andrew Sullivan wrote:
the key thing to do is to ensure you have good testing infrastructure in
place to check that things will work before you deploy to production.
This is true whether you're using Linux or completely closed source
software. There are two main differen
On Wed, 25 Jun 2008, Merlin Moncure wrote:
So, based on this and other experiences, i'm starting to be more partial
to linux distributions with faster moving kernels, mainly because i
trust the kernel drivers more than the vendor provided drivers.
Depends on how fast. I find it takes a minim
On Wed, 25 Jun 2008, Peter T. Breuer wrote:
I refrained from saying in my reply that I would set up a firewire-based
link to ram in a spare old portable (which comes with a battery) if I
wanted to do this cheaply.
Maybe, but this is kind of a weird setup. Not many people are going to
run a p
On Wed, Jun 25, 2008 at 01:07:25PM -0500, Kevin Grittner wrote:
>
> It doesn't have to be free software to cut that way. I've actually
> found the free software to waste less of my time.
No question. But one of the unfortunate facts of the
no-charge-for-licenses world is that many people exp
>>> Andrew Sullivan <[EMAIL PROTECTED]> wrote:
> this is a blade that cuts both ways, and the key thing to do is
> to ensure you have good testing infrastructure in place to check
that
> things will work before you deploy to production. (The other way to
> say that, of course, is "Linux is only
On Wed, Jun 25, 2008 at 01:35:49PM -0400, Merlin Moncure wrote:
> experiences, i'm starting to be more partial to linux distributions
> with faster moving kernels, mainly because i trust the kernel drivers
> more than the vendor provided drivers.
While I have some experience that agrees with this,
On Wed, Jun 25, 2008 at 9:03 AM, Matthew Wakeling <[EMAIL PROTECTED]> wrote:
> On Wed, 25 Jun 2008, Merlin Moncure wrote:
>>>
>>> Has anyone done some benchmarks between hardware RAID vs Linux MD
>>> software
>>> RAID?
>>
>> I have here:
>>
>> http://merlinmoncure.blogspot.com/2007/08/following-are
On Wed, Jun 25, 2008 at 11:55 AM, Joshua D. Drake <[EMAIL PROTECTED]> wrote:
> On Wed, 2008-06-25 at 09:53 -0600, Scott Marlowe wrote:
>> On Wed, Jun 25, 2008 at 5:05 AM, Adrian Moisey
>> <[EMAIL PROTECTED]> wrote:
>
>> I'm currently having a problem with a "well known very large
>> servermanufactu
"Also sprach Greg Smith:"
> On Wed, 25 Jun 2008, Peter T. Breuer wrote:
>
> > You can put the log/bitmap wherever you want in software raid, including
> > on a battery-backed local ram disk if you feel so inclined. So there is
> > no intrinsic advantage to be gained there at all.
>
> You are t
On Wed, 2008-06-25 at 09:53 -0600, Scott Marlowe wrote:
> On Wed, Jun 25, 2008 at 5:05 AM, Adrian Moisey
> <[EMAIL PROTECTED]> wrote:
> > Hi
> I'm currently having a problem with a "well known very large
> servermanufacturer who shall remain unnamed" and their semi-custom
> RAID controller firmw
On Wed, Jun 25, 2008 at 5:05 AM, Adrian Moisey
<[EMAIL PROTECTED]> wrote:
> Hi
>
> Has anyone done some benchmarks between hardware RAID vs Linux MD software
> RAID?
>
> I'm keen to know the result.
I've had good performance from sw RAID-10 in later kernels, especially
if it was handling a mostly
On Wed, 25 Jun 2008, Greg Smith wrote:
A firewire-attached log device is an extremely bad idea.
Anyone have experience with IDE, SATA, or SAS-connected flash devices like
the Samsung MCBQE32G5MPP-0VA? I mean, it seems lovely - 32GB, at a
transfer rate of 100MB/s, and doesn't degrade much in p
On Wed, 2008-06-25 at 11:30 -0400, Jonah H. Harris wrote:
> On Wed, Jun 25, 2008 at 11:24 AM, Greg Smith <[EMAIL PROTECTED]> wrote:
> > SMART doesn't detect 100% of drive failures in advance, but you'd be silly
> > to setup a database system where you don't get to take advantage of the
> > ~50% i
On Wed, Jun 25, 2008 at 11:24 AM, Greg Smith <[EMAIL PROTECTED]> wrote:
> SMART doesn't detect 100% of drive failures in advance, but you'd be silly
> to setup a database system where you don't get to take advantage of the
> ~50% it does catch before you lose any data.
Can't argue with that one.
On Wed, 25 Jun 2008, Peter T. Breuer wrote:
You can put the log/bitmap wherever you want in software raid, including
on a battery-backed local ram disk if you feel so inclined. So there is
no intrinsic advantage to be gained there at all.
You are technically correct but this is irrelevant.
"Also sprach Matthew Wakeling:"
> >> Has anyone done some benchmarks between hardware RAID vs Linux MD software
> >> RAID?
...
> > The upshot is I don't really see a difference in performance.
>
> The main difference is that you can get hardware RAID with
> battery-backed-up cache, which means
On Wed, 25 Jun 2008, Merlin Moncure wrote:
Has anyone done some benchmarks between hardware RAID vs Linux MD software
RAID?
I have here:
http://merlinmoncure.blogspot.com/2007/08/following-are-results-of-our-testing-of.html
The upshot is I don't really see a difference in performance.
The ma
On Wed, Jun 25, 2008 at 7:05 AM, Adrian Moisey
<[EMAIL PROTECTED]> wrote:
> Has anyone done some benchmarks between hardware RAID vs Linux MD software
> RAID?
>
> I'm keen to know the result.
I have here:
http://merlinmoncure.blogspot.com/2007/08/following-are-results-of-our-testing-of.html
I als
Hi
Has anyone done some benchmarks between hardware RAID vs Linux MD
software RAID?
I'm keen to know the result.
--
Adrian Moisey
Systems Administrator | CareerJunction | Your Future Starts Here.
Web: www.careerjunction.co.za | Email: [EMAIL PROTECTED]
Phone: +27 21 686 6820 | Mobile: +27 82
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