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Old 02-10-2010, 10:14 AM
"J. Roeleveld"
 
Default 1-Terabyte drives - 4K sector sizes? -> bar performance so far

On Wednesday 10 February 2010 02:28:59 Stroller wrote:
> On 9 Feb 2010, at 19:37, J. Roeleveld wrote:
> > ...
> > Don't get me started on those
> > The reason I use Linux Software Raid is because:
> > 1) I can't afford hardware raid adapters
> > 2) It's generally faster then hardware fakeraid
>
> I'd rather have slow hardware RAID than fast software RAID. I'm not
> being a snob, it just suits my purposes better.

I don't consider that comment as "snobbish" as I actually agree.
But as I am using 6 disks in the array, a hardware RAID card to handle that
would have pushed me above budget.
It is planned for a future upgrade (along with additional disks), but that
will have to wait till after another few expenses.

> If speed isn't an issue then secondhand prices of SATA RAID
> controllers (PCI & PCI-X form-factor) are starting to become really
> cheap. Obviously new cards are all PCI-e - industry has long moved to
> that, and enthusiasts are following.

My mainboard has PCI, PCI-X and PCI-e (1x and 16x), which connector-type would
be best suited?
Also, I believe a PCI-e 8x card would work in a PCI-e 16x slot, but does this
work with all mainboards/cards? Or are some more picky about this?

> I would be far less invested in hardware RAID if I could find regular
> SATA controllers which boasted hot-swap. I've read reports of people
> hot-swapping SATA drives "just fine" on their cheap controllers but
> last time I checked there were no manufacturers who supported this as
> a feature.

The mainboard I use (ASUS M3N-WS) has a working hotswap support (Yes, I tested
this) using hotswap drive bays.
Take a disk out, Linux actually sees it being removed prior to writing to it
and when I stick it back in, it gets a new device assigned.

On a different machine, where I tried it, the whole machine locked up when I
removed the disk (And SATA is supposed to be hotswappable by design...)

--
Joost
 
Old 02-10-2010, 10:17 AM
"J. Roeleveld"
 
Default 1-Terabyte drives - 4K sector sizes? -> bar performance so far

On Wednesday 10 February 2010 12:03:51 Volker Armin Hemmann wrote:
> On Mittwoch 10 Februar 2010, J. Roeleveld wrote:
> > As for recovery, I always use "sysrescuecd" (http://www.sysresccd.org)
> > and this has Raid and LVM support in it. (Same with the Gentoo-livecds)
>
> sysrescuecd failed me hard two nights ago. 64bit kernel paniced with stack
> corruptions, 32bit kernel took an hour to unpack 300kb from a 20gb tar...
>
> it was pathetic...
>

Never had a problem with it myself, but I always test rescuediscs semi-
regularly on all my machines, just to be sure.

I'm also paranoid when it comes to backups of my private data.
 
Old 02-10-2010, 10:24 AM
Volker Armin Hemmann
 
Default 1-Terabyte drives - 4K sector sizes? -> bar performance so far

On Mittwoch 10 Februar 2010, J. Roeleveld wrote:
> On Wednesday 10 February 2010 12:03:51 Volker Armin Hemmann wrote:
> > On Mittwoch 10 Februar 2010, J. Roeleveld wrote:
> > > As for recovery, I always use "sysrescuecd" (http://www.sysresccd.org)
> > > and this has Raid and LVM support in it. (Same with the Gentoo-livecds)
> >
> > sysrescuecd failed me hard two nights ago. 64bit kernel paniced with
> > stack corruptions, 32bit kernel took an hour to unpack 300kb from a 20gb
> > tar...
> >
> > it was pathetic...
>
> Never had a problem with it myself, but I always test rescuediscs semi-
> regularly on all my machines, just to be sure.
>
> I'm also paranoid when it comes to backups of my private data.

because of my backup harddisk (I first copy everything on a seperate disk, then
later the important stuff onto tapes), I was able to boot into a pretty actual
system and untar from their. And suddenly I was hitting 100mb/sec+ writing
speed...
 
Old 02-10-2010, 03:37 PM
Stroller
 
Default 1-Terabyte drives - 4K sector sizes? -> bar performance so far

On 10 Feb 2010, at 11:14, J. Roeleveld wrote:


On Wednesday 10 February 2010 02:28:59 Stroller wrote:

On 9 Feb 2010, at 19:37, J. Roeleveld wrote:

...
Don't get me started on those
The reason I use Linux Software Raid is because:
1) I can't afford hardware raid adapters
2) It's generally faster then hardware fakeraid


I'd rather have slow hardware RAID than fast software RAID. I'm not
being a snob, it just suits my purposes better.


I don't consider that comment as "snobbish" as I actually agree.
But as I am using 6 disks in the array, a hardware RAID card to
handle that

would have pushed me above budget.


See, for example, eBay item 280459693053.

LSI is also a popular brand amongst Linux enthusiasts.

3ware have been taken over by LSI and their support has deteriorated
over the last few months, but 3ware cards come with transferrable 3
year warranty, expiry date identifiable by serial number, and you will
often find eBay cards are still in warranty.


It is planned for a future upgrade (along with additional disks),
but that

will have to wait till after another few expenses.


If speed isn't an issue then secondhand prices of SATA RAID
controllers (PCI & PCI-X form-factor) are starting to become really
cheap. Obviously new cards are all PCI-e - industry has long moved to
that, and enthusiasts are following.


My mainboard has PCI, PCI-X and PCI-e (1x and 16x), which connector-
type would

be best suited?


PCI-e, PCI-X, PCI in that order, I *think*.

PCI-X is very good, IIRC, it may be fractionally faster than PCI-e,
but I get the impression it's going out of fashion a bit on
motherboards.


PCI-e is very fast and is the most readily usable on new & future
motherboards. It is what one would choose if buying new (I'm not sure
if PCI-X cards are still available), and so it is the most expensive
on the secondhand market.


Some 3ware PCI-X cards (eg the 9500S at least) are usable in regular
PCI slots, obviously at the expense of speed. Not sure about other
brands.


Avoid 3ware 7000 & 8000 series cards - they are now ancient, although
you can pick them up for 10.


Also, I believe a PCI-e 8x card would work in a PCI-e 16x slot, but
does this

work with all mainboards/cards? Or are some more picky about this?


No idea, sorry. I would have thought so, but I don't use PCI-e here yet.


I would be far less invested in hardware RAID if I could find regular
SATA controllers which boasted hot-swap. I've read reports of people
hot-swapping SATA drives "just fine" on their cheap controllers but
last time I checked there were no manufacturers who supported this as
a feature.


The mainboard I use (ASUS M3N-WS) has a working hotswap support
(Yes, I tested

this) using hotswap drive bays.
Take a disk out, Linux actually sees it being removed prior to
writing to it

and when I stick it back in, it gets a new device assigned.


This is very interesting to know.

This would be very useful here, even if just for auxiliary use -
swapping in a drive from another machine just to clone it, backup or
recover data, for instance.


If I found an Atom-based board that did hotswap on its normal SATA
ports I would probably purchase one in a flash.


On a different machine, where I tried it, the whole machine locked
up when I
removed the disk (And SATA is supposed to be hotswappable by
design...)


This is what I would normally expect, at least from when I last
checked a year or two ago.


AIUI SATA by design *may* be hotswappable at the *option* of the
manufacturer.

(Please correct me if I am mistaken)

Stroller.
 
Old 02-10-2010, 04:26 PM
"J. Roeleveld"
 
Default 1-Terabyte drives - 4K sector sizes? -> bar performance so far

On Wednesday 10 February 2010 17:37:47 Stroller wrote:
> On 10 Feb 2010, at 11:14, J. Roeleveld wrote:
> > On Wednesday 10 February 2010 02:28:59 Stroller wrote:
> >> On 9 Feb 2010, at 19:37, J. Roeleveld wrote:
> >>> ...
> >>> Don't get me started on those
> >>> The reason I use Linux Software Raid is because:
> >>> 1) I can't afford hardware raid adapters
> >>> 2) It's generally faster then hardware fakeraid
> >>
> >> I'd rather have slow hardware RAID than fast software RAID. I'm not
> >> being a snob, it just suits my purposes better.
> >
> > I don't consider that comment as "snobbish" as I actually agree.
> > But as I am using 6 disks in the array, a hardware RAID card to
> > handle that
> > would have pushed me above budget.
>
> See, for example, eBay item 280459693053.
>
> LSI is also a popular brand amongst Linux enthusiasts.
>
> 3ware have been taken over by LSI and their support has deteriorated
> over the last few months, but 3ware cards come with transferrable 3
> year warranty, expiry date identifiable by serial number, and you will
> often find eBay cards are still in warranty.

Yes, except that I tend to avoid eBay as much as possible for reasons that
don't belong on this list.

> > My mainboard has PCI, PCI-X and PCI-e (1x and 16x), which connector-
> > type would
> > be best suited?
>
> PCI-e, PCI-X, PCI in that order, I *think*.
>
> PCI-X is very good, IIRC, it may be fractionally faster than PCI-e,
> but I get the impression it's going out of fashion a bit on
> motherboards.
>
> PCI-e is very fast and is the most readily usable on new & future
> motherboards. It is what one would choose if buying new (I'm not sure
> if PCI-X cards are still available), and so it is the most expensive
> on the secondhand market.

I know at least one shop in NL that sells them (They're also online)

> Some 3ware PCI-X cards (eg the 9500S at least) are usable in regular
> PCI slots, obviously at the expense of speed. Not sure about other
> brands.
>
> Avoid 3ware 7000 & 8000 series cards - they are now ancient, although
> you can pick them up for 10.
>
> > Also, I believe a PCI-e 8x card would work in a PCI-e 16x slot, but
> > does this
> > work with all mainboards/cards? Or are some more picky about this?
>
> No idea, sorry. I would have thought so, but I don't use PCI-e here yet.

It's what all the buzz says, but I've yet to have that confirmed. It's
especially the size of the slots and the cards where my concerns come from.

> >> I would be far less invested in hardware RAID if I could find regular
> >> SATA controllers which boasted hot-swap. I've read reports of people
> >> hot-swapping SATA drives "just fine" on their cheap controllers but
> >> last time I checked there were no manufacturers who supported this as
> >> a feature.
> >
> > The mainboard I use (ASUS M3N-WS) has a working hotswap support
> > (Yes, I tested
> > this) using hotswap drive bays.
> > Take a disk out, Linux actually sees it being removed prior to
> > writing to it
> > and when I stick it back in, it gets a new device assigned.
>
> This is very interesting to know.
>
> This would be very useful here, even if just for auxiliary use -
> swapping in a drive from another machine just to clone it, backup or
> recover data, for instance.

Yes, but just for cloning, wouldn't it be just as easy to power down the
machine, plug in the drive and then power it back up?
Or even stick it on a quick-change USB-case?

> If I found an Atom-based board that did hotswap on its normal SATA
> ports I would probably purchase one in a flash.
>
> > On a different machine, where I tried it, the whole machine locked
> > up when I
> > removed the disk (And SATA is supposed to be hotswappable by
> > design...)
>
> This is what I would normally expect, at least from when I last
> checked a year or two ago.

I do have to say here that the mainboard for that machine is now easily 5
years old, so I didn't actually expect it to work.

> AIUI SATA by design *may* be hotswappable at the *option* of the
> manufacturer.
> (Please correct me if I am mistaken)

I think it depends on if the controller actually sends the correct signals to
the OS as I'm not sure if it was Linux or the hardware locking up.
 
Old 02-10-2010, 07:48 PM
Stroller
 
Default 1-Terabyte drives - 4K sector sizes? -> bar performance so far

On 10 Feb 2010, at 17:26, J. Roeleveld wrote:

...
The mainboard I use (ASUS M3N-WS) has a working hotswap support
(Yes, I tested
this) using hotswap drive bays.
Take a disk out, Linux actually sees it being removed prior to
writing to it
and when I stick it back in, it gets a new device assigned.


This is very interesting to know.

This would be very useful here, even if just for auxiliary use -
swapping in a drive from another machine just to clone it, backup or
recover data, for instance.


Yes, but just for cloning, wouldn't it be just as easy to power down
the

machine, plug in the drive and then power it back up?
Or even stick it on a quick-change USB-case?


I'd really rather not power the machine down. Likely it's in the
middle of a 24-hour DVD rip, or something.


A quick-change USB-case (or similar) is the current method, but I have
4 spare hot-swap bays on the front of this box, so slapping the drive
in one of those reduces the clutter in the server cabinet. And that
does have a tendency to get VERY cluttered, so if I can reduce that it
also reduces the potential for human errors (pulling the wrong USB
cable by mistake &c).


Stroller.
 
Old 02-12-2010, 08:06 AM
Mick
 
Default 1-Terabyte drives - 4K sector sizes? -> bar performance so far

On Tuesday 09 February 2010 16:31:15 Mark Knecht wrote:
> On Mon, Feb 8, 2010 at 4:37 PM, Mark Knecht <markknecht@gmail.com> wrote:
> <SNIP>
>
> > There's a few small downsides I've run into with all of this so far:
> >
> > 1) Since we don't use sector 63 it seems that fdisk will still tell
> > you that you can use 63 until you use up all your primary partitions.
> > It used to be easier to put additional partitions on when it gave you
> > the next sector you could use after the one you just added.. Now I'm
> > finding that I need to write things down and figure it out more
> > carefully outside of fdisk.
>
> Replying mostly to myself, WRT the value 63 continuing to show up
> after making the first partition start at 64, in my case since for
> desktop machines the first partition is general /boot, and as it's
> written and read so seldom, in the future when faced with this problem
> I will likely start /boot at 63 and just ensure that all the other
> partitions - /, /var, /home, etc., start on boundaries divisible by 8.
>
> It will make using fdisk slightly more pleasant.

I noticed while working on two new laptops with gparted that resizing Windows
7 and creating new partitions showed up small blank partitions (marked as
hidden) in between the resized, and/or the new partitions. If I recall
correctly these were only a few KB each so rather small as such. I am not
sure why gparted created these - could it be related to the drive
automatically aligning partitions to this 4K sector size that is discussed
here?
--
Regards,
Mick
 
Old 02-14-2010, 11:48 PM
Frank Steinmetzger
 
Default 1-Terabyte drives - 4K sector sizes? -> bar performance so far

Am Sonntag, 7. Februar 2010 schrieb Mark Knecht:

> Hi Willie,
> OK - it turns out if I start fdisk using the -u option it show me
> sector numbers. Looking at the original partition put on just using
> default values it had the starting sector was 63 - probably about the
> worst value it could be. As a test I blew away that partition and
> created a new one starting at 64 instead and the untar results are
> vastly improved - down to roughly 20 seconds from 8-10 minutes. That's
> roughly twice as fast as the old 120GB SATA2 drive I was using to test
> the system out while I debugged this issue.

Sorry if I reheat a topic that some already consider closed. I used the
weekend to experiment on that stuff and need to report my results. Because
they startle me a little.

I first tried different start sectors around sector 63: 63, 64, 66, 68 etc.
They showed nearly the same results in speed. So I almost thought that my
drive, albeit being new and of high capacity, is not affected by this yet.

But then I tested my main media partition, which starts in the middle of the
disk. I downloaded a portage snapshot and put it into a ramdisk, so reading
it would not manipulate measurements. I also copied a 1GB file into that
ramdisk to test consecutive writes.

As a start sector I chose 288816640, which is divisible by 64. The startling
result: this gave the lowest performance. If the partition starts in one of
the sectors behind it, performance was always better. I repeated the test
several times to confirm it. How do you explain this? :-?

The following table shows the ‘real’ value from the output of the time
command. SS means the aforementioned start sector with SS % 64 == 0.

action SS (1st) SS (2nd) SS+2 SS+4 SS+6 SS+8
-------------+----------+----------+----------+----------+----------+----------
untar portage 3m12.517 2m55.916 1m46.663 1m35.341 1m47.829 1m43.677
rm portage 4m11.109 3m54.950 3m18.820 3m11.378 3m21.804 3m12.433
cp 1GB file 0m21.383 0m13.558 0m14.920 0m12.813 0m13.407 0m13.681

--
Gruß | Greetings | Qapla'
How are things in the collective?" - "Perfect."
(Captain Jainway to the Borg queen)
 
Old 02-15-2010, 12:17 AM
Willie Wong
 
Default 1-Terabyte drives - 4K sector sizes? -> bar performance so far

On Mon, Feb 15, 2010 at 01:48:01AM +0100, Frank Steinmetzger wrote:
> Sorry if I reheat a topic that some already consider closed. I used the
> weekend to experiment on that stuff and need to report my results. Because
> they startle me a little.
>
> I first tried different start sectors around sector 63: 63, 64, 66, 68 etc.
> They showed nearly the same results in speed. So I almost thought that my
> drive, albeit being new and of high capacity, is not affected by this yet.
>
> But then I tested my main media partition, which starts in the middle of the
> disk. I downloaded a portage snapshot and put it into a ramdisk, so reading
> it would not manipulate measurements. I also copied a 1GB file into that
> ramdisk to test consecutive writes.
>
> As a start sector I chose 288816640, which is divisible by 64. The startling
> result: this gave the lowest performance. If the partition starts in one of
> the sectors behind it, performance was always better. I repeated the test
> several times to confirm it. How do you explain this? :-?
>
> The following table shows the ‘real’ value from the output of the time
> command. SS means the aforementioned start sector with SS % 64 == 0.
>
> action SS (1st) SS (2nd) SS+2 SS+4 SS+6 SS+8
> -------------+----------+----------+----------+----------+----------+----------
> untar portage 3m12.517 2m55.916 1m46.663 1m35.341 1m47.829 1m43.677
> rm portage 4m11.109 3m54.950 3m18.820 3m11.378 3m21.804 3m12.433
> cp 1GB file 0m21.383 0m13.558 0m14.920 0m12.813 0m13.407 0m13.681

Instead of guessing using this rather imprecise metric, why not just
look up the serial number of your drive and see what the physical
sector size is? If you don't want to open your box, you can usually
get the information from dmesg.

Only caveat: don't trust the harddrive to report accurate geometry.
This whole issue is due to the harddrives lying about their physical
geometry to be compatible with older versions of Windows. So the
physical sector size listed in dmesg may not be the real one. Which is
why you are advised to look up the model number on the vendor's
website yourself to determine the physical sector size.

W
--
Willie W. Wong wwong@math.princeton.edu
Data aequatione quotcunque fluentes quantitae involvente fluxiones invenire
et vice versa ~~~ I. Newton
 
Old 02-15-2010, 05:03 PM
Frank Steinmetzger
 
Default 1-Terabyte drives - 4K sector sizes? -> bar performance so far

Am Montag, 15. Februar 2010 schrieb Willie Wong:
> On Mon, Feb 15, 2010 at 01:48:01AM +0100, Frank Steinmetzger wrote:
> > Sorry if I reheat a topic that some already consider closed. I used the
> > weekend to experiment on that stuff and need to report my results.
> > Because they startle me a little.
> > [...]
> Instead of guessing using this rather imprecise metric, why not just
> look up the serial number of your drive and see what the physical
> sector size is?

Well, at differences of 50%, precision is of no relevance anymore.
Also, I already did look it up and it didn’t turn up any conclusive results.
Just search hits from fdisk output of people who are partitioning the drive.
So the only thing I can think of yet is to call Samsung’s expensive hotline.
Hm... oh well, perhaps I could write an e-mail, because I’m too niggard and
phonophobe to make a call. ^^

> If you don't want to open your box, you can usually
> get the information from dmesg.

I put the drive in myself after I bought it at
http://www.alternate.de/html/product/Festplatten_2,5_Zoll_SATA/Samsung/HM500JI_500_GB/342736/?showTecData=true
But they don’t show much information either. :-/
I don’t suppose it’s written on the disk’s label? I don’t wanna loosen those
screws too often, because the windings tend to wear out quickly.
--
Gruß | Greetings | Qapla'
I guess irony can be pretty ironic sometimes.
 

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