Very slow copying data from RAID 1 array.

Hi

I have a 500GB RAID1 array using brand new Western Digital drives and the
Sil 3114 chipset on my ASUS A8N-SLI Premium system board.

I use the RAID to store partition backup image files which are split into
multiple 2GB segments. The backup segments total approx 70Gb.

Each week I copy the image files to a removable hard drive which usually
takes approx 25-30mins.

However today after selecting all the segments (77GB Total) and beginning
the copy,
Windows is estimating over 200 minutes for the copying!

I had similar trouble a few months ago so ran a disc check on the RAID array
which took over 30hrs to complete! It seemed to fix whatever errors it
found as since then it ran normally taking approx 25-30mins to copy the
files.

However today the same lengthy copying problem has recurred.

Any idea what might cause this?

Right now I'm thinking I'll need to reformat the drives but I'll have to buy
another 500GB drive to painstakingly copy all the data off the RAID array
first! Bummer!

Thanks for any info.

Ian

Previously Ian R wrote:
Hi

I have a 500GB RAID1 array using brand new Western Digital drives and the
Sil 3114 chipset on my ASUS A8N-SLI Premium system board.

I use the RAID to store partition backup image files which are split into
multiple 2GB segments. The backup segments total approx 70Gb.

Each week I copy the image files to a removable hard drive which usually
takes approx 25-30mins.

However today after selecting all the segments (77GB Total) and beginning
the copy,
Windows is estimating over 200 minutes for the copying!

I had similar trouble a few months ago so ran a disc check on the RAID array
which took over 30hrs to complete! It seemed to fix whatever errors it
found as since then it ran normally taking approx 25-30mins to copy the
files.

However today the same lengthy copying problem has recurred.

Any idea what might cause this?

Right now I'm thinking I'll need to reformat the drives but I'll have to buy
another 500GB drive to painstakingly copy all the data off the RAID array
first! Bummer!

Thanks for any info.

Ian

30 min for 77GB is about 42MB/s. That is pretty good. 200 min
is about 6MB/s. Quite slow. May be PIO instead of DMA
on a disk (bad cabeling), may be excessive fragmentation.
May also be bad sectors or other disk issues.

Do not replace the disks before you have have diagnised the
problem. At the moment it need not be the disks themselves.

Arno

Arno Wagner wrote:
Previously Ian R wrote:
Hi

I have a 500GB RAID1 array using brand new Western Digital drives
and the Sil 3114 chipset on my ASUS A8N-SLI Premium system board.

I use the RAID to store partition backup image files which are split
into multiple 2GB segments. The backup segments total approx 70Gb.

Each week I copy the image files to a removable hard drive which
usually takes approx 25-30mins.

However today after selecting all the segments (77GB Total) and
beginning the copy,
Windows is estimating over 200 minutes for the copying!

I had similar trouble a few months ago so ran a disc check on the
RAID array which took over 30hrs to complete! It seemed to fix
whatever errors it found as since then it ran normally taking approx
25-30mins to copy the files.

However today the same lengthy copying problem has recurred.

Any idea what might cause this?

Right now I'm thinking I'll need to reformat the drives but I'll
have to buy another 500GB drive to painstakingly copy all the data
off the RAID array first! Bummer!

30 min for 77GB is about 42MB/s. That is pretty good. 200 min
is about 6MB/s. Quite slow. May be PIO instead of DMA on a disk

Yes.

(bad cabeling),

Or something else turned the DMA off.

may be excessive fragmentation.

Nope, you wont get that dramatic a result from that.

May also be bad sectors or other disk issues.

Yep. And the best way to check for that is the SMART report,
after breaking the RAID array if necessary to do that.

Do not replace the disks before you have have diagnised the
problem. At the moment it need not be the disks themselves.

"Arno Wagner" wrote in message
...
Previously Ian R wrote:
Hi

I have a 500GB RAID1 array using brand new Western Digital drives and the
Sil 3114 chipset on my ASUS A8N-SLI Premium system board.

I use the RAID to store partition backup image files which are split into
multiple 2GB segments. The backup segments total approx 70Gb.

Each week I copy the image files to a removable hard drive which usually
takes approx 25-30mins.

However today after selecting all the segments (77GB Total) and beginning
the copy,
Windows is estimating over 200 minutes for the copying!

I had similar trouble a few months ago so ran a disc check on the RAID
array
which took over 30hrs to complete! It seemed to fix whatever errors it
found as since then it ran normally taking approx 25-30mins to copy the
files.

However today the same lengthy copying problem has recurred.

Any idea what might cause this?

Right now I'm thinking I'll need to reformat the drives but I'll have to
buy
another 500GB drive to painstakingly copy all the data off the RAID array
first! Bummer!

Thanks for any info.

Ian

30 min for 77GB is about 42MB/s. That is pretty good. 200 min
is about 6MB/s. Quite slow. May be PIO instead of DMA
on a disk (bad cabeling), may be excessive fragmentation.
May also be bad sectors or other disk issues.

Do not replace the disks before you have have diagnised the
problem. At the moment it need not be the disks themselves.

Arno



Hi Arno

Thanks for replying.

Ive checked all the settings for the disk drives, SATA controller and RAID
controller in device manager as well as disc settings in disk management but
I cant see anywhere to check or alter the transfer mode to the RAID array.

I've downloaded and installed the lastest WD Data Lifeguard Tools but it
didnt report any problems and it seems pretty sparse in that it doesnt seem
to offer any diagnostic utilities.

Are there third party utilities I can run which can check the drives while
they are still part of the RAID?

I'm *slowly* moving stuff off the RAID - buring to DVD-R but its painfully
slow. Ive got an 18x DVD burner and with Verbatim discs I can usually burn
at 18x. But tonight Nero says.. "can only write at 4x because the speed of
the source data is too slow".

As if I didnt know!

Cheers

Ian

Previously 231 wrote:
Arno Wagner wrote:
Previously Ian R wrote:
Hi

I have a 500GB RAID1 array using brand new Western Digital drives
and the Sil 3114 chipset on my ASUS A8N-SLI Premium system board.

I use the RAID to store partition backup image files which are split
into multiple 2GB segments. The backup segments total approx 70Gb.

Each week I copy the image files to a removable hard drive which
usually takes approx 25-30mins.

However today after selecting all the segments (77GB Total) and
beginning the copy,
Windows is estimating over 200 minutes for the copying!

I had similar trouble a few months ago so ran a disc check on the
RAID array which took over 30hrs to complete! It seemed to fix
whatever errors it found as since then it ran normally taking approx
25-30mins to copy the files.

However today the same lengthy copying problem has recurred.

Any idea what might cause this?

Right now I'm thinking I'll need to reformat the drives but I'll
have to buy another 500GB drive to painstakingly copy all the data
off the RAID array first! Bummer!

30 min for 77GB is about 42MB/s. That is pretty good. 200 min
is about 6MB/s. Quite slow. May be PIO instead of DMA on a disk

Yes.

(bad cabeling),

Or something else turned the DMA off.

may be excessive fragmentation.

Nope, you wont get that dramatic a result from that.

Oh, yes. You can get even worse. I have seen it. Remember that
this is an average over 77GB.

May also be bad sectors or other disk issues.

Yep. And the best way to check for that is the SMART report,
after breaking the RAID array if necessary to do that.

Actually the way to do this is to attach the disks to a different
controller and never acess them in R/W mode. E.g. Knoppix
can help here.

Arno

Previously Ian R wrote:

"Arno Wagner" wrote in message
...
Previously Ian R wrote:
Hi

I have a 500GB RAID1 array using brand new Western Digital drives and the
Sil 3114 chipset on my ASUS A8N-SLI Premium system board.

I use the RAID to store partition backup image files which are split into
multiple 2GB segments. The backup segments total approx 70Gb.

Each week I copy the image files to a removable hard drive which usually
takes approx 25-30mins.

However today after selecting all the segments (77GB Total) and beginning
the copy,
Windows is estimating over 200 minutes for the copying!

I had similar trouble a few months ago so ran a disc check on the RAID
array
which took over 30hrs to complete! It seemed to fix whatever errors it
found as since then it ran normally taking approx 25-30mins to copy the
files.

However today the same lengthy copying problem has recurred.

Any idea what might cause this?

Right now I'm thinking I'll need to reformat the drives but I'll have to
buy
another 500GB drive to painstakingly copy all the data off the RAID array
first! Bummer!

Thanks for any info.

Ian

30 min for 77GB is about 42MB/s. That is pretty good. 200 min
is about 6MB/s. Quite slow. May be PIO instead of DMA
on a disk (bad cabeling), may be excessive fragmentation.
May also be bad sectors or other disk issues.

Do not replace the disks before you have have diagnised the
problem. At the moment it need not be the disks themselves.

Arno



Hi Arno

Thanks for replying.

Ive checked all the settings for the disk drives, SATA controller and RAID
controller in device manager as well as disc settings in disk management but
I cant see anywhere to check or alter the transfer mode to the RAID array.

I've downloaded and installed the lastest WD Data Lifeguard Tools but it
didnt report any problems and it seems pretty sparse in that it doesnt seem
to offer any diagnostic utilities.

Are there third party utilities I can run which can check the drives while
they are still part of the RAID?

You can remove both disks, attach each one to a different
controller and use a Knoppix CD only Linux to get their SMART
status, and in addition run a long SMART selftest. The tool for
this is smartctl. Knoppix mounts the disks readonly, so they will
form a valid RAID again, when connected back to the RAID controller.

I'm *slowly* moving stuff off the RAID - buring to DVD-R but its
painfully slow. Ive got an 18x DVD burner and with Verbatim discs I
can usually burn at 18x. But tonight Nero says.. "can only write at
4x because the speed of the source data is too slow".

As if I didnt know!

Hm. Maybe get a cheap external USB HDD and move everytginh there?
You could do this overnight and unattended.

Arno

Arno Wagner wrote:
Previously 231 wrote:
Arno Wagner wrote:
Previously Ian R wrote:
Hi

I have a 500GB RAID1 array using brand new Western Digital drives
and the Sil 3114 chipset on my ASUS A8N-SLI Premium system board.

I use the RAID to store partition backup image files which are
split into multiple 2GB segments. The backup segments total approx
70Gb.

Each week I copy the image files to a removable hard drive which
usually takes approx 25-30mins.

However today after selecting all the segments (77GB Total) and
beginning the copy,
Windows is estimating over 200 minutes for the copying!

I had similar trouble a few months ago so ran a disc check on the
RAID array which took over 30hrs to complete! It seemed to fix
whatever errors it found as since then it ran normally taking
approx 25-30mins to copy the files.

However today the same lengthy copying problem has recurred.

Any idea what might cause this?

Right now I'm thinking I'll need to reformat the drives but I'll
have to buy another 500GB drive to painstakingly copy all the data
off the RAID array first! Bummer!

30 min for 77GB is about 42MB/s. That is pretty good. 200 min
is about 6MB/s. Quite slow. May be PIO instead of DMA on a disk

Yes.

(bad cabeling),

Or something else turned the DMA off.

may be excessive fragmentation.

Nope, you wont get that dramatic a result from that.

Oh, yes.

Nope.

You can get even worse.

Nope.

I have seen it.

No you havent.

Remember that this is an average over 77GB.

You cant get a 7/1 reduction in thruput due to excessive fragmentation.

The size is irrelevant to that.

May also be bad sectors or other disk issues.

Yep. And the best way to check for that is the SMART report,
after breaking the RAID array if necessary to do that.

Actually the way to do this is to attach the disks to a
different controller and never acess them in R/W mode.

What I said in different words.

E.g. Knoppix can help here.

Previously 231 wrote:
Arno Wagner wrote:
Previously 231 wrote:
Arno Wagner wrote:
Previously Ian R wrote:
Hi

I have a 500GB RAID1 array using brand new Western Digital drives
and the Sil 3114 chipset on my ASUS A8N-SLI Premium system board.

I use the RAID to store partition backup image files which are
split into multiple 2GB segments. The backup segments total approx
70Gb.

Each week I copy the image files to a removable hard drive which
usually takes approx 25-30mins.

However today after selecting all the segments (77GB Total) and
beginning the copy,
Windows is estimating over 200 minutes for the copying!

I had similar trouble a few months ago so ran a disc check on the
RAID array which took over 30hrs to complete! It seemed to fix
whatever errors it found as since then it ran normally taking
approx 25-30mins to copy the files.

However today the same lengthy copying problem has recurred.

Any idea what might cause this?

Right now I'm thinking I'll need to reformat the drives but I'll
have to buy another 500GB drive to painstakingly copy all the data
off the RAID array first! Bummer!

30 min for 77GB is about 42MB/s. That is pretty good. 200 min
is about 6MB/s. Quite slow. May be PIO instead of DMA on a disk

Yes.

(bad cabeling),

Or something else turned the DMA off.

may be excessive fragmentation.

Nope, you wont get that dramatic a result from that.

Oh, yes.

Nope.

You can get even worse.

Nope.

I have seen it.

No you havent.

Remember that this is an average over 77GB.

You cant get a 7/1 reduction in thruput due to excessive fragmentation.

The size is irrelevant to that.

You have no clue what you are talking about, obviously. The worst
case, and it can be reached in practice, is one seek per cluster. If
we assume 16kB clusters and a 7200rpm disk with 10ms seek time and 4ms
average latency, that comes down to just over 1MB/s. That is without
any accesses for the management information and time to actually read
anything.

Arno

"Arno Wagner" wrote in message ...

may be excessive fragmentation.

Nope, you wont get that dramatic a result from that.

Oh, yes.

Nope.

You can get even worse.

Nope.

I have seen it.

No you havent.

Remember that this is an average over 77GB.

You cant get a 7/1 reduction in thruput due to excessive fragmentation.

The size is irrelevant to that.

You have no clue what you are talking about, obviously. The worst
case, and it can be reached in practice, is one seek per cluster. If
we assume 16kB clusters and a 7200rpm disk with 10ms seek time and 4ms
average latency, that comes down to just over 1MB/s. That is without
any accesses for the management information and time to actually read
anything.

You have no real world experience. Free clusters come in runs, not randomly scattered.

Arno Wagner wrote:
Previously 231 wrote:
Arno Wagner wrote:
Previously 231 wrote:
Arno Wagner wrote:
Previously Ian R wrote:
Hi

I have a 500GB RAID1 array using brand new Western Digital drives
and the Sil 3114 chipset on my ASUS A8N-SLI Premium system board.

I use the RAID to store partition backup image files which are
split into multiple 2GB segments. The backup segments total
approx 70Gb.

Each week I copy the image files to a removable hard drive which
usually takes approx 25-30mins.

However today after selecting all the segments (77GB Total) and
beginning the copy,
Windows is estimating over 200 minutes for the copying!

I had similar trouble a few months ago so ran a disc check on the
RAID array which took over 30hrs to complete! It seemed to fix
whatever errors it found as since then it ran normally taking
approx 25-30mins to copy the files.

However today the same lengthy copying problem has recurred.

Any idea what might cause this?

Right now I'm thinking I'll need to reformat the drives but I'll
have to buy another 500GB drive to painstakingly copy all the
data off the RAID array first! Bummer!

30 min for 77GB is about 42MB/s. That is pretty good. 200 min
is about 6MB/s. Quite slow. May be PIO instead of DMA on a disk

Yes.

(bad cabeling),

Or something else turned the DMA off.

may be excessive fragmentation.

Nope, you wont get that dramatic a result from that.

Oh, yes.

Nope.

You can get even worse.

Nope.

I have seen it.

No you havent.

Remember that this is an average over 77GB.

You cant get a 7/1 reduction in thruput due to excessive
fragmentation.

The size is irrelevant to that.

You have no clue what you are talking about, obviously.

We'll see...

The worst case, and it can be reached in practice, is one seek per cluster.

That never ever happens in practice.

If we assume 16kB clusters and a 7200rpm disk with 10ms seek
time and 4ms average latency, that comes down to just over 1MB/s.

Nope.

That is without any accesses for the management
information and time to actually read anything.

Wrong, as always.