Why is disk performance occasionally so slow?

Hi

I'm running XP Pro on an ASUS A8N-SLI with AMD X2 4200.

Every weekend I do a full backup.

For speed, I create the first backup to an internal Samsung 1TB F1 drive -
one of the current fastest drives.

I then copy the backup files to an internal mirrored RAID SATA drive.

I then make another copy to other SATA drives which are in a removable tray
for off site storage.

Most often the backup occurs at around 3Gb/minute and takes approx 30
minutes to write and approx 25 mins to verify.

But occasionally the drive performance plummets. With the backup taking
over an hour to create (at approx 1GB/minute) and even longer to verify.

When it goes slow I've checked task manager and nothing else is hogging the
system.

I've tried changing which drive I write the first backup to or copy from and
it makes no difference. So it doesn't seem to be one particular drive that
may be dodgy.

I've run my backup at various times and inexplicably the speed is fine again
and then sometimes slow.

Any ideas what might cause this, what I should check?

Thanks for your time.

Ian

I've run my backup at various times and inexplicably the speed is fine
again
and then sometimes slow.

Any ideas what might cause this, what I should check?

Well I run 2 backup systems, True Image for the system drive,
FilebackPC for the data drive, both in differential mode which
means only changed files/ items are backed up.
The backup drive is eSATA off the header next to the
system drive, SATA2.
As to slowness, there are some XP services, like
indexing that hog resources, and some AV's like Kaspersky
like to inspect everything.
To diagnose run Win Task Manager and see whether
the slowness is due to processor load (processor bound)
or all the memory (chip, RAM, swap file) is in use
(memory bound and pagefaulting)..
Once you know what taking all the resources, and slowing
things down, you are on the way to cracking the problem.
With my system if Kaspersky (retail licenced) is doing a
full system scan, verything else seems to stop (run like
treacle) which is something I'm digging into.
KAV is supposed to be adaptive.

On Mon, 11 May 2009 10:21:14 -0000, "Ian R"
wrote:

Hi

I'm running XP Pro on an ASUS A8N-SLI with AMD X2 4200.

Every weekend I do a full backup.
1. What program do you use to do the "backup" and what command(s)
are used?
2. What program do you use to do the "copy" and what command(s) are
used?
3. What program do you use to do the "verify" and what command(s)
are used?

4. Are you using the disk controller to make the copy or backup,
perhaps by adding another copy to a RAID set? Note that
mirroring, etc., need not be limited to 2 copies or you might remove
a copy from a mirror and then mirror both of the separated clones.
5. Have you looked at the SMART data for all of the drives involved?

I can't tell if you, for instance, use a backup program to make
a single (or small number) of container files or if you do a
"clone" operation that keeps the individual files separate.

Also, if you are making a container file, I can't tell if the slowdown
happens in the part that makes the container file (which might require
a lock for each individual file) or in a copy operation for the
container file.

Also: is it possible that the files are in use (and perhaps locked)
or the disk is busy with other operations while the first backup is
done?


For speed, I create the first backup to an internal Samsung 1TB F1 drive -
one of the current fastest drives.

I then copy the backup files to an internal mirrored RAID SATA drive.


I then make another copy to other SATA drives which are in a removable tray
for off site storage.

Most often the backup occurs at around 3Gb/minute and takes approx 30
minutes to write and approx 25 mins to verify.

But occasionally the drive performance plummets. With the backup taking
over an hour to create (at approx 1GB/minute) and even longer to verify.

When it goes slow I've checked task manager and nothing else is hogging the
system.

I've tried changing which drive I write the first backup to or copy from and
it makes no difference. So it doesn't seem to be one particular drive that
may be dodgy.

I've run my backup at various times and inexplicably the speed is fine again
and then sometimes slow.

Any ideas what might cause this, what I should check?

Thanks for your time.

Ian

"Mark F" wrote in message
news
On Mon, 11 May 2009 10:21:14 -0000, "Ian R"
wrote:

Hi

I'm running XP Pro on an ASUS A8N-SLI with AMD X2 4200.

Every weekend I do a full backup.
1. What program do you use to do the "backup" and what command(s)
are used?
2. What program do you use to do the "copy" and what command(s) are
used?
3. What program do you use to do the "verify" and what command(s)
are used?

4. Are you using the disk controller to make the copy or backup,
perhaps by adding another copy to a RAID set? Note that
mirroring, etc., need not be limited to 2 copies or you might remove
a copy from a mirror and then mirror both of the separated clones.
5. Have you looked at the SMART data for all of the drives involved?

I can't tell if you, for instance, use a backup program to make
a single (or small number) of container files or if you do a
"clone" operation that keeps the individual files separate.

Also, if you are making a container file, I can't tell if the slowdown
happens in the part that makes the container file (which might require
a lock for each individual file) or in a copy operation for the
container file.

Also: is it possible that the files are in use (and perhaps locked)
or the disk is busy with other operations while the first backup is
done?



Hi Mark

Thanks for replying.

Most often I use DriveSnapshot disk imaging.

I'm also experimenting with Acronis True Image.

It doesnt matter which one I use, when the disk performance is slow, its
slow with either one.

I always make sure that none of the files being backed up are open.

Ive got SMART monitoring enabled in the BIOS for all my drives and Ive never
had any notifications of problems.

Ive used Everest to view the SMART data and it hasnt reported any problems.

Is there another tool that will allow me to see the Smart data?

Ian

"Ato_Zee" wrote in message
...

I've run my backup at various times and inexplicably the speed is fine
again
and then sometimes slow.

Any ideas what might cause this, what I should check?

Well I run 2 backup systems, True Image for the system drive,
FilebackPC for the data drive, both in differential mode which
means only changed files/ items are backed up.
The backup drive is eSATA off the header next to the
system drive, SATA2.
As to slowness, there are some XP services, like
indexing that hog resources, and some AV's like Kaspersky
like to inspect everything.
To diagnose run Win Task Manager and see whether
the slowness is due to processor load (processor bound)
or all the memory (chip, RAM, swap file) is in use
(memory bound and pagefaulting)..
Once you know what taking all the resources, and slowing
things down, you are on the way to cracking the problem.
With my system if Kaspersky (retail licenced) is doing a
full system scan, verything else seems to stop (run like
treacle) which is something I'm digging into.
KAV is supposed to be adaptive.

Hi Ato_Zee

Thanks for replying.

You might have missed that I wrote...

When it goes slow I've checked task manager and nothing else is hogging
the system.

Cheers

Ian

Ian R wrote:
"Ato_Zee" wrote in message
...
I've run my backup at various times and inexplicably the speed is fine
again
and then sometimes slow.

Any ideas what might cause this, what I should check?
Well I run 2 backup systems, True Image for the system drive,
FilebackPC for the data drive, both in differential mode which
means only changed files/ items are backed up.
The backup drive is eSATA off the header next to the
system drive, SATA2.
As to slowness, there are some XP services, like
indexing that hog resources, and some AV's like Kaspersky
like to inspect everything.
To diagnose run Win Task Manager and see whether
the slowness is due to processor load (processor bound)
or all the memory (chip, RAM, swap file) is in use
(memory bound and pagefaulting)..
Once you know what taking all the resources, and slowing
things down, you are on the way to cracking the problem.
With my system if Kaspersky (retail licenced) is doing a
full system scan, verything else seems to stop (run like
treacle) which is something I'm digging into.
KAV is supposed to be adaptive.

Hi Ato_Zee

Thanks for replying.

You might have missed that I wrote...

When it goes slow I've checked task manager and nothing else is hogging
the system.


Task manager only shows you what is hogging the cpu - not what is
hogging the IO resources. While you are doing your copying, everything
else on the system will run like treacle (Windows does not prioritise IO
or memory properly), yet task manager will continue to show very little
cpu use. Junk like antivirus software and windows indexing, or
background defrag utilities, will all be IO (and possibly memory) bound,
not processor limited.

Your problem might lie elsewhere, of course - just don't dismiss these
causes so easily. In task manager, you can view other columns such as
page faults, memory uses, and IO requests - that might give you some clues.

Ian R wrote:
"Mark F" wrote in message
news
On Mon, 11 May 2009 10:21:14 -0000, "Ian R"
wrote:

Hi

I'm running XP Pro on an ASUS A8N-SLI with AMD X2 4200.

Every weekend I do a full backup.
1. What program do you use to do the "backup" and what command(s)
are used?
2. What program do you use to do the "copy" and what command(s) are
used?
3. What program do you use to do the "verify" and what command(s)
are used?

4. Are you using the disk controller to make the copy or backup,
perhaps by adding another copy to a RAID set? Note that
mirroring, etc., need not be limited to 2 copies or you might remove
a copy from a mirror and then mirror both of the separated clones.
5. Have you looked at the SMART data for all of the drives involved?

I can't tell if you, for instance, use a backup program to make
a single (or small number) of container files or if you do a
"clone" operation that keeps the individual files separate.

Also, if you are making a container file, I can't tell if the
slowdown happens in the part that makes the container file (which
might require a lock for each individual file) or in a copy
operation for the container file.

Also: is it possible that the files are in use (and perhaps locked)
or the disk is busy with other operations while the first backup is
done?



Hi Mark

Thanks for replying.

Most often I use DriveSnapshot disk imaging.

I'm also experimenting with Acronis True Image.

It doesnt matter which one I use, when the disk performance is slow,
its slow with either one.

I always make sure that none of the files being backed up are open.

Ive got SMART monitoring enabled in the BIOS for all my drives and
Ive never had any notifications of problems.

Ive used Everest to view the SMART data and it hasnt reported any problems.

What matters is the data, not the OKs etc.

Is there another tool that will allow me to see the Smart data?

Everest is fine. Capture it when its slow and post it here.

For clarity, you should include the exact commands that you use.

I suggest that you should run while monitoring various things.

You might:
. Use start Programs Administrative Tools Performance
and monitor the read and write data rate and operation rate
on the disks being used. If this doesn't show anything strange
there are many other activities you can choose to monitor.
Look for low read rate or low write rate and high CPU use.

. Use a system monitoring program to see what is going on.

I use Iarsn TaskInfo from www.iarsn.com. This allows me to
see the instantaneous and average values for many variables, but
not the individual disk rates.

On Tue, 12 May 2009 01:32:19 -0000, "Ian R"
wrote:


"Mark F" wrote in message
news
On Mon, 11 May 2009 10:21:14 -0000, "Ian R"
wrote:

Hi

I'm running XP Pro on an ASUS A8N-SLI with AMD X2 4200.

Every weekend I do a full backup.
1. What program do you use to do the "backup" and what command(s)
are used?
2. What program do you use to do the "copy" and what command(s) are
used?
3. What program do you use to do the "verify" and what command(s)
are used?

4. Are you using the disk controller to make the copy or backup,
perhaps by adding another copy to a RAID set? Note that
mirroring, etc., need not be limited to 2 copies or you might remove
a copy from a mirror and then mirror both of the separated clones.
5. Have you looked at the SMART data for all of the drives involved?

I can't tell if you, for instance, use a backup program to make
a single (or small number) of container files or if you do a
"clone" operation that keeps the individual files separate.

Also, if you are making a container file, I can't tell if the slowdown
happens in the part that makes the container file (which might require
a lock for each individual file) or in a copy operation for the
container file.

Also: is it possible that the files are in use (and perhaps locked)
or the disk is busy with other operations while the first backup is
done?



Hi Mark

Thanks for replying.

Most often I use DriveSnapshot disk imaging.

I'm also experimenting with Acronis True Image.

It doesnt matter which one I use, when the disk performance is slow, its
slow with either one.

I always make sure that none of the files being backed up are open.

Ive got SMART monitoring enabled in the BIOS for all my drives and Ive never
had any notifications of problems.

Ive used Everest to view the SMART data and it hasnt reported any problems.

Is there another tool that will allow me to see the Smart data?

Ian

David Brown wrote:
Task manager only shows you what is hogging the cpu - not what is
hogging the IO resources. While you are doing your copying, everything
else on the system will run like treacle (Windows does not prioritise IO
or memory properly), yet task manager will continue to show very little
cpu use. Junk like antivirus software and windows indexing, or
background defrag utilities, will all be IO (and possibly memory) bound,
not processor limited.


I often see i/o operations being listed as "kernel time" in the Task
Manager performance graph. You do have to turn on the option to "show
kernel times" in Taskman, though. This is basically like Unix's system
vs. user times.

Yousuf Khan

Ian R wrote:
It doesnt matter which one I use, when the disk performance is slow, its
slow with either one.

I always make sure that none of the files being backed up are open.

Ive got SMART monitoring enabled in the BIOS for all my drives and Ive never
had any notifications of problems.

Ive used Everest to view the SMART data and it hasnt reported any problems.

Is there another tool that will allow me to see the Smart data?


Yes, there is another tool, much better than Everest for these purposes,
called Hard Disk Sentinel (hdsentinel.com). It's shareware, but I
believe even the unregistered version will show you disk performance
graphs. It installs itself at Windows' boot-up and monitors all your
drives through SMART, even external ones on USB or Firewire or eSATA. It
might even log transient SMART errors as they occur. But even if it
doesn't have access to SMART data on that drive, it will still be able
to measure throughput on it. It'll show a separate graph for disk
utilization and for transfer rates. Between the two maybe a clue will
present itself.

Yousuf Khan