IFD/IFL File Compression

[jack450]

When I do a backup, my number one consideration is reliability. I wouldn't mind smaller files and faster backup times, but never at the expense of reliability. For that reason I always choose "NONE" for compression. However, I have noticed that the new "Enhanced Speed A" cuts the backup time in half. That's a pretty desirable result if the backup is just as reliable as one without compression. So I guess the question is this: Anyone have any reliability issues when restoring a backup made using the "Enhanced Speed A" compression scheme?

Jack G.

[Brian K]

Jack,

Quick answer. No.

[jack450]

Thanks, Brian. I went ahead and did a backup on 140 gig of data with Image for DOS v. 2.74, with the byte for byte validation and the enhanced speed A compression. It took a little less than two hours to backup, but it took over six hours to validate. I was using a Western Digital My Book with a USB connection. In watching the data ticker during validation, there was a constant stop and go. I'm wondering if that had anythiong to do with the compression because I don't recall this stop and go issue when the backup has no compression. Any thoughts?

[DrTeeth]

On Fri, 14 Sep 2012 10:47:35 PDT, just as I was about to take a herb,
jack450 disturbed my reverie and wrote:

>Thanks, Brian. I went ahead and did a backup on 140 gig of data with Image for DOS v. 2.74, with the byte for byte validation and the enhanced speed A compression. It took a little less than two hours to backup, but it took over six hours to validate. I was using a Western Digital My Book with a USB connection. In watching the data ticker during validation, there was a constant stop and go. I'm wondering if that had anythiong to do with the compression because I don't recall this stop and go issue when the backup has no compression. Any thoughts?
>
That does not sound right at all. I use the same settings and to not
have that difference in performance. I backup to an internal hard
drive and then mirror that folder to an external USB 3 drive.
--

Cheers

DrT
______________________________
We may not be able to prevent the stormy times in
our lives; but we can always choose whether or not
to dance in the puddles (Jewish proverb).

[jack450]

DrTeeth wrote:
> On Fri, 14 Sep 2012 10:47:35 PDT, just as I was about to take a herb,
> jack450 disturbed my reverie and wrote:
>
> ... It took a little less than two hours to backup, but
> it took over six hours to validate. I was using a Western Digital My Book
> with a USB connection. In watching the data ticker during validation,
> there was a constant stop and go.
> >


> That does not sound right at all. I use the same settings and to not
> have that difference in performance. I backup to an internal hard
> drive and then mirror that folder to an external USB 3 drive.
> --
>
> Cheers
>
> DrT

I agree that something is not right, but what? I notice that you're using a USB 3 connection which is quite a bit faster than my USB 2 connection, but that's not the problem here. The stop and go during the validation caused the lengthy validation time -- I just don't know what caused the stop and go issue.

I repeated the entire backup and validate byte for byte with a different external drive that has additional interfaces. I used a firewire interface and Image for Linux 2.74 with NO compression. The entire process completed in 4 hours and 25 minutes.

So -- firewire instead of USB, Image for Linux instead of Image for Dos, and no compression instead of enhanced speed A compression. The result: half the time or twice as fast. I don't know where the difference is, but I suspect it's the USB. There should be no reason that IFD and IFL should return radically different times, and it makes no sense that a compressed file, which is smaller, should take longer to verify.

[TAC109]

On Fri, 14 Sep 2012 16:40:09 PDT, jack450 wrote:

>DrTeeth wrote:
>> On Fri, 14 Sep 2012 10:47:35 PDT, just as I was about to take a herb,
>> jack450 disturbed my reverie and wrote:
>>
>> ... It took a little less than two hours to backup, but
>> it took over six hours to validate. I was using a Western Digital My Book
>> with a USB connection. In watching the data ticker during validation,
>> there was a constant stop and go.
>> >
>
>
>> That does not sound right at all. I use the same settings and to not
>> have that difference in performance. I backup to an internal hard
>> drive and then mirror that folder to an external USB 3 drive.
>> --
>>
>> Cheers
>>
>> DrT
>
>I agree that something is not right, but what? I notice that you're using a USB 3 connection which is quite a bit faster than my USB 2 connection, but that's not the problem here. The stop and go during the validation caused the lengthy validation time -- I just don't know what caused the stop and go issue.
>
>I repeated the entire backup and validate byte for byte with a different external drive that has additional interfaces. I used a firewire interface and Image for Linux 2.74 with NO compression. The entire process completed in 4 hours and 25 minutes.
>
>So -- firewire instead of USB, Image for Linux instead of Image for Dos, and no compression instead of enhanced speed A compression. The result: half the time or twice as fast. I don't know where the difference is, but I suspect it's the USB. There should be no reason that IFD and IFL should return radically different times, and it makes no sense that a compressed file, which is smaller, should take longer to verify.
>
You have changed too many variables at once!

My experience with backing up to USB 2 drives is that reading back
(simple verifying) is faster than writing (ratio of roughly 2:3). This
is with the removable drive properties in Windows set to optimise for
quick removal.

[TeraByte Support]

If your using USB2 and the "USB" option in the app, enable the various fix
usb hang options when creating the boot disk.

"jack450" wrote in message news:3196@public.image...

Thanks, Brian. I went ahead and did a backup on 140 gig of data with Image
for DOS v. 2.74, with the byte for byte validation and the enhanced speed A
compression. It took a little less than two hours to backup, but it took
over six hours to validate. I was using a Western Digital My Book with a USB
connection. In watching the data ticker during validation, there was a
constant stop and go. I'm wondering if that had anythiong to do with the
compression because I don't recall this stop and go issue when the backup
has no compression. Any thoughts?

[DrTeeth]

On Fri, 14 Sep 2012 16:40:09 PDT, just as I was about to take a herb,
jack450 disturbed my reverie and wrote:

>There should be no reason that IFD and IFL should return radically different times

Actually, there is. IfD uses the BIOS and IfL does not. Your BIOS may
be the limiting factor. How fragmented is your source drive?
--

Cheers

DrT
______________________________
We may not be able to prevent the stormy times in
our lives; but we can always choose whether or not
to dance in the puddles (Jewish proverb).

[jack450]

I appreciate all the comments. I'm pretty satisfied with the results I get from IFL. A full disk backup of 140 gig of data in 4 hours with a byte for byte validation and no compression is acceptable to me. The restore of the image took 59 minutes, which is also quite good.

I intentionally do not use Image for Windows because of the potential issues Windows can introduce. For years I used a program that originally ran under DOS and I never had a single problem. When newer versions came out, the program was no longer DOS based and had to run under Windows. One had to upgrade to the newer versions to to keep up with the newer devices that computers use these days. It worked well more often than not, but when something didn't, you could spend half a day trying to figure out what went wrong. Backing up a hard drive is a necessary task and not something I look forward to doing, or something that I take great pride in being able to accomplish. I prefer programs that are reliable and as "idiot proof" as possible. I love the simplicity of IFD and IFL.

Jack

[AlanD]

On 2012-09-15 1:49 PM, jack450 wrote:
> I appreciate all the comments. I'm pretty satisfied with the results I get from IFL. A full disk backup of 140 gig of data in 4 hours with a byte for byte validation and no compression is acceptable to me. The restore of the image took 59 minutes, which is also quite good.
>
> I intentionally do not use Image for Windows because of the potential issues Windows can introduce. For years I used a program that originally ran under DOS and I never had a single problem. When newer versions came out, the program was no longer DOS based and had to run under Windows. One had to upgrade to the newer versions to to keep up with the newer devices that computers use these days. It worked well more often than not, but when something didn't, you could spend half a day trying to figure out what went wrong. Backing up a hard drive is a necessary task and not something I look forward to doing, or something that I take great pride in being able to accomplish. I prefer programs that are reliable and as "idiot proof" as possible. I love the simplicity of IFD and IFL.
>
> Jack
>
>
for comparison only: I backup a drive with 40% of the data that you
have to a second internal hard drive. I am using IFW, and byte-for-byte
validation (enhanced speed A) . There are three partitions to backup and
validate (as one hard drive).
It takes me 12% of the time that you show (28-29 min)

AlanD