USB hubs

[Heidi Gear]

Greetings!

New here and just about to start archiving my CD collection... so here's my first
question! (I've done a quick search and I don't think it's been covered - apologies
if it has). I'd be grateful if anyone can help with some advice.

I plan to make multiple copies simultaneously from a single rip, so the set up will be
(in loose terms) laptop connected to external hard drives (two) via USB and a USB
hub, with extra copy going to hard drive of laptop for burning onto DVD data disc.
(Phew! it's a lot of work this stuff isn't it?).

The aim is to make absolutely the highest quality copy that I can, and it occurs to
me that maybe having the data passing through a (cheap) usb hub is maybe not
such a good idea.

What do other folks do?

Or to frame the question in a more general way... once the CD contents have been
extracted and converted to, say, FLAC - does it matter how this "data" is then subsequently
moved around, eg via usb to external hard drive?? (I appreciate that burning the data
to another disc will bring it's own set of issues, I'm just talking about "direct" copying).
Is the process of transfer from one drive to another always a lossless process??

Many thanks,
HG

[garym]

Re: USB hubs

Or to frame the question in a more general way... once the CD contents have been
extracted and converted to, say, FLAC - does it matter how this "data" is then subsequently
moved around, eg via usb to external hard drive?? (I appreciate that burning the data
to another disc will bring it's own set of issues, I'm just talking about "direct" copying).
Is the process of transfer from one drive to another always a lossless process??

No, it doesn't matter. Otherwise the internet wouldn't work, your local network wouldn't work, and we wouldn't even be able to read your post (as it would have been jumbled when the 1s and 0s passed through hundreds of switches and paths to eventually show up on my computer.....

edit: and of course, there can always be errors in copying, moving, etc. but most modern operating systems (windows for example) will actually tell you when there is an error in copying or moving files. I've copied hundreds of thousands of audio files to any number of USB drives, computers over a local network, one USB drive to another, and even many files over the internet from one location to another. In all this copying I've never had an error show up other than an error that immediately made itself known (and was reported in an unmistakeable way to me as the user doing the copying).

[Porcus]

Re: USB hubs

I plan to make multiple copies simultaneously from a single rip, so the set up will be
(in loose terms) laptop connected to external hard drives (two) via USB and a USB
hub, with extra copy going to hard drive of laptop for burning onto DVD data disc.
(Phew! it's a lot of work this stuff isn't it?).

Do you intend to make different formats (say, one archive in lossless and one hard drive (or portable player) with, say, .mp3)? If so, use Multi Encoder.

If you want multiple backups, then I would rather copy en bloc afterwards. Or overnight.

The aim is to make absolutely the highest quality copy that I can, and it occurs to
me that maybe having the data passing through a (cheap) usb hub is maybe not
such a good idea.

General rule (exceptions below): copying works or it doesn't -- there is no 'gradual degradation'. No need for an expensive hub.

But:
- it may be slow. Especially if you went to eBay buying a hub that doesn't really support 2.0. (Some hubs actually don't, despite claiming so.)
- you may get time stamp issues. If you need to have complete control over what files are newer (for example for incremental backup purposes) then you might have to test a bit. Not due to the cheapness of your USB hub though.


What I would do:
- do the ripping. Or at least, do a day of ripping to C:\nowripping . That gives you time to do the re-ripping you need for e.g. scratched CDs too.
- at the end of the day, change name from 'nowripping' to 'yesterday'. Set up a cp job copying c:\yesterday to d:\yesterday and then d:\yesterday to e:\yesterday.
- morning after, use a copy verification tool (I use the XXCOPY freeware with the /CDU switch, which bitcompares every file) or an audio comparator (I use foobar2000 which bit-compares audio ... if the audio is identical, then the file copy was OK) and compare c:\yesterday to e:\yesterday. If they are equal, then they are equal to d:\yesterday too.
- when the copy job is verified, committ to your archive by moving the subfolders of driveletter:\yesterday to driveletter:\music , all three driveletters.

If you don't care about disc fragmentation you can use XXCOPY to do the initial copying too.

[Heidi Gear]

Re: USB hubs

Thanks for your answers, that's just what I wanted to know.

Hi Porcus - actually I was slightly confused: I had been reading about the multi encoder, but what I'm really going to
be doing is making multiple back ups in the same format (flac or wav).
Your methodology definitely looks like the way for me to go!

Hmmm... disc fragmentation? I do want to avoid that, in case it ever becomes a question of playback directly from these
hard drives.

So that's a good question: how is fragmentation avoided?
I envisaged just adding files incrementally to drives until they're full. EG, nothing like drive synchronisation or more usual
back up methods. As per your methodology, after a ripping session I will just have a big lump of additional files to be
added to a given drive.

I only understand these concepts in a vague way, but common sense seems to suggest the above would not give rise
to any fragmentation. Then again, since I'm an audio freak, common sense went out the window a long time ago!

Thanks again to both of you.

[Porcus]

Re: USB hubs

Hmmm... disc fragmentation? I do want to avoid that, in case it ever becomes a question of playback directly from these
hard drives.

So that's a good question: how is fragmentation avoided?

I actually do not know whether fragmentation is any issue whatsoever for audio playback, as it isn't much throughput. I mean, you copy a terabyte overnight, and that's half a year of playback. (Effective time, 24/7!) This isn't HD video ...

So ... on second thought, you shouldn't worry. Well maybe if your drives are making mechanical noises when searching.

Now to actually answer your last question: Windows' copy (or drag + drop) writes from start to end, and doesn't defragment upon write. Other utilities do not. XXCOPY will write and verify block-by-block I think, and fragments files. And I think encoding usually will. (Now the fact that Windows doesn't defragment when writing, is a double-edged sword: that means that if a file expands only slightly, it will have to be fragmented, and that does happen with your system files. More intelligent file managements spread out randomly. But I digress.)