[ale] Disk IO Question

[Greg Freemyer]

Can you comment on / answer the rest of my post?

> 60 GB per hour may or may not be slow.  If the files are very small, I
> find 100K files / hr to be a limiting factor in some cases.
>
So how many files per hour are you currently seeing?

> I also do a lot of "dd if=/dev/sdb of=/dev/sdc bs=4k
> conv=noerror,sync" copying of filesystems.  I see speeds of 250GB/hr
> even with just drive to drive transfers.  You raid array should be
> much faster.

Even as a test can try this?  If you don't unmap the source array, the
dest will not be a good copy, but this would still be a good
performance test.

> So if you can unmount your primary drive every night, you should be
> able to make a dd copy every night.  I have one vendor that is telling
> me they are moving data around at 1TB/hr.  (I'm not sure how true that
> is.)

If unmounting every night is a problem, consider LVM snapshots?  They
allow you to make a "point-in-time" copy that requires hours to
actually make.

Greg