[9fans] Changing disks on fs64 server

[9fans] Changing disks on fs64 server

[g.pavelcak]

I updated my kernel and copydev appears to be working. Just one question. Is it surprising that this type of copy is really slow? It said it was going to copy 6 million plus blocks. It's now (8:20 AM Eastern) done just over 5 million blocks. I started about 1:30 PM yesterday. Does that mean I have really slow disks or is that normal? I'm copying from IDE to a mirrored scsi device: copydev h0 {w2w3}, as Geoff suggested.

Thanks.

Greg

Re: [9fans] Changing disks on fs64 server

[geoff]

Copydev copies using the file server's block size; if it's 4K or
greater, the copy should be relatively quick.  It should also report
progress so you can gauge how long it will take.

It's possible that you don't have a bus-mastering IDE controller.
Even if your disks are capable of DMA, the file server will end up
doing programmed I/O, which is much slower.  Look for this message in
your file server console log:

	h0: disabling dma: not on a busmastering controller

Also check that you haven't set conf.idedma to 0, like this:

fs/9fsfs.c:		conf.idedma = 0; /* for old machines */

If conf.idedma is non-zero, you should see ` and IDE DMA+RWM' in your
file server log:

	Plan 9 63-bit file server with 4-deep indir blks and IDE DMA+RWM

Re: [9fans] Changing disks on fs64 server

[geoff]

copydev appeared in my source tree in Feb 2005 but I'm not sure when
it appeared on sources, and network connectivity from here to Murray
Hill is poor today.

	copydev {h0h2} {w2w3}
should work.  If you've had no I/O errors on h0,
	copydev h0 {w2w3}
would work too.

Re: [9fans] Changing disks on fs64 server

[Gregory Pavelcak]

I have current sources.  Even grepped around a bit for copydev but
missed it.  Version shows Dec 5 2005.  Is copydev new, or did I
somehow do something wrong when I built my existing kernel?  Do I just
re-follow the instructions for making the file server boot floppy?  If
so, is something like `copydev {h0h2} {w2w3}' OK? As of now, both
devices are there: the IDE disks on the original config and I added
the new scsi disks on their own filsys and named it `output' in case I
need to use copyworm.

Thanks.

Greg

Re: [9fans] Changing disks on fs64 server

[geoff]

copydev exists; see port/config.c.  Is your /sys/src/fs current?

[9fans] Changing disks on fs64 server

[g.pavelcak]

I thought I was having an IDE disk failure, now I'm not so sure, but
I'm committed now to changing my file server config. Basically I want
to go from:

                c[w0w1]f{h0h2}

to
                c[w0w1]f{w2w3}

and I would like to preserve the history that's been recorded. I had
intended to use copydev. I forget the error message, but it appears
not to be there. Can I do this? How?

Thanks.

Greg