Re: Using dd to Make a Clone of a Drive
I have used dump/restore and dd as well. For a block size, I chose 102400 which was the fastest -- but still slow compared to dump/restore. Dump/restore is not limited to making a whole image, blanks and all like dd. Once upon a time, I used this as the best: dd if=/dev/ad0 of=/dev/ad1 bs=102400 The obvious intention is to minimize the number of transfers, so theoretically the larger the transfer, the better. The maximum I/O transfer size is limited to the value of MAXPHYS, which is defined in sys/param.h: #ifndef MAXPHYS #define MAXPHYS(128 * 1024)/* max raw I/O transfer size */ #endif The ATA subsystem uses this value. SCSI drives were limited to 60 kB transfers, though this could have changed. I don't currently have any machine with SCSI disks connected, so I can't confirm that. A way to find is to run a command like will show the I/O: #dd if=/dev/ad0c of=/dev/null bs=128k & and in the background do an 'iostat ad0 1'. Here's an example with an IDE drive: #iostat ad0 1 tty ad0 cpu tin tout KB/t tps MB/s us ni sy in id 03 5.19 7 0.03 11 0 4 1 84 0 126 127.36 183 22.74 0 0 6 2 92 0 44 128.00 190 23.76 0 0 2 0 98 0 44 128.00 191 23.89 0 0 5 0 95 0 44 128.00 191 23.88 0 0 7 1 92 As you can see, it's really doing 128 kB transfers, for an average transfer rate of almost 24 MB/s. = I do all of my backups every night by scripts by using dump/restore to a dedicated separate HD. It is bootable and ready to go in case of a problem with my master HD. Just shutdown, switch HDs and reboot -- voila! Back on line within a minute and the data is always only a few hours old at the most. Once you master dump/restore, it is indispensable for handling file systems. Best regards, Jack _ FREE pop-up blocking with the new MSN Toolbar get it now! http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/ ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
On 2006-02-14 07:47, Kevin Kinsey <[EMAIL PROTECTED]> wrote: >Kevin Kinsey wrote: >>Giorgos Keramidas wrote: >>> Bah! That's too slow for my taste. I would usually go for a newfs, >>> dump, and restore option. For instance, to create a copy of /usr on a >>> second disk: >>> >>>newfs -U /dev/ad1s1a >>>mount /dev/ad1s1a /mnt >>>dump -0 -a -L /usr | ( cd /mnt ; restore ruvf - ) >>> >>> Copying with dd(1) is not as fast :) >> >> Sorry to butt in --- but I'm needing to start cloning too. Looks >> like a winner to me ... wouldn't this have the added advantage >> of making "same size and geometry" (cf. Erik Trulsson, 4 hours ago, >> this thread) less relevant? >> >> As long as the "new" slice had enough space, geometry shouldn't >> matter to dump|restore > > Just for the archives: > > Giorgios' solution is very nice, but needs the "-f" option and another > "-" to work properly AFAICT, both from experience and from reading > dump(8): > > dump -0 -a -L -f - /usr | (cd /mnt ; restore ruvf - ) > > If you don't include "-f" (for "file") and "-" (for "stdout"), then your > command will fail with: > > DUMP: Cannot open output "/dev/sa0" Oops! Yes, good catch :) ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
Kevin Kinsey wrote: Giorgos Keramidas wrote: On 2006-02-09 14:36, Martin McCormick <[EMAIL PROTECTED]> wrote: After installing FreeBSD5.4, the ISC dhcp server and ISC bind on a hard drive, I wanted to clone that drive to a second drive so as to generate a second server, using what I had already installed as a template. I used the following command: dd if=/dev/da0 of=/dev/da1 bs=512 It turns out that dd defaults to 512-byte blocks so I didn't really need the bs=512, but I am not sure I haven't made some other type of mistake. The dd command has been running for about 4 hours on a very fast system, with a 1-gig processor, 1 gig of RAM and two 31-GB drives. One would think it should have finished by now, but it is still running. Is this a valid method of copying the entire contents of one drive to another? Thank you. Bah! That's too slow for my taste. I would usually go for a newfs, dump, and restore option. For instance, to create a copy of /usr on a second disk: newfs -U /dev/ad1s1a mount /dev/ad1s1a /mnt dump -0 -a -L /usr | ( cd /mnt ; restore ruvf - ) Copying with dd(1) is not as fast :) Sorry to butt in --- but I'm needing to start cloning too. Looks like a winner to me ... wouldn't this have the added advantage of making "same size and geometry" (cf. Erik Trulsson, 4 hours ago, this thread) less relevant? As long as the "new" slice had enough space, geometry shouldn't matter to dump|restore Kevin Kinsey Just for the archives: Giorgios' solution is very nice, but needs the "-f" option and another "-" to work properly AFAICT, both from experience and from reading dump(8): dump -0 -a -L -f - /usr | (cd /mnt ; restore ruvf - ) If you don't include "-f" (for "file") and "-" (for "stdout"), then your command will fail with: DUMP: Cannot open output "/dev/sa0" unless you actually have a tape drive, as, of course, any experienced user could have told you would happen, if not when they read the incorrect command line, then when they saw, previously: DUMP: Dumping snapshot of /dev/$somedisk to /dev/sa0 I used the strategy above to clone a working installation of Wine and a rather obscure Win32 program from a 20 GB IDE HDD to an 8GB drive with good success after attempts to "re-create" a similar installation manually had failed, presumably because something in re: Wine had changed in the interim, though we've been unable to establish this as fact. So, I've adopted dump(8) and restore(8) for disk cloning as a result of this experience. Next step: moving to dump|restore for my home-brew backup routines HTH Someone, Kevin Kinsey -- Heisenberg may have slept here ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
On Feb 10, 2006, at 11:11 AM, Peter wrote: --- Bart Silverstrim <[EMAIL PROTECTED]> wrote: On Feb 10, 2006, at 9:50 AM, Giorgos Keramidas wrote: On 2006-02-10 09:44, Peter <[EMAIL PROTECTED]> wrote: --- Giorgos Keramidas <[EMAIL PROTECTED]> wrote: As long as the "new" slice had enough space, geometry shouldn't matter to dump|restore Right :) It also allows restoring in a different partition layout. Any chance of there being a way like this to restore to windows systems from the FreeBSD box? Not really. I'm far from being a Windows expert though, so YMMV. As an image? Look up partimage and partimaged. We've had some luck restoring from both a Linux system running the Partimaged daemon and booting from a Linux disk and restoring images off a samba/Windows share using partimage. I intend to use g4u. I have done some preliminary testing and I am quite confident that I can upload and download an image. I am now wondering about the situation where I need to recreate the partition that is to contain the image. It needs to be exactly the same size (sectors) as the image. That's what I'm worried about. Any suggestions? Never used g4u...I know that with partimage, if I imaged, say, a 4 gig drive, then pulled it down to a 6 gig drive and booted Windows, Windows (2000) would see 4 gig. I had to use a partition editor (there was a graphical one on one of the Linux rescue CDs) that I used to enlarge the partition, and Win2k didn't seem to care at all. Qtparted, maybe? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
--- Ken Stevenson <[EMAIL PROTECTED]> wrote: > Peter wrote: > > > > I intend to use g4u. I have done some preliminary testing and I am > quite > > confident that I can upload and download an image. I am now wondering > > about the situation where I need to recreate the partition that is to > > contain the image. It needs to be exactly the same size (sectors) as > the > > image. That's what I'm worried about. Any suggestions? > > > > You don't create a partition to restore to when you're using g4u. It > does a bit by bit copy so it creates the slice and partitions for you > automatically. Rock on! I missed that part I guess. Looks like I'm all set with g4u then. Thanks a million. __ Find your next car at http://autos.yahoo.ca ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
Peter wrote: I intend to use g4u. I have done some preliminary testing and I am quite confident that I can upload and download an image. I am now wondering about the situation where I need to recreate the partition that is to contain the image. It needs to be exactly the same size (sectors) as the image. That's what I'm worried about. Any suggestions? You don't create a partition to restore to when you're using g4u. It does a bit by bit copy so it creates the slice and partitions for you automatically. As the documentation for g4u says, it's most useful when the source disk and target disk are the same size. It works when the target disk is bigger, but the slice will only be as big as the original slice. -- Ken Stevenson Allen-Myland Inc. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
--- Bart Silverstrim <[EMAIL PROTECTED]> wrote: > > On Feb 10, 2006, at 9:50 AM, Giorgos Keramidas wrote: > > > On 2006-02-10 09:44, Peter <[EMAIL PROTECTED]> wrote: > >> --- Giorgos Keramidas <[EMAIL PROTECTED]> wrote: > As long as the "new" slice had enough space, geometry shouldn't > matter to dump|restore > >>> > >>> Right :) It also allows restoring in a different partition layout. > >> > >> Any chance of there being a way like this to restore to windows > >> systems > >> from the FreeBSD box? > > > > Not really. I'm far from being a Windows expert though, so YMMV. > > As an image? Look up partimage and partimaged. We've had some luck > restoring from both a Linux system running the Partimaged daemon and > booting from a Linux disk and restoring images off a samba/Windows > share using partimage. I intend to use g4u. I have done some preliminary testing and I am quite confident that I can upload and download an image. I am now wondering about the situation where I need to recreate the partition that is to contain the image. It needs to be exactly the same size (sectors) as the image. That's what I'm worried about. Any suggestions? __ Find your next car at http://autos.yahoo.ca ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
Giorgos Keramidas wrote: On 2006-02-09 14:36, Martin McCormick <[EMAIL PROTECTED]> wrote: After installing FreeBSD5.4, the ISC dhcp server and ISC bind on a hard drive, I wanted to clone that drive to a second drive so as to generate a second server, using what I had already installed as a template. I used the following command: dd if=/dev/da0 of=/dev/da1 bs=512 It turns out that dd defaults to 512-byte blocks so I didn't really need the bs=512, but I am not sure I haven't made some other type of mistake. The dd command has been running for about 4 hours on a very fast system, with a 1-gig processor, 1 gig of RAM and two 31-GB drives. One would think it should have finished by now, but it is still running. Is this a valid method of copying the entire contents of one drive to another? Thank you. Bah! That's too slow for my taste. I would usually go for a newfs, dump, and restore option. For instance, to create a copy of /usr on a second disk: newfs -U /dev/ad1s1a mount /dev/ad1s1a /mnt dump -0 -a -L /usr | ( cd /mnt ; restore ruvf - ) Copying with dd(1) is not as fast :) I had to clone a couple systems a while back, and I also did it with dump/restore. The best part was this was the first time I actually restored my backups to a bare hard drive. It gave me a lot of confidence that my backups actually work. I think a lot of people find out too late that whatever backup solution they're using is flawed and they can't rebuild their system from it. -- Ken Stevenson Allen-Myland Inc. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
On Feb 10, 2006, at 9:50 AM, Giorgos Keramidas wrote: On 2006-02-10 09:44, Peter <[EMAIL PROTECTED]> wrote: --- Giorgos Keramidas <[EMAIL PROTECTED]> wrote: As long as the "new" slice had enough space, geometry shouldn't matter to dump|restore Right :) It also allows restoring in a different partition layout. Any chance of there being a way like this to restore to windows systems from the FreeBSD box? Not really. I'm far from being a Windows expert though, so YMMV. As an image? Look up partimage and partimaged. We've had some luck restoring from both a Linux system running the Partimaged daemon and booting from a Linux disk and restoring images off a samba/Windows share using partimage. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
On 2006-02-10 09:44, Peter <[EMAIL PROTECTED]> wrote: >--- Giorgos Keramidas <[EMAIL PROTECTED]> wrote: >>> As long as the "new" slice had enough space, geometry shouldn't >>> matter to dump|restore >> >> Right :) It also allows restoring in a different partition layout. > > Any chance of there being a way like this to restore to windows systems > from the FreeBSD box? Not really. I'm far from being a Windows expert though, so YMMV. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
--- Giorgos Keramidas <[EMAIL PROTECTED]> wrote: > On 2006-02-09 18:48, Kevin Kinsey <[EMAIL PROTECTED]> wrote: > >Giorgos Keramidas wrote: > >> Bah! That's too slow for my taste. I would usually go for a newfs, > >> dump, and restore option. For instance, to create a copy of /usr on > a > >> second disk: > >> > >>newfs -U /dev/ad1s1a > >>mount /dev/ad1s1a /mnt > >>dump -0 -a -L /usr | ( cd /mnt ; restore ruvf - ) > >> > >> Copying with dd(1) is not as fast :) > > > > Sorry to butt in --- but I'm needing to start cloning too. Looks > > like a winner to me ... wouldn't this have the added advantage > > of making "same size and geometry" (cf. Erik Trulsson, 4 hours ago, > > this thread) less relevant? > > Yes, this is pretty much the important point :) > > > As long as the "new" slice had enough space, geometry shouldn't > > matter to dump|restore > > Right :) It also allows restoring in a different partition layout. > Any chance of there being a way like this to restore to windows systems from the FreeBSD box? __ Find your next car at http://autos.yahoo.ca ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
Paul Schmehl quotes and then writes: >> Copying with dd(1) is not as fast :) > >Have you tried dcfldd? sysutils/dcfldd Thank you. I hadn't thought of that. This is what I appreciate about groups like this. Martin McCormick WB5AGZ Stillwater, OK Systems Engineer OSU Information Technology Department Network Operations Group ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
On 2006-02-09 18:48, Kevin Kinsey <[EMAIL PROTECTED]> wrote: >Giorgos Keramidas wrote: >> Bah! That's too slow for my taste. I would usually go for a newfs, >> dump, and restore option. For instance, to create a copy of /usr on a >> second disk: >> >>newfs -U /dev/ad1s1a >>mount /dev/ad1s1a /mnt >>dump -0 -a -L /usr | ( cd /mnt ; restore ruvf - ) >> >> Copying with dd(1) is not as fast :) > > Sorry to butt in --- but I'm needing to start cloning too. Looks > like a winner to me ... wouldn't this have the added advantage > of making "same size and geometry" (cf. Erik Trulsson, 4 hours ago, > this thread) less relevant? Yes, this is pretty much the important point :) > As long as the "new" slice had enough space, geometry shouldn't > matter to dump|restore Right :) It also allows restoring in a different partition layout. I used this recently to 'recover' my laptop's installation, using a spare partition. Before running 'installkernel' and 'installworld', a backup of my root, /var and /usr partitions was saved with: # cd /home/backup # dump -o -aL -f root.ad0s1a / # dump -o -aL -f var.ad0s1d /var # dump -o -aL -f usr.ad0s1e /usr A 'copy' of the original /, /var and /usr was restored in ad0s2a, which was a single UFS partition, large enough to hold a restored copy of my old /, /var and /usr partitions: # newfs -U /dev/ad0s2a # mount /dev/ad0s2a /mnt # ( cd /mnt; restore -ruf /home/backup/root.ad0s1a ) # ( cd /mnt/var ; restore -ruf /home/backup/var.ad0s1d ) # ( cd /mnt/usr ; restore -ruf /home/backup/var.ad0s1e ) Then, when things went totally nuts after the installation of a new system on ad0s1* partitions, I could still boot from ad0s2a and restore my old backup copies from /home :) ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
Giorgos Keramidas wrote: On 2006-02-09 14:36, Martin McCormick <[EMAIL PROTECTED]> wrote: After installing FreeBSD5.4, the ISC dhcp server and ISC bind on a hard drive, I wanted to clone that drive to a second drive so as to generate a second server, using what I had already installed as a template. I used the following command: dd if=/dev/da0 of=/dev/da1 bs=512 It turns out that dd defaults to 512-byte blocks so I didn't really need the bs=512, but I am not sure I haven't made some other type of mistake. The dd command has been running for about 4 hours on a very fast system, with a 1-gig processor, 1 gig of RAM and two 31-GB drives. One would think it should have finished by now, but it is still running. Is this a valid method of copying the entire contents of one drive to another? Thank you. Bah! That's too slow for my taste. I would usually go for a newfs, dump, and restore option. For instance, to create a copy of /usr on a second disk: newfs -U /dev/ad1s1a mount /dev/ad1s1a /mnt dump -0 -a -L /usr | ( cd /mnt ; restore ruvf - ) Copying with dd(1) is not as fast :) Sorry to butt in --- but I'm needing to start cloning too. Looks like a winner to me ... wouldn't this have the added advantage of making "same size and geometry" (cf. Erik Trulsson, 4 hours ago, this thread) less relevant? As long as the "new" slice had enough space, geometry shouldn't matter to dump|restore Kevin Kinsey -- A committee is a group that keeps the minutes and loses hours. -- Milton Berle ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
--On Friday, February 10, 2006 00:01:23 +0200 Giorgos Keramidas <[EMAIL PROTECTED]> wrote: On 2006-02-09 14:36, Martin McCormick <[EMAIL PROTECTED]> wrote: After installing FreeBSD5.4, the ISC dhcp server and ISC bind on a hard drive, I wanted to clone that drive to a second drive so as to generate a second server, using what I had already installed as a template. I used the following command: dd if=/dev/da0 of=/dev/da1 bs=512 It turns out that dd defaults to 512-byte blocks so I didn't really need the bs=512, but I am not sure I haven't made some other type of mistake. The dd command has been running for about 4 hours on a very fast system, with a 1-gig processor, 1 gig of RAM and two 31-GB drives. One would think it should have finished by now, but it is still running. Is this a valid method of copying the entire contents of one drive to another? Thank you. Bah! That's too slow for my taste. I would usually go for a newfs, dump, and restore option. For instance, to create a copy of /usr on a second disk: newfs -U /dev/ad1s1a mount /dev/ad1s1a /mnt dump -0 -a -L /usr | ( cd /mnt ; restore ruvf - ) Copying with dd(1) is not as fast :) Have you tried dcfldd? sysutils/dcfldd It's both faster and more informative than dd. Cat the pkg-descr file. Paul Schmehl ([EMAIL PROTECTED]) Adjunct Information Security Officer University of Texas at Dallas AVIEN Founding Member http://www.utdallas.edu/ir/security/ ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
On 2006-02-09 14:36, Martin McCormick <[EMAIL PROTECTED]> wrote: > After installing FreeBSD5.4, the ISC dhcp server and ISC bind > on a hard drive, I wanted to clone that drive to a second drive so as > to generate a second server, using what I had already installed as a > template. I used the following command: > > dd if=/dev/da0 of=/dev/da1 bs=512 > > It turns out that dd defaults to 512-byte blocks so I didn't > really need the bs=512, but I am not sure I haven't made some other > type of mistake. The dd command has been running for about 4 hours on > a very fast system, with a 1-gig processor, 1 gig of RAM and two 31-GB > drives. One would think it should have finished by now, but it is > still running. Is this a valid method of copying the entire contents > of one drive to another? Thank you. Bah! That's too slow for my taste. I would usually go for a newfs, dump, and restore option. For instance, to create a copy of /usr on a second disk: newfs -U /dev/ad1s1a mount /dev/ad1s1a /mnt dump -0 -a -L /usr | ( cd /mnt ; restore ruvf - ) Copying with dd(1) is not as fast :) ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
I thought I was limited to only the block size of the disks. I am now trying a much larger block size as suggested and will see what happens. Many thanks. Martin McCormick ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
RE: Using dd to Make a Clone of a Drive
> [mailto:[EMAIL PROTECTED] On Behalf Of > Martin McCormick > Sent: Thursday, February 09, 2006 12:36 PM > To: freebsd-questions@freebsd.org > Subject: Using dd to Make a Clone of a Drive > > > After installing FreeBSD5.4, the ISC dhcp server and ISC bind > on a hard drive, I wanted to clone that drive to a second drive so as > to generate a second server, using what I had already installed as a > template. I used the following command: > > dd if=/dev/da0 of=/dev/da1 bs=512 > > It turns out that dd defaults to 512-byte blocks so I didn't > really need the bs=512, but I am not sure I haven't made some other > type of mistake. The dd command has been running for about 4 hours on > a very fast system, with a 1-gig processor, 1 gig of RAM and two 31-GB > drives. One would think it should have finished by now, but it is > still running. Is this a valid method of copying the entire contents > of one drive to another? Thank you. At this point, let it run. There was a discussion last month on the hackers distribution list on "increasing dd disk to disk transfer rate"; it discussed larger block size, piping (dd if=... | dd of=...), and disk_recover. It is also possible to create your own distribution disk, which may be appealing if you do a lot of cloning. Finally, there is always backup|restore. As for speed, dd will probably be last in a race, especially with large, mostly empty, disks. -gayn Bristol Systems Inc. 714/532-6776 www.bristolsystems.com ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
On Thu, 2006-02-09 at 14:36 -0600, Martin McCormick wrote: > After installing FreeBSD5.4, the ISC dhcp server and ISC bind > on a hard drive, I wanted to clone that drive to a second drive so as > to generate a second server, using what I had already installed as a > template. I used the following command: > > dd if=/dev/da0 of=/dev/da1 bs=512 > > It turns out that dd defaults to 512-byte blocks so I didn't > really need the bs=512, but I am not sure I haven't made some other > type of mistake. The dd command has been running for about 4 hours on > a very fast system, with a 1-gig processor, 1 gig of RAM and two 31-GB > drives. One would think it should have finished by now, but it is > still running. Is this a valid method of copying the entire contents > of one drive to another? Thank you. > > > Martin McCormick WB5AGZ Stillwater, OK > Systems Engineer > OSU Information Technology Department Network Operations Group > ___ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "[EMAIL PROTECTED]" -- Mike Jeays http://ca.geocities.com/[EMAIL PROTECTED] You can use a much bigger block size, and the job will take significantly less time to run. I have successfully used a blocksize of 512000. Keep it to a multiple of 512. I haven't tried even larger block sizes, but I think they would work fine. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Using dd to Make a Clone of a Drive
On Thu, Feb 09, 2006 at 02:36:18PM -0600, Martin McCormick wrote: > After installing FreeBSD5.4, the ISC dhcp server and ISC bind > on a hard drive, I wanted to clone that drive to a second drive so as > to generate a second server, using what I had already installed as a > template. I used the following command: > > dd if=/dev/da0 of=/dev/da1 bs=512 > > It turns out that dd defaults to 512-byte blocks so I didn't > really need the bs=512, but I am not sure I haven't made some other > type of mistake. The dd command has been running for about 4 hours on > a very fast system, with a 1-gig processor, 1 gig of RAM and two 31-GB > drives. One would think it should have finished by now, but it is > still running. Is this a valid method of copying the entire contents > of one drive to another? Thank you. The reason it is taking so long is almost certainly because you are using such a small blocksize. As it is 'dd' will read 512 bytes from da0, write those 512 bytes to da1, read another 512 bytes from da0 (which will probably mean waiting a couple of milliseconds for the head to get into the right position since the disk will have rotated sinc the last read), etc. The speed of your CPU, or the amount of RAM you have, is quite irrelevant in this case. If you try with bs=64k I can almost guarantee it will be a lot faster. Otherwise it is a perfectly good way of making a copy of a disk, provided both disks have the same size and geometry. -- Erik Trulsson [EMAIL PROTECTED] ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Using dd to Make a Clone of a Drive
After installing FreeBSD5.4, the ISC dhcp server and ISC bind on a hard drive, I wanted to clone that drive to a second drive so as to generate a second server, using what I had already installed as a template. I used the following command: dd if=/dev/da0 of=/dev/da1 bs=512 It turns out that dd defaults to 512-byte blocks so I didn't really need the bs=512, but I am not sure I haven't made some other type of mistake. The dd command has been running for about 4 hours on a very fast system, with a 1-gig processor, 1 gig of RAM and two 31-GB drives. One would think it should have finished by now, but it is still running. Is this a valid method of copying the entire contents of one drive to another? Thank you. Martin McCormick WB5AGZ Stillwater, OK Systems Engineer OSU Information Technology Department Network Operations Group ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"