Ok I found sudo fdisk -l to see the drives... JT
On 2/20/2016 6:01 AM, Philipp Burch wrote: > Hi John! > > On 20.02.2016 12:34, John Thornton wrote: >> I see two ways to clone a HD on the web one using dd and one using tar. >> >> Boot from the live cd. Mount your destination media to (say) /mnt. >> >> dd if=/dev/sd whatever of=/mnt/mybackup.ddimg >> >> In this case what do they mean by mount? > It depends on what you want to achieve. If you want to clone a HD in a > two-step process going over an image file, then this approach is fine. > "Mounting" the destination media in this case just means to make it > accessible in the same way as you would do outside the LiveCD > environment, i.e. by doing it manually using something like > > # mount /dev/sdX /mnt > > or by clicking the drive in the file browser. If you plug in a removable > disk, it might also be mounted automatically. On recent versions of > Ubuntu, the standard mounting location is > > /media/username/drivename > > The directory /mnt is not special at all, it is just kind of a > convention to use it as a mount point for some media. But you could just > as easily create a folder on your desktop and mount the drive there. > > A few words to dd: You may get somewhat faster operation by letting it > working with larger chunks of data. I usually use something like > > # dd if=src of=dest bs=1M > > so that it reads and writes 1MiB blocks instead of the default (probably > 4kiB). If you know for sure that your source HD only contains data up to > some address, you can avoid creating an image padded with a lot of > unused data by limiting the amount of data to copy: > > # dd if=src of=dest bs=1M count=4000 > > This will copy 4000*1M=4GB of data and stop then. If you want to keep > the image around, it may also be a good idea to compress it on-the-fly. > This can be done by omitting the of=dest part, in which case dd will > output the data to stdout, from where it can be piped through gzip (or > another stream compression utility). But I'd need to look up the > required flags for gzip first. > >> Mount the source to /mnt, mount the destination to /home (say) >> >> tar cvfpz /home/mybackup.tar.gz /mnt >> >> does this tar create a copy of the whole disk? > Maybe. While dd operates on the raw disk file (e.g. /dev/sda, you > usually do NOT want /dev/sda1), tar takes all the files in the source > filesystem and puts them in an archive. This may save some space and > makes it easier to browse through the files, but it requires that you > partition and format a new disk before copying the archive back onto it. > > So, depending on the use-case, I'd suggest one of those variants: > > - If you want to create an exact clone of a drive and can connect both > the source and destination drive to your computer at the same time, then > use dd without compression and directly operating on the device files of > the two drives. I.e. > # dd if=/dev/sda of=/dev/sdb bs=1M > Make *really, really* sure that you do not mess up if and of, as dd > otherwise will happily overwrite your source drive! > > - If you want to create a backup image of an entire disk for later > copying to a fresh drive, use dd, maybe with the count flag and/or with > compression and store the output in a regular file somewhere convenient. > > - If you want to create a backup of only one file system and want to get > easy access to the individual files, use the tar approach. > > Good luck! > > Cheers, > Philipp > > > > ------------------------------------------------------------------------------ > Site24x7 APM Insight: Get Deep Visibility into Application Performance > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > Monitor end-to-end web transactions and take corrective actions now > Troubleshoot faster and improve end-user experience. Signup Now! > http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
