Re: [gentoo-user] backup restore solution?
Jarry wrote: Hi, I am now looking for some sort of backup restore solution which would help me to get my gentoo-server up and running after fatal disk failure. I want to burn at regular intervals compressed partition images of disk on internal dvd/rw/ram (4.5 GB should be enough for archiving the whole disk, without /home partition). Well, tar and cpio are good choices because they are available on the Gentoo live CD. If you chose another program, you will just need to make sure that you have a static binary of it available at recovery time (copying this to your recovery media is the best choice). I am currently using 'dar' to backup to external USB hard disk. Dar is also useful for backing up to DVD media though, because it has good support for creating archive 'slices' that will fit nicely on a DVD, just in case you decide to backup /home as well. It is in portage, but if you are interested, check out http://dar.linux.free.fr/ For 'quick-and-easy' restoring, I'm not aware of anything that really automates the process. But generally the steps are: 1. fdisk 2. mkfs 3. mount 4. restore files 5. chroot 6. install boot loader 7. reboot The difficulty in restoring the files will really depend upon how you make your backups (always full, incrementals, differentials, etc). A full backup would always be the easiest, as you only need a single piece/set of media and one command to do the restore. The rest of the steps are pretty much exactly the same as for when you installed Gentoo, so there shouldn't be any real surprises there. One last thing, if you've only got a single CD/DVD drive, you are probably going to have an issue to have both the live CD and the backup media available, since you can't really eject the live CD to insert your backup disk. -Richard -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] backup restore solution?
Richard Fish wrote: I am currently using 'dar' to backup to external USB hard disk. I thought of this too, but I don't know how to power-off usb-disk remotelly. On the other side, after burning and unmounting dvd-r, dvd-drive stops spinning (kind of overheating protection)... 5. chroot, 6. install boot loader Is it not possible to archive MBR too? That way I could save 5. and 6., and to automate it with some scripts... One last thing, if you've only got a single CD/DVD drive, you are probably going to have an issue to have both the live CD and the backup Time to look for an old dvd-rom drive... Jarry -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] backup restore solution?
Jarry wrote: Is it not possible to archive MBR too? That way I could save 5. and 6., and to automate it with some scripts... Technically, yes, I guess you could do this. Although, I don't know if I would really recommend it. If you are using a stage 1.5 with grub, you would need to archive the first 63 blocks of the disk (technically fewer than that, but you would have to check grub-install's output to be sure of the exact count, and 63 is the safe number). This is because grub embeds the stage1.5 loader after the mbr (first block) and the start of the first partition. If you are not using the stage 1.5, or you are using lilo, then you have little choice but to reinstall the boot loader. This is because some files in /boot are block mapped into the mbr, and the restore process may have changed the layout of these files, so the block map will be incorrect. I think the safest route is to always let the system write a fresh mbr. -Richard -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] backup restore solution?
Richard Fish wrote: Jarry wrote: Is it not possible to archive MBR too? That way I could save 5. and 6., and to automate it with some scripts... Technically, yes, I guess you could do this. Although, I don't know if I would really recommend it. If you are using a stage 1.5 with grub, you would need to archive the first 63 blocks of the disk (technically fewer than that, but you would have to check grub-install's output to be sure of the exact count, and 63 is the safe number). This is because grub embeds the stage1.5 loader after the mbr (first block) and the start of the first partition. If you are not using the stage 1.5, or you are using lilo, then you have little choice but to reinstall the boot loader. This is because some files in /boot are block mapped into the mbr, and the restore process may have changed the layout of these files, so the block map will be incorrect. I think the safest route is to always let the system write a fresh mbr. -Richard It make sense but is easily bypassable using hda1 as boot partition AND it's the first on disk, with a little help from fdisk and dd (## are shell commands # comm.inside fdisk): hikky trikky ##fdisk /dev/hda #Command (m for help): u Changing display/entry units to sectors #Command (m for help): p Disk /dev/hda: 40.0 GB, 40027029504 bytes 255 heads, 63 sectors/track, 4866 cylinders, total 78177792 sectors Units = sectors of 1 * 512 = 512 bytes Device Boot Start End Blocks Id System /dev/hda1 * 63 979964 489951 83 Linux #Command (m for help): q ##dd if=/dev/hda of=MBR-boot.backup bs=512 count=489951 hikky trikky MBR-boot.backup now contain your MBR + the boot partition. now three question: a) I know noone that use this backup method, is it affidable ? b) What happen if it need to be restored on another disk c) HOW do I restore (hint man dd) Another hint: always try at least one restore after a choice of backup method, the rule is you never know . cheers Francesco -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] backup restore solution?
Bastian Balthazar Bux wrote: Device Boot Start End Blocks Id System /dev/hda1 * 63 979964 489951 83 Linux #Command (m for help): q ##dd if=/dev/hda of=MBR-boot.backup bs=512 count=489951 You missed a few! :-) The actual number of 512-byte blocks is 979964 - 63 + 1 = 979902. Fdisk always reports 1k blocks in the Blocks column. Or if an odd number of 512-byte blocks, the number of 1k blocks with a '+' afterwards. Plus, you want the mbr as well, plus whatever is between blocks 0 and 63, so better option might be: dd if=/dev/hda of=parttbl+mbr+boot.backup bs=512 count=979965 -Richard -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] backup restore solution?
Richard Fish wrote: Bastian Balthazar Bux wrote: Device Boot Start End Blocks Id System /dev/hda1 * 63 979964 489951 83 Linux #Command (m for help): q ##dd if=/dev/hda of=MBR-boot.backup bs=512 count=489951 You missed a few! :-) The actual number of 512-byte blocks is 979964 - 63 + 1 = 979902. Fdisk always reports 1k blocks in the Blocks column. Or if an odd number of 512-byte blocks, the number of 1k blocks with a '+' afterwards. Plus, you want the mbr as well, plus whatever is between blocks 0 and 63, so better option might be: yay, crossing eyes: s/so better option might be/the right option is/ dd if=/dev/hda of=parttbl+mbr+boot.backup bs=512 count=979965 -Richard Otherwise you can simply read the value under End (+1) instead of the one under Blocks ;) -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] backup restore solution?
On Sun, 31 Jul 2005 13:48:09 +0200, Richard Fish wrote: For 'quick-and-easy' restoring, I'm not aware of anything that really automates the process. But generally the steps are: 1. fdisk 2. mkfs 3. mount 4. restore files 5. chroot 6. install boot loader 7. reboot Partition image will handle everything by stage 1 with a single command. You may need to run the bootloader to set it up,although there is an option in partimage to backup the MBR. One last thing, if you've only got a single CD/DVD drive, you are probably going to have an issue to have both the live CD and the backup media available, since you can't really eject the live CD to insert your backup disk. Doesn't The Gentoo CD have an option to load the compressed filesystem into RAM, so you can unmount the CD? If it doesn't, plenty of others do. It doesn't have to be a Gentoo CD, just any live Cd containing the necessary restore commands. Another alternative is to include the Live CD components on the DVD, so you have a full restore from a single bootable disc. This normally involves copying the contents of the Live CD to the DVD image and using the mkisofs arguments listed in the isolinux documentation to make it bootable. -- Neil Bothwick Did you know that eskimos have 17 different words for linguist ? pgpjX25DhmRo6.pgp Description: PGP signature
[gentoo-user] backup restore solution?
Hi, I am now looking for some sort of backup restore solution which would help me to get my gentoo-server up and running after fatal disk failure. I want to burn at regular intervals compressed partition images of disk on internal dvd/rw/ram (4.5 GB should be enough for archiving the whole disk, without /home partition). But what I also need is fast and reliable restore function, for the case that all I have is a new replacement-disk, gentoo installation cd, and dvd/rw/ram with archived partition images (+ restore sw on floppy). Could you recommend me some software? I checked software in app-backup, but there is nothing about quick easy restoring... Jarry -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] backup restore solution?
On Sat, 30 Jul 2005 19:24:06 +0200, Jarry wrote: But what I also need is fast and reliable restore function, for the case that all I have is a new replacement-disk, gentoo installation cd, and dvd/rw/ram with archived partition images (+ restore sw on floppy). Could you recommend me some software? I checked software in app-backup, but there is nothing about quick easy restoring... For restoring entire partitions, backups made with tar or partimage are good. In either case, a single command is all you need to restore the partition. -- Neil Bothwick Like an atheist in a grave: all dressed up and no place to go. pgpwd9vtm46VK.pgp Description: PGP signature
