On 07/30/2018 02:06 PM, Patrick O'Callaghan wrote: > On Mon, 2018-07-30 at 13:11 -0700, ToddAndMargo wrote: >> dump is awesome for backing up servers in the middle of >> the night. dump/restore are also blazingly fast > > IIRC one reason for that is that they don't walk the directory tree, > they just go through the inode table. This means that restoring > individual files can take a relatively long time (they have to be found > first by reconstructing the path from the root, which can mean a lot of > scanning back and forth), but as that's not the focus it's a reasonable > tradeoff.
dump was designed to feed a streaming, non-random access device like a tape system and it won't cross source devices. For flat-out speed, dump is slightly slower than dd but it is file-aware (which dd isn't). I'd imagine dumping to a seekable device (e.g. a file) might speed up restores, but a restore still has to recreate paths and things from the inodes (after reading in the filelist from the dump archive). I've never done it as I stopped using dump/restore way back when (I think it was ESIX SVR4 using a 5150-type QIC tape device back in the mid 80s). Personally, I prefer doing a file-oriented backup using rsync to an external device mounted somewhere. I typically use locally-connected external ESATA or thunderbolt devices, but USB3 isn't _that_ horrible. I've even done it over network links to rsync servers, either using the native rsync protocol or via a VPN using UDR when going over the big, bad Internet (a bit trickier, but damned near wire speed over the network--depending on the stoutness of the VPN devices). I take care to not back up things that may vary (e.g. /proc, /sys, /dev, logs I don't care about, user browser caches, etc.). This gives me a simple way to mount the external media and restore individual files or entire directory trees pretty easily. Not as fast as dump or dd, but running it at off hours (via cron or "at") makes it fairly painless. This is just my preference. Do what you will. ---------------------------------------------------------------------- - Rick Stevens, Systems Engineer, AllDigital ri...@alldigital.com - - AIM/Skype: therps2 ICQ: 226437340 Yahoo: origrps2 - - - - ...Had this been an actual emergency, we would have fled in terror - - and you'd be on your own, pal! - ---------------------------------------------------------------------- _______________________________________________ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org/message/2RIIV727IQQNHQMG7MCZVOXLIKR5DMXC/
