On Thursday 05 December 2019 16:16:58 Nathan Stratton Treadway wrote: > On Tue, Dec 03, 2019 at 15:43:10 +0100, Stefan G. Weichinger wrote: > > I consider recreating that holding disk array (currently RAID1 of 2 > > disks) as RAID0 .. > > Just focusing on this one aspect of your question: assuming the > filesystem in question doesn't have anything other than the Amanda > holding-disk area on it, I suspect you would be better off creating > two separate filesystems, one on each underlying disk, rather than > making them into a RAID0 array. > > Amanda can make use of two separate holding-disk directories in > parallel, so you can still get twice the total holding disk size > avilable in a run (compared to the current RAID1 setup), but Ananda's > parallel accesses will probably cause less contention on the physical > device since each filesystem is stored independently on one drive. > > > (Also, if one of the drives fails the other holding disk filesystem > will still be available, while if you are using RAID0 one drive > failing will take out the whole array....) > > Nathan
I find this an interesting concept Nathan, and would like to explore it further. In my setup here, serving this machine and 4 others in my machine shop menagery (sp?), I have 4 boxes of spinning rust. The first, /dev/sda contains the current operating system. This includes /usr/dumps as a holding disk area. The next box of rust, /dev/sdb, is the previous os, kept in case I need to go get something I forgot to copy over when I first made the present install. It also contains this /user/dumps directory but currently unused as it normally isn't mounted. Wash, rinse and repeat for /dev/sdc. normally not mounted. /dev/sdd is /amandatapes, mounted full time, (I find keeping a disk spinning results is disks that last 100,000+ hours with no increase in error rates, I have a 1T that had 25 bad, reallocated sectors the first time I checked it at about 5k hours in 2006, still has the same 25 reallocated sectors today at about 100,000 head flying hours.) What would be the effect of moving from a single holding area on /dev/sda as it is now operated, compared to mounting and using the holding directorys that already exist on /dev/sdb and /dev/sdc? Seems to me this should result in less pounding on the /dev/sda seek mechanism while backing up /dev/sda as it would move those writes to a different spindle, with less total time spent seeking overall. Am I on the right track? How does amanda determine which holding disk area to use for a given DLE in that case? Thanks. > ---------------------------------------------------------------------- >------ Nathan Stratton Treadway - natha...@ontko.com - Mid-Atlantic > region Ray Ontko & Co. - Software consulting services - > http://www.ontko.com/ GPG Key: > http://www.ontko.com/~nathanst/gpg_key.txt ID: 1023D/ECFB6239 Key > fingerprint = 6AD8 485E 20B9 5C71 231C 0C32 15F3 ADCD ECFB 6239 Copyright 2019 by Maurice E. Heskett Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene>
