* moving a working array @ 2022-06-24 13:38 o1bigtenor 2022-06-24 14:09 ` Wilson Jonathan 0 siblings, 1 reply; 9+ messages in thread From: o1bigtenor @ 2022-06-24 13:38 UTC (permalink / raw) To: Linux-RAID Greetings I have a working (no issues) raid-10 array in one box. Want to move it to another (new) box. Please - - - a list of the software steps? (the physical moving is the easy part - - - the new box has room for a lot of drives and is ready for these 4 easily) Just don't want a fubar situation because I've taken the wrong order or even wrong steps. The section 'using the array' has information but I'm not sure how that will work moving from one box to the other. (One question would be if the uuid of the array will remain the same as that would make things easier - - - I could copy the uuid from the existing and then just do the # mdadm --scan --assemble --uuid= blahblah ) TIA ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: moving a working array 2022-06-24 13:38 moving a working array o1bigtenor @ 2022-06-24 14:09 ` Wilson Jonathan 2022-06-24 14:49 ` Wols Lists 0 siblings, 1 reply; 9+ messages in thread From: Wilson Jonathan @ 2022-06-24 14:09 UTC (permalink / raw) To: o1bigtenor, Linux-RAID On Fri, 2022-06-24 at 08:38 -0500, o1bigtenor wrote: > Greetings > > I have a working (no issues) raid-10 array in one box. > > Want to move it to another (new) box. > > Please - - - a list of the software steps? > > (the physical moving is the easy part - - - the new box has room > for a lot of drives and is ready for these 4 easily) > > Just don't want a fubar situation because I've taken the wrong order > or even wrong steps. First make a backup... Second check the backup... Third make another backup... Fourth check that backup as well... Move disks... (I personally have just amended the /etc/mdadm/mdadm.conf file to include the uuid prior to moving disks and been good to go. BUT if I'd have lost all the data, without backups, I'd not have been fussed as it could all have been recreated/downloaded so I guess it all depends on how important or unique the data is.) But if you've got a new machine, why not get new disks and set up a nice new clean raid and then just rsync the data accross. That way your old disks become the backup, to the data you've newly transfered to clean a clean array. > > The section 'using the array' has information but I'm not sure how > that will work moving from one box to the other. > > (One question would be if the uuid of the array will remain the same > as that would make things easier - - - I could copy the uuid from the > existing and then just do the # mdadm --scan --assemble --uuid= > blahblah ) > > TIA ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: moving a working array 2022-06-24 14:09 ` Wilson Jonathan @ 2022-06-24 14:49 ` Wols Lists 2022-06-27 10:41 ` what's wrong with RAID-10? (was "Re: moving a working array") David T-G 0 siblings, 1 reply; 9+ messages in thread From: Wols Lists @ 2022-06-24 14:49 UTC (permalink / raw) To: Wilson Jonathan, o1bigtenor, Linux-RAID On 24/06/2022 15:09, Wilson Jonathan wrote: > On Fri, 2022-06-24 at 08:38 -0500, o1bigtenor wrote: >> Greetings >> >> I have a working (no issues) raid-10 array in one box. Bummer. It's a raid-10. A raid-1 would have been easier. >> >> Want to move it to another (new) box. >> >> Please - - - a list of the software steps? >> >> (the physical moving is the easy part - - - the new box has room >> for a lot of drives and is ready for these 4 easily) >> >> Just don't want a fubar situation because I've taken the wrong order >> or even wrong steps. > > First make a backup... > > Second check the backup... > > Third make another backup... > > Fourth check that backup as well... Seconded. And thirded and fourthed. Actually, that might not be necessary ... > > Move disks... (I personally have just amended the /etc/mdadm/mdadm.conf > file to include the uuid prior to moving disks and been good to go. BUT > if I'd have lost all the data, without backups, I'd not have been > fussed as it could all have been recreated/downloaded so I guess it all > depends on how important or unique the data is.) > > But if you've got a new machine, why not get new disks and set up a > nice new clean raid and then just rsync the data accross. That way your > old disks become the backup, to the data you've newly transfered to > clean a clean array. > Yup. Do you need the old disks in your new system? If not, DON'T MOVE THEM and they'll be your backup. >> >> The section 'using the array' has information but I'm not sure how >> that will work moving from one box to the other. >> >> (One question would be if the uuid of the array will remain the same >> as that would make things easier - - - I could copy the uuid from the >> existing and then just do the # mdadm --scan --assemble --uuid= >> blahblah ) >> Yup. If you move the disks, the UUID won't change. What I went and did - which took some down-time because it was a pretty big array ... was to create my new array on new disks in the new system. Then I can't remember the syntax - I looked it up on the web - but I just did a cat //old-system/dev/old-array | network > //new-system/dev/newarray So you're basically copying your filesystem across the network from the old "disk" (array, actually) to the new equivalent on the new system. Worked a treat, apart from the time it took ... A major reason I went that route, rather than an rsync or whatever, is that my system has hard-links all over the place, and while the various filesystem copying mechanisms CAN handle it, they don't like it ... a device copy simply doesn't need to know anything about it. Cheers, Wol ^ permalink raw reply [flat|nested] 9+ messages in thread
* what's wrong with RAID-10? (was "Re: moving a working array") 2022-06-24 14:49 ` Wols Lists @ 2022-06-27 10:41 ` David T-G 2022-06-27 15:10 ` Wols Lists 0 siblings, 1 reply; 9+ messages in thread From: David T-G @ 2022-06-27 10:41 UTC (permalink / raw) To: Linux-RAID Wol, et al -- ...and then Wols Lists said... % % On 24/06/2022 15:09, Wilson Jonathan wrote: % > On Fri, 2022-06-24 at 08:38 -0500, o1bigtenor wrote: % > > % > > I have a working (no issues) raid-10 array in one box. % % Bummer. It's a raid-10. A raid-1 would have been easier. [snip] This tripped me. I presumed that the reason for -10, not least because he also said "these 4 drives", was because the array space is bigger than just one hard drive size, ie 6T on 4ea 3T drives. How would RAID-1 work for that storage? And why would it be easier than RAID-10? TIA :-D -- David T-G See http://justpickone.org/davidtg/email/ See http://justpickone.org/davidtg/tofu.txt ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: what's wrong with RAID-10? (was "Re: moving a working array") 2022-06-27 10:41 ` what's wrong with RAID-10? (was "Re: moving a working array") David T-G @ 2022-06-27 15:10 ` Wols Lists 2022-06-27 15:23 ` what's wrong with RAID-10? David T-G 2022-06-27 18:41 ` what's wrong with RAID-10? (was "Re: moving a working array") Reindl Harald 0 siblings, 2 replies; 9+ messages in thread From: Wols Lists @ 2022-06-27 15:10 UTC (permalink / raw) To: David T-G, Linux-RAID On 27/06/2022 11:41, David T-G wrote: > Wol, et al -- > > ...and then Wols Lists said... > % > % On 24/06/2022 15:09, Wilson Jonathan wrote: > % > On Fri, 2022-06-24 at 08:38 -0500, o1bigtenor wrote: > % > > > % > > I have a working (no issues) raid-10 array in one box. > % > % Bummer. It's a raid-10. A raid-1 would have been easier. > [snip] > > This tripped me. I presumed that the reason for -10, not least because > he also said "these 4 drives", was because the array space is bigger than > just one hard drive size, ie 6T on 4ea 3T drives. How would RAID-1 work > for that storage? And why would it be easier than RAID-10? > Just that raid-1 would have been a simple case of two drives, each a backup of the other. Keep one safe, put the other in the new system. With raid-10, it's much more complicated - you can't just do that :-( Cheers, Wol ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: what's wrong with RAID-10? 2022-06-27 15:10 ` Wols Lists @ 2022-06-27 15:23 ` David T-G 2022-06-27 18:41 ` what's wrong with RAID-10? (was "Re: moving a working array") Reindl Harald 1 sibling, 0 replies; 9+ messages in thread From: David T-G @ 2022-06-27 15:23 UTC (permalink / raw) To: Linux-RAID Wol, et al -- ...and then Wols Lists said... % % On 27/06/2022 11:41, David T-G wrote: % > % > ...and then Wols Lists said... % > % % > % Bummer. It's a raid-10. A raid-1 would have been easier. % > [snip] % > ... % > just one hard drive size, ie 6T on 4ea 3T drives. How would RAID-1 work % > for that storage? And why would it be easier than RAID-10? % > % Just that raid-1 would have been a simple case of two drives, each a backup % of the other. Keep one safe, put the other in the new system. OH!! That helps. I was bummer-ing the wrong aspect and trying to figure out why RAID-10 was a bad design choice. Now i get it :-) % % With raid-10, it's much more complicated - you can't just do that :-( Yeah. % % Cheers, % Wol Thanks again! :-D -- David T-G See http://justpickone.org/davidtg/email/ See http://justpickone.org/davidtg/tofu.txt ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: what's wrong with RAID-10? (was "Re: moving a working array") 2022-06-27 15:10 ` Wols Lists 2022-06-27 15:23 ` what's wrong with RAID-10? David T-G @ 2022-06-27 18:41 ` Reindl Harald 2022-06-27 18:52 ` Wols Lists 1 sibling, 1 reply; 9+ messages in thread From: Reindl Harald @ 2022-06-27 18:41 UTC (permalink / raw) To: Wols Lists, David T-G, Linux-RAID Am 27.06.22 um 17:10 schrieb Wols Lists: > On 27/06/2022 11:41, David T-G wrote: >> Wol, et al -- >> >> ...and then Wols Lists said... >> % >> % On 24/06/2022 15:09, Wilson Jonathan wrote: >> % > On Fri, 2022-06-24 at 08:38 -0500, o1bigtenor wrote: >> % > > >> % > > I have a working (no issues) raid-10 array in one box. >> % >> % Bummer. It's a raid-10. A raid-1 would have been easier. >> [snip] >> >> This tripped me. I presumed that the reason for -10, not least because >> he also said "these 4 drives", was because the array space is bigger than >> just one hard drive size, ie 6T on 4ea 3T drives. How would RAID-1 work >> for that storage? And why would it be easier than RAID-10? >> > Just that raid-1 would have been a simple case of two drives, each a > backup of the other. Keep one safe, put the other in the new system. > > With raid-10, it's much more complicated - you can't just do that :-( you can easily do that with RAID10 * just buy replacement disks * pull out two disks * look if it boots * if not pull a different out * rebuild the array with the new disks * put the other two disks with two blank ones in the other box * rebuild the array in the other box * voila you have two indetical redundant machines frankly i cloned machines by intention that way ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: what's wrong with RAID-10? (was "Re: moving a working array") 2022-06-27 18:41 ` what's wrong with RAID-10? (was "Re: moving a working array") Reindl Harald @ 2022-06-27 18:52 ` Wols Lists 2022-06-27 23:37 ` Reindl Harald 0 siblings, 1 reply; 9+ messages in thread From: Wols Lists @ 2022-06-27 18:52 UTC (permalink / raw) To: Reindl Harald, David T-G, Linux-RAID On 27/06/2022 19:41, Reindl Harald wrote: > > > Am 27.06.22 um 17:10 schrieb Wols Lists: >> On 27/06/2022 11:41, David T-G wrote: >>> Wol, et al -- >>> >>> ...and then Wols Lists said... >>> % >>> % On 24/06/2022 15:09, Wilson Jonathan wrote: >>> % > On Fri, 2022-06-24 at 08:38 -0500, o1bigtenor wrote: >>> % > > >>> % > > I have a working (no issues) raid-10 array in one box. >>> % >>> % Bummer. It's a raid-10. A raid-1 would have been easier. >>> [snip] >>> >>> This tripped me. I presumed that the reason for -10, not least because >>> he also said "these 4 drives", was because the array space is bigger >>> than >>> just one hard drive size, ie 6T on 4ea 3T drives. How would RAID-1 work >>> for that storage? And why would it be easier than RAID-10? >>> >> Just that raid-1 would have been a simple case of two drives, each a >> backup of the other. Keep one safe, put the other in the new system. >> >> With raid-10, it's much more complicated - you can't just do that :-( > > you can easily do that with RAID10 Only if all the disks are the same size ... and an even number ... Cheers, Wol ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: what's wrong with RAID-10? (was "Re: moving a working array") 2022-06-27 18:52 ` Wols Lists @ 2022-06-27 23:37 ` Reindl Harald 0 siblings, 0 replies; 9+ messages in thread From: Reindl Harald @ 2022-06-27 23:37 UTC (permalink / raw) To: Wols Lists, David T-G, Linux-RAID Am 27.06.22 um 20:52 schrieb Wols Lists: > On 27/06/2022 19:41, Reindl Harald wrote: >> >> >> Am 27.06.22 um 17:10 schrieb Wols Lists: >>> On 27/06/2022 11:41, David T-G wrote: >>>> Wol, et al -- >>>> >>>> ...and then Wols Lists said... >>>> % >>>> % On 24/06/2022 15:09, Wilson Jonathan wrote: >>>> % > On Fri, 2022-06-24 at 08:38 -0500, o1bigtenor wrote: >>>> % > > >>>> % > > I have a working (no issues) raid-10 array in one box. >>>> % >>>> % Bummer. It's a raid-10. A raid-1 would have been easier. >>>> [snip] >>>> >>>> This tripped me. I presumed that the reason for -10, not least because >>>> he also said "these 4 drives", was because the array space is bigger >>>> than >>>> just one hard drive size, ie 6T on 4ea 3T drives. How would RAID-1 >>>> work >>>> for that storage? And why would it be easier than RAID-10? >>>> >>> Just that raid-1 would have been a simple case of two drives, each a >>> backup of the other. Keep one safe, put the other in the new system. >>> >>> With raid-10, it's much more complicated - you can't just do that :-( >> >> you can easily do that with RAID10 > > Only if all the disks are the same size ... and an even number in other words: in every typical usecase how does RAID1 work with different disk sizes? the point is that "With raid-10, it's much more complicated" is simply wrong unledss you say "it can be more complicated if you have a strange setup" ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2022-06-27 23:37 UTC | newest] Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-06-24 13:38 moving a working array o1bigtenor 2022-06-24 14:09 ` Wilson Jonathan 2022-06-24 14:49 ` Wols Lists 2022-06-27 10:41 ` what's wrong with RAID-10? (was "Re: moving a working array") David T-G 2022-06-27 15:10 ` Wols Lists 2022-06-27 15:23 ` what's wrong with RAID-10? David T-G 2022-06-27 18:41 ` what's wrong with RAID-10? (was "Re: moving a working array") Reindl Harald 2022-06-27 18:52 ` Wols Lists 2022-06-27 23:37 ` Reindl Harald
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