On 11/01/20 20:55, Gandalf Corvotempesta wrote: > Il giorno sab 11 gen 2020 alle ore 20:11 Wol > <antlists@xxxxxxxxxxxxxxx> ha scritto: >> The "standard" as you call it is actually RAID1+0. This is *not* "linux >> raid10", which is as you describe it - the number of disks can be any >> number greater than the number of mirrors. > > Actually, what I need to do is simple: a scalable array with at least > 3way-mirrors. > > I've thought in using multiple 3way mirrors (RAID1) merged together with LVM or > just a single RAID10 (with 3 disks mirrors) and LVM on top of it as > volume manager. > > Don't know which one is better, the result is similar. > Multiple 3-way mirrors (1+0) requires disks in multiples of 3. Raid10 simply requires "4 or more" disks. If you expect/want to expand your storage in small increments, then 10 is clearly better. BUT. Depending on your filesystem - for example XFS - changing the disk layout underneath it can severely impact performance - when the filesystem is created it queries the layout and optimises for it. When I discussed it with one of the XFS guys he said "use 1+0 and add a fresh *set* of disks (or completely recreate the filesystem), because XFS optimises layout based on what disks it thinks its got." Cheers, Wol
