Sorry, no I did not mean you could do 3-way mirror with 2 disks, you'd need 3 disks for that. I had the impression you were looking to use 6 disks in one pool, and if you use 2-way mirrors, then that would imply 3 pairs of disks, that is where that 3 came from.
One pool can have multiple vdevs (and usually does for sizeable storage pools), and each vdev uses a fixed redundancy scheme - a mirror vdev is a byte-for-byte copy across all​ of its member disks, no matter how many members it has. To get multiple 2-way mirror sets in a pool, you need multiple vdevs. Tim ________________________________ From: Harry Putnam <rea...@newsguy.com> Sent: Monday, November 9, 2020 10:49 AM To: openindiana-discuss@openindiana.org <openindiana-discuss@openindiana.org> Subject: Re: [OpenIndiana-discuss] what to setup with 4 matched disks Bob Friesenhahn <bfrie...@simple.dallas.tx.us> writes: [...] > With only a small number of disks (and to aid human comprehension when > something goes wrong) I suggest using mirrors with a regular pool > 'scrub' schedule. With more disks raidz2 starts making sense but > raidz2 is less flexible. Thanks to all posters, lots of good input. Sounds like I need to stay with my tried and true setup. 1 mirrored matched disc boot vdev, 2 mirrored vdevs of 2 disks each so 6 disks making 3 pools in all. rpool, p0, p1. Someone (T Coalson)mentioned 3 way mirror with 2 disks. I must admit I do not understand how that is even possible. I guess my concept of mirror is stuck at 2 matched disks set as mirror, in a pool. T Coalson wrote: > By "1 vdev of 3 sets of 2disk mirrors", do you mean a vdev > specification "mirror dev1 dev2 dev3 dev4 dev5 dev6"? That doesn't > make 2-way mirrors, it makes a 6-way mirror with usable capacity equal > to one disk. In zfs, "mirror" doesn't imply "pair". I think what you > were looking for is 3 mirror vdevs with 2 disks in each. I'm afraid I'm really not understand this. I had gotten the impression somewhere that it was possible to have 3 different mirrors each containing different data inside one vdev. (I've never tried anything like that) But, now that you drew that out a bit; what I was saying sounds completely ridiculous. I think I am still not understanding the concept of `mirror'. 3 way mirror with 2 disks does not fit my incorrect understanding at all. What I've ever actually done is install 3 pairs of matched disks and created 3 pools from them. (I meant `matched' in the sense of 2 disks match each other (same brand, same size) in each pool, not that all disks match each other). And I'm currently experimenting (on VBox vm) with 1 matched pair of boot disks in a 2 disk mirror, and 7 bigger matched disks in raidz2. My first try at anything but 2 disk mirrors. _______________________________________________ openindiana-discuss mailing list openindiana-discuss@openindiana.org https://openindiana.org/mailman/listinfo/openindiana-discuss _______________________________________________ openindiana-discuss mailing list openindiana-discuss@openindiana.org https://openindiana.org/mailman/listinfo/openindiana-discuss