On Wed, 2020-11-04 at 13:39 -0800, Paul Heinlein wrote: > On Wed, 4 Nov 2020, Russell Senior wrote: > > I think that the following is what I need to create the RAID: > > sudo mdadm --verbose --create /dev/md1 --level=0 --raid-devices=4 > /dev/nvme1 /dev/nvme2 /dev/nvme3 /dev/nvme4 >
Since you removed the partitions - what you listed is the correct usage. Then you create partition/format /dev/md1 - gparted should see it. Followed by normal mount. > > My nvme foo is weak, but I think your partition on an nvme is going > > to > > look like /dev/nvme1n1p1 or something. I just checked one of my > > machines and confirmed that naming. > > > > so, modify your mdadm command to use /dev/nvme1n1p1 /dev/nvme2n1p1 > > /dev/nvme3n1p1 /dev/nvme4n1p1 at the end. > > > > > > On Wed, Nov 4, 2020 at 1:04 PM John Jason Jordan <[email protected]> > > wrote: > > > > > > On Tue, 03 Nov 2020 16:51:38 -0800 > > > TomasK <[email protected]> dijo: > > > > > > > Correct - you need to setup ordinary SW raid - follow mdadm > > > > documentations. > > > > > > > > https://www.educba.com/what-is-raid-in-linux/ > > > > https://raid.wiki.kernel.org/index.php/RAID_setup > > > > in this order .... > > > > > > OK, software RAID is what I need. That eliminates the problems > > > you > > > discussed, plus I can't figure out how to use whatever RAID > > > features > > > exist on the PCIe cards that the U.2 drives are physically > > > mounted on, > > > so to heck with them. > > > > > > My first problem was that mdadm was not installed. This computer > > > has > > > Xubuntu 20.04.1, so that surprised me. But no trouble, apt was > > > happy to > > > install it. > > I will ever so humbly and politely throw my wrench in here... > > Have you considered using ZFS rather than mdadm+xfs/ext? Ubuntu > 20.04 > has native packages. I find it easier to maintain than a mdadm > device, > plus you get compression (if you'd like) and checksumming for free. > > You can easily create setups akin to RAID1, RAID5, RAID6, or RAID10. > E.g., for RAID10 > > # install the package > apt install zfsutils-linux > > # create a pool named 'myarchive' with a mirrored device > zpool create myarchive mirror nvme1 nvme2 > > # add a second mirrored to device to 'myarchive' > zpool add myarchive mirror nvme3 nvme4 > > # create a zfs filesystem in the the 'myarchive' pool, > # mounting it as /data and enabling default compression > zfs create \ > -o compression=on \ > -o mountpoint=/data \ > myarchive/data > > > > Anyway, that's my troublemaking for the day... > > This would be good time/place to mention GPL compatible btrfs - avoiding traditional mdadm: # Create a filesystem across four drives (metadata mirrored, linear data allocation) mkfs.btrfs -d single /dev/nvme1 /dev/nvme2 /dev/nvme3 /dev/nvme4 # Stripe the data without mirroring, metadata are mirrored mkfs.btrfs -d raid0 /dev/nvme1 /dev/nvme2 /dev/nvme3 /dev/nvme4 # mount it referring to any of your nvme mount /dev/nvme4 /mnt Advantages over other setup (including zfs): you can both add and remove device from the pool. # add device to the pool: btrfs device add /dev/sdc /mnt # if it is raid and not JBOD (single) pool - to balance the stripes # btrfs filesystem balance /mnt # remove device from the pool btrfs device delete /dev/sdc /mnt + compression, ....... at mount or per file/directory by chattr Just saying - no intention to make this post-election time any harder. Tomas _______________________________________________ PLUG: https://pdxlinux.org PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
