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0

It seems the RAID metadata got damaged somehow. How did that happen? Once you've fixed any misconfigurations, errant scripts, hardware problems, etc., try to mount read-only: mkdir /mnt/{sdb1,sdc1} mount -o ro,loop,offset=$((2048*512)) /dev/sdb1 /mnt/sdb1 mount -o ro,loop,offset=$((2048*512)) /dev/sdc1 /mnt/sdc1 See if either one mounts, verify files of ...


2

I assume you did a fresh install and added the drives to the new computer. First do a: mdadm --assemble --scan and look in /proc/mdstat if the array has been activated. Then run: mdadm --examine --scan >> /etc/mdadm/mdadm.conf to get the config information in your new mdadm.conf again.


0

It's clean, that's good. It's inactive, that's not bad. Take a look e.g. here


0

It might be that parted is confused by the previous information on the disc, so you could wipe the first few sectors of each drive first dd if=/dev/zero of=/dev/sda bs=1k count=1 after that the following should work: parted /dev/sda unit TB mklabel gpt mkpart primary 0 4 print quit If you are planning to add the fourth drive afterwards, you should ...


1

sudo lvconvert --stripes 3 vg/lv /dev/sda1 /dev/sdb1 /dev/sdc1 Where 2 is the number of stripes, then the logical volume, then the 3 devices to stripe across. RAID 0 has no redundancy.


1

RAID10 does not accelerate any form of O_*SYNC, at least not for small files. You're writing 512b at a time, and after each write forcing it out to disk (plus the metadata required to read it back, e.g., file size). That requires RAID10 writes to at least 2 disks, probably 4 (i.e., all your disks). And all those writes need to be completed before it can ...


-1

You're not doing "100b" (byte? blocks? what was your intention?) chunks, you're doing 512 byte chunks. That is always slow because the RAID is using 512k chunks. That means that for every 512 bytes the RAID system has to read a 512k chunk, update 512 bytes in that chunk, compute its parity, and write the data + parity out to disk. It has to do the update, ...


0

Your dd command gives me 73.7 kB/s - on a SSD. So yes I guess it's normal. Or rather, dd just isn't a good benchmark. RAID certainly does not do any speedups for small files. Access times still remain the same, and for a small file that's what will take most of the effort for HDDs, getting the read head to the physical address of the file in the first place ...


0

Looks like somehow Debian installer screws up the partition table. The "bios_grub" flag gets removed and becomes "raid" flag. The fix is to rework the partition table again with parted and set it back. parted /dev/sda set 1 bios_grub on quit Same for /dev/sdb, and then chrooting and installing grub with answer from this question: How can I ...



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