• Max-P
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    41 year ago

    People have been running Ext4 systems for decades pretending that if Ext4 does not see the bitrot, the bitrot does not exist. (then BTRFS picks up a bad checksum and people scold it for being a bad filesystem)

    ZFS made me discover that my onboard SATA controller sucks and returns bad data occasionally under heavy load. My computer cannot complete a ZFS scrub without finding errors, every single time.

    Ext4, bcache and mdadm never complained about it, ever. There was never any sign that something was wrong at all.

    100% worth it if you care about your data. I can definitely feel the hit on my NVMe but it’s also doing so much more.

    • yianiris
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      -11 year ago

      @Max_P @yote_zip

      A file system and a raid setup all in one with facebook’s code for de-/compression … yet another piece of software that tries to do the work for several others.

      ext4 will rarely have extreme loads unless all you do is backup and mirroring. For more accurate data read/write and better checks use xfs and external journaling. On M2 it is by far the fastest solution and far more secure than ext.

      • yianiris
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        1 year ago

        @Max_P @yote_zip

        On magnetic disk there is physical location for each bit of data written, for ssd it is all virtual space handled by internal software simulating a magnetic drive. The variation from disk to disk is much higher than the sensitivity of the fs.

        You want accuracy and reliability of data storage, use HDD and Raid!

        • Max-P
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          11 year ago

          RAID doesn’t checksum and heal the rotten data. It’s game over before you even have a filesystem on top of it, because said filesystem can’t directly access the underlying disks because of the RAID layer.

          Errors will occur, and RAID has no way of handling it. You have a RAID1, disk 1 says it’s a 0, disk 2 says it’s a 1. Who’s right? RAID can’t tell, btrfs and ZFS can. RAID won’t even notice there’s a couple flipped bits, it’ll just pass them along. ZFS will just retry the read on both disks, pick the block that matches the checksum, and write the correct data back on the other disk. That’s why people with lots of data loves ZFS and RAIDZ.

          The solution isn’t more reliable hardware, the solution software that can tell you and recover from your failing hardware.