Safety Engineer, Dad, Husband, Pilot, Musician. Not necessarily in that order.

Ingenieur für funktionale Sicherheit, Vater, Ehemann, Pilot, Musiker. Nicht notwendigerweise in dieser Reihenfolge.

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Joined 1 year ago
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Cake day: June 11th, 2023

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  • Then why do you think manufacturers still list these failure rates (to be sure, it is marked as a limit, not an actual rate)? I’m not being sarcastic or facetious, but genuinely curious. Do you know for certain that it doesn’t happen regularly? During a scrub, these are the kinds of errors that are quietly corrected (althouhg the scrub log would list them), as they are during normal operation (also logged).

    My theory is that they are being cautious and/or perhaps don’t have any high-confidence data that is more recent.


  • Hopfgeist@feddit.detoSelfhosted@lemmy.worldHow to fix my ZFS pool mistakes
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    3 months ago

    Bit error rates have barely improved since then. So the probability of an error whenr reading a substantial fraction of a disk is now higher than it was in 2013.

    But as others have pointed out. RAID is not, and never was, a substitute for a backup. Its purpose is to increase availability. And if that is critical to your enterprise, these things need to be taken into account, and it may turn out that raidz1 with 8 TB disks is fine for your application, or it may not. For private use, I wouldn’t fret. but make frequent backups.

    This article was not about total disk failure, but about the much more insidious undetected bit error.


  • Let’s do the math:

    The error-reate of modern hard disks is usually on the order of one undetectable error per 1E15 bits read, see for example the data sheet for the Seagate Exos 7E10. An 8 TB disk contains 6.4E13 (usable) bits, so when reading the whole disk you have roughly a 1 in 16 chance of an unrecoverable read error. Which is ok with zfs if all disks are working. The error-correction will detect and correct it. But during a resilver it can be a big problem.


  • I also use this, and it works great. Another downside is that when using the free service, others can just use subdomains of your registered domains. You can always deny it, but you have to do it manually. With the premium subscriptions you can prevent that automatically for a number of domains, depending on how much you pay.


  • To add, unlike “traditional” RAID, ZFS is also a volume manager and can have an arbitrary number of dynamic “partitions” sharing the same storage pool (literally called a “pool” in zfs). It also uses checksumming to determine if data has been corrupted. On redundant setups it will then quietly repair the corrupted parts with the redundant information while reading.





  • I don’t think there’s anything intrinsically wrong, but far as I can see you are using only a single disk for the zfs pool, which will give you integrity checks (know when something is corrupted), but no way to fix it.

    Since this is, by today’s standards, a tiny disk at 100G, I assume this is just a test setup? I’m not sure zfs is particularly well suited for virtual machines, I think it is better to have the host handle the physical data integrity by having the disk image on a zfs filesystem, or giving the VM a zfs volume (block device) directly.






  • What are the advantages of raid10 over zfs raidz2? It requires more disk space per usable space as soon as you have more than 4 disks, it doesn’t have zfs’s automatic checksum-based error correction, and is less resilient, in general, against multiple disk failures. In the worst case, two lost disks can mean the loss of the whole pack, whereas raidz2 can tolerate the loss of any 2 disks. Plus, with raid you still need an additional volume manager and filesystem.



  • The manual says it works on “any phone or tablet”, running Android 7 or higher. Mine is a OnePlus 6T running LineageOS 20 (Android 13). On my much slower and less well-equipped Samsung Galaxy Tab A7 Lite LTE (3 GB RAM) it installs just fine. Would it really object to being installed just because the phone has an unlocked bootloader? It isn’t rooted, and even banking apps work fine.

    Strange. Maybe I’ll file a bug report. It looks like something I might spend $10 on if it works fine.



  • Yes. I use a G7 N36L as an offsite-backup server in my second apartment. Works great with NetBSD and zfs, using rsnapshot to make remote backups every night.

    Since it is only active for an hour and a half each night, it is my only server to put the disks into powersave mode the rest of the time. Computing eprformance is so low that I don’t even run a folding@home client. It usually cannot finish any work package before the deadline.