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Am Sun, Dec 11, 2022 at 08:44:42AM -0700 schrieb Mark Knecht: |
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> Also, I think there are ways for you to build complex pools like a RAID0 |
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> from your 6TB and 8TB drives, and then a RAID1 using the RAID0 and your |
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> 14TB drive but I've never tried it because mine don't have enough drive |
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> slots for that. |
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After a longer fruitless search on the interwebs (I ddidn’t want to start up |
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my NAS just to check this) I finally found the right search keywords and |
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found a reddit thread about that. And it even throws LVM into the |
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discussion. ^^ |
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https://www.reddit.com/r/zfs/comments/fitc73/raidz_with_nested_vdevs/ |
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Also <https://zfs-discuss.zfsonlinux.narkive.com/g2THW8n4/nested-vdevs>: |
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“Here's a definitive answer from the man page for zpool. |
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Virtual devices cannot be nested, so a mirror or raidz virtual device can |
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only contain files or disks. Mirrors of mirrors (or other combinations) are |
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not allowed.” |
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I would advise against a JBOD pool anyways. Because if one drive dies, the |
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whole JBOD is gone. That goes for ZFS and probably for LVM, too (though I am |
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not sure how writes are distributed across JBOD disks). If the goal is |
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redundancy, you could buy a second drive to match the size of an existing |
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one and build a mirror. If redundancy is not a goal, then use the drives |
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separately like you do now. If one fails, then only its content is gone (or |
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even just the files sitting on the broken sector). |
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> Also, turn on compression. It saves me between 15-20% so 14TB becomes 16TB |
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> storage. YMMV. Video files don't compress, at least not much. Data files |
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> generally do. |
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It doesn’t hurt to switch it on, especially with lzo. But with video, the |
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benefit will be negligible. When storing a block of data (a “record” in ZFS |
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speak), it is passed through the compressor and only if the compression gain |
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is above a given threshold (10 % methinks), the block is written to disk |
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with compression. |
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What is more relevant in filesystems for big files (i.e. videos): set the |
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record size to 1 MB. The default is 64 kB, IIRC. Each record requires one |
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block of metadata (which includes the record checksum). So bigger records → |
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fewer meta blocks → better storage efficiency. |
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If you use big records for small files, then efficiency goes down a little. |
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It’s a similar (but a little more complicated) principle as when you write a |
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100 byte text file to a file system that uses 4 kB clusters. That file will |
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still use up 4 kB on disk. |
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The record size can be set per-dataset. So in your pool you could create a |
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dataset with a smaller record size for office documents, images and music, |
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and another dataset just for videos. |
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> Hope this helps. I think you'll find TrueNAS fun actually but there is a |
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> learning curve. I've used it for about a year and barely scratched the |
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> surface. |
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The main reason for me why I would wanna use it as opposed to a standard |
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Gentoo install: the OOTB web interface to manage all sorts of accounts, |
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access and permissions under one nice hood. |
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-- |
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Grüße | Greetings | Salut | Qapla’ |
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Please do not share anything from, with or about me on any social network. |
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A fermata comes to the doctor: “I can’t hold it any longer...” |
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