Re: [gentoo-user] NAS and replacing with larger drives

[Dale]

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


Interesting info.  Since this is a duplicate copy already, I'm not to
worried about RAID stuff.  I'd rather have two separate backups myself. 
Store them in different places for even more safety.  Still, one of
these days.  ;-) 

I'm still getting this error. 

root@fireball ~ # mkdir /mnt/Backup/Videos
mkdir: cannot create directory ‘/mnt/Backup/Videos’: Permission denied
root@fireball ~ #

I've tried every permission in every place I can find.  I have a user
set up, set permissions under storage and pools, all the little
directory thingys under it too.  It mounts so I'd think I got everything
set up correctly in the Share section.  I actually followed a guide and
I don't think I missed anything.  Still, I can't write anything to the
thing.  It mounts fine, even shows it is mounted rw.  I can't find
anything wrong on the puter or NAS ends.  This reminds me of the last
time I played with BSD.  It works so different, it just throws a person
upside down and shakes them. 

I did switch to TrueNAS tho.  Thing is, I got the same result from both,
exact same error.  Can't be a bug.  It has to be me.  No idea what I
missed but I bet I did.  lol  Just gonna keep banging on it.  :-D  I do
like the GUI part.  That's pretty neat. 

Dale

:-) :-)