Can anyone find some ZFS documentation. I explicitely want
an explanation of how it deals with links.
Docs written by Oracle are useless. They do not know how
to communicate with Linux people.
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It is a good start, thanks.
âŚ
Read the whole thing, and nowhere does it explain what a pool is?
Thanks, will give that a read!!!
Hi Neville,
I found these links. See if it is relevant to you.
https://wiki.debian.org/ZFS
https://wiki.archlinux.org/title/ZFS
Jorge
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Hi Jorge,
Thank you .
After reading several documents, I still have not discovered what a âpoolâ is?
Maybe your links will tell me
Regards
Neville
1 Like
Neville,
Are you talking about zpool?
https://arstechnica.com/information-technology/2020/05/zfs-101-understanding-zfs-storage-and-performance/
Jorge
2 Likes
At last something that explains how it works
Thank you Jorge.
There are plenty of documents that are ârecipe booksâ or
âsales brochuresâ ⌠real infornation on ZFS is scarce.
Thanks
Neville
3 Likes
This comment from Jorgeâs link seems to be an important consideration for home use of ZFS
Something I always understood was ZFS completely trusts
the data in RAM so any memory corruption can and will hose
the pool. My ZFS experience is all under FreeNAS. The advice
was always to build a system with ECC RAM if you plan to
store anything you care about at all.
I presume this hasnât changed, but itâs quite a consideration
for ZFS becoming available to the desktop.
There is a reply comnent
All filesystems, INCLUDING zfs, trust RAM.
But the way I read it, ZFS, being more complicated, is more susceptible to RAM corruption.
Who knows?
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I actually think ZFS is less complex than Logical Volume management⌠I kinda hate the whole :
- pvcreate
- vgcreate
- lvcreate
blah blah blah compared to ZFS⌠But with ZFS - you need to make sure you do it exactly right, from the outset - itâs not very forgiving for the unwary⌠and itâs caught me out in the past, trying to do stuff at the CLI - I tried replacing/adding a disk in my RAIDZ1-0 (i.e. RAID 5) i.e. 4 disks (with one as parity) and accidentally converted the whole thing into a stripe (RAID0) - i.e. the replacement disk was a concat - and I had zero redundancy. REMEMBER KIDDIES : RAID is NOT a backup solution!
I ended up having to use rsync and spend several days backing up my NAS to other media (i.e. hard drives internal and external on several of my Linux boxes) - and I rebuilt FreeNAS from scratch once everything was backed up.
I have zero information about ZFS on Linux⌠Last time I tried it - wasnât happy with performance, I was booting Ubuntu 20 or 22 off encrypted ZFS - and my sync software (Resilio Sync) was eating CPU with ZFS reads and writes - so I canned that idea and went back to ext4 on LUKS (with LVM) - which has negligible (unnoticeable) performance impact on Linux.
I also seem to recall Linus Torvalds in the last couple of years or thereabouts, said something less than positive about ZFS in the kernel or something?
But I love ZFS on FreeBSD (TrueNAS) - and itâs rock solid on Solaris too⌠Every now and then, for shits in giggles, Iâll build a Solaris x86 VM in VirtualBox - and re-learn how to add a 2nd disk to a zpool (i.e. converting it to a zfs mirror - RAIDZ0 ?)âŚ
Note : in 2021 I upgraded my 8 GB non-ECC RAM in my FreeNAS to 16 GB ECC. This is the same âbuildâ I deployed in late 2019 - back then it was FreeNAS (11?), but have inplace upgraded to TrueNAS âCoreâ 12 - but Iâm still on the fence about updating to TrueNAS âCoreâ 13 - I guess I should, 12 is now EOL.
But having said that - I have NEVER had any corruption issues with ZFS on FreeNAS in 12+ years (originally bought the HP N40L Microserver in late 2011) - i.e. most of that time was only using non-ECC RAM.
Interesting point : my house got a brownout yesterday - both my desktop machine, and my TrueNAS lost power, and stayed off⌠but a Pi4, a Pi3, an Orange Pi2E+ and my Gigabyte Brix (running RHEL 8) all stayed up. Anyway - I have a tiny (7" 4:3) VGA monitor hooked up as the console on the TrueNAS N40L - but - for some reason - itâs ALL in mirror writing! Canât figure out why - looks weird too 
x@baphomet î° ~ î° uptime
11:52AM up 5:48, 2 users, load averages: 0.37, 0.35, 0.28
x@baphomet î° ~ î° sudo zpool list
NAME SIZE ALLOC FREE CKPOINT EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT
BARGEARSE 14.5T 12.9T 1.58T - - 26% 89% 1.00x ONLINE /mnt
freenas-boot 238G 3.89G 234G - - - 1% 1.00x ONLINE -
x@baphomet î° ~ î° sudo zpool status BARGEARSE
pool: BARGEARSE
state: ONLINE
status: Some supported features are not enabled on the pool. The pool can
still be used, but some features are unavailable.
action: Enable all features using 'zpool upgrade'. Once this is done,
the pool may no longer be accessible by software that does not support
the features. See zpool-features(5) for details.
scan: scrub repaired 0B in 13:42:46 with 0 errors on Sun Nov 26 13:42:47 2023
config:
NAME STATE READ WRITE CKSUM
BARGEARSE ONLINE 0 0 0
raidz1-0 ONLINE 0 0 0
gptid/c4f70c63-044f-11e9-b5c1-441ea13dfb0c ONLINE 0 0 0
gptid/941cb3cb-31f4-11eb-98a0-441ea13dfb0c ONLINE 0 0 0
gptid/912aa5ba-329b-11eb-86e3-441ea13dfb0c ONLINE 0 0 0
gptid/ca979ae2-044f-11e9-b5c1-441ea13dfb0c ONLINE 0 0 0
errors: No known data errors
I have ALL the features I need - so no need to upgrade the pool far as I care⌠I guess I should upgrade both ZPOOLs before I contemplate doing an inplace upgrade to TrueNAS 13.0âŚ
I keep meaning to buy more spares for this N40L - e.g. a power supplyâŚ
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That may be so. Never tried LVM
All I meant was a system with a larger memory footprint is more likely to
intercept a cosmic ray.
and
a more complex system is more likely to have issues after a ram corruption.
I think both LVM and ZFS are way too much for the average home user.
I was looking because Gentoo and BSD are both pushing ZFS in desktop
systems⌠Why? What is the point of something as complicated as that
when all you have is one disk?
I can see it helping in your NAS. That is another world.
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Thatâs official documentation for you. It just assumed that you know it -_-
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I think , in some cases , it goes thru the Sales Department, and ends up
all superlatives and no information.
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Sadly - thatâs the case with a lot of the tech that Larry Ellison ransacked from Sun Microsystems⌠I LOATHE dealing with Oracle⌠conversely, dealing with Sun Microsystems was the best IT support Iâve EVER experienced!
Sun actually opensourced both Solaris, and ZFS, before Oracle bought them (I bet Larry Ellison was spewing when he got the lawyers involved to see if he could turn back time)⌠Thatâs how we got ZFS in FreeBSD and why it so mature on BSD UNIX-like systems - well - maybe FreeBSD anywayâŚ
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ZFS seems to work in my GhostBSD⌠its the default there.
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WOW!!! You guys are way over my head on this subject, I have enough problems just dealing with ntfs, ext2 and ext4. Good reading though!!!
Yes, Sun were really the best supplier in the 1980/90âs
CSIRO was full of Sun workstations.
Before then DEC were right up there.
Thatâs one of the ones that comes with a WM/DE/GUI by default right? XFCE?
Yeah. It defaults to Mate with official support
There is an Xfce Community Edition.
It is a real good effort at making an easily installable, ready to use, desktop.
But why did they choose ZFS? Trying to be modern maybe?
I was doing the Gentoo /etc/fstab today and had to put ext4 in place of zfs for the / file system. Why would Gentoo consider zfs?