Re: Homebuilt NAS: System Drive Filesystem?
On Sun, 23 Aug 2020 14:26:15 -0700
David Christensen <dpchrist@holgerdanske.com> wrote:
> On 2020-08-23 11:22, Patrick Bartek wrote:
> > On Sat, 22 Aug 2020 01:49:45 -0700
> > David Christensen <dpchrist@holgerdanske.com> wrote:
> >
> >> On 2020-08-21 21:02, Patrick Bartek wrote:
> >>>
> >>> Hi! All:
> >>>
> > [snip]
> >
> > Mine's the Ultra Fit, too, but 32GB. I've done some addtional research,
> > and it looks like it has wear leveling built in. > Read a SanDisk blurb
> > that all their solid state devices have it by default.
>
> AIUI all USB flash drives have wear-leveling -- it is a practical
> requirement. Otherwise, "hot spots" would wear out patches very quickly.
Wasn't always that way. Even now I wouldn't expect it on cheap "Made in
China" ones which would get lost long before they wear out. :)
>
> > In any case, the
> > NAS software I'll be using (OpenMediaVault) has a specific plugin for
> > solid state to reduce write wear to a minimum.
>
> If they've done the engineering, figured it out, and made it a plug-in,
> that sounds ideal. If you find an explanation of how they do it, please
> post a link.
I've checked the docs and nothing on what that particular plugin
actually does. OMV just recommends installing it when using flash
or ssds. Once I installed, I'll look around to see if I can find out
what it's doing.
>
> >> I used a 2015 MacBook Pro 15 with VirtualBox and a Debian desktop as a
> >> [snip]
> >>
> >>
> >> If I wanted to use a USB flash drive as a Debian system drive again, I
> >> would probably just go with an Ultra Fit 16 GB and ext4. They are
> >> inexpensive; and if they fail too often, I would try a high endurance SD
> >> card and USB adapter.
> >
> > My plan is after the OS install and configuring to just clone the drive
> > for a quick reinstall, if or when it's needed.
>
> Clones are nice. Good appliances often include backup and restore features.
Haven't gotten that far into the docs which are poor to say the least.
>
> >> Tuning the system to minimize flash drive writes sounds appealing, but I
> >> never had much success at it. Mounting the root filesystem with
> >> 'relatime' or 'noatime' options sounds like a good way to break things,
> >> and I'm not going to audit an entire Debian system to figure it out. I
> >> tried running without swap -- that is a good way to crash your systems.
> >> I have not tried alternate filesystems, because I want to be able to
> >> boot a standard Debian Installer and run the rescue console when needed
> >> (thus precluding ZFS, which I really want). One trick I have not tried
> >> is a USB disk on module. Eventually SSD's became cheap enough that I
> >> replaced all of the USB flash drives, so I have not pursued this.
> >
> > I'll use "relatime" instead of "noatime." "Relatime" is said to
> > create less problems with software that needs dates/times when files,
> > etc. were last modified, accessed, etc.
>
> I only use 'relatime' on data disks. I would not use it on a root
> filesystem. /boot might be okay. (I let the installer set the boot,
> swap, and root entries in fstab and I am loath to touch them.)
We'll see if "relatime" proves bad for / since, except for swap, it will
be the only partition on the system drive. This old box doesn't support
UEFI/GPT.
>
> > My systems rarely use swap, and when they does it's only a few
> > kilobytes. My main 1-year old under-the-desk box with 16GB RAM has
> > yet to use any.
>
> Run from RAM is definitely the best situation.
>
> [snip]
>
>
> > OpenMediaVault, to its credit, is very lightweight and
> > RAM efficient. Perfect for the home NAS on an old system.
>
> I have mixed feelings about pre-rolled appliance distributions. If I
> can fumble my way through the UI and solve my needs without
> understanding what is going on under the hood, okay. I did this with
> IPCop for years. (And, it was simple enough that I could mess around
> under the hood.) But, when I tried to make changes and understand what
> was going on under the hood of FreeNAS, it was a disaster. I started
> over with FreeBSD RELEASE and rolled my own.
I initially thought of rolling my own, too, just for the learning
experience, but OMV would save so much time and seems very
configurable. And it is open source. Uses Debian as its OS.
B
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