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Re: [LUG] Using mv command

 
On 28/10/18 19:41, mr meowski wrote:
> On 28/10/2018 18:52, M. J. Everitt wrote:
>> ^ Last para especially .. you can do some surprisingly silly things with
>> shell/parameter/bash expansions, and mis-chosen command options!
>>
>> Equally applicable to sed/awk scripts .. no harm whatsoever in making an
>> exact copy with a '.orig' or '.bak' extension, and if you make a mistake,
>> you can always get back to a 'known state'!!
>
> ZFS is genuinely changing the way I use computers now I'm fully immersed 
> in it - it has answers to everything when you really start to understand 
> it and integrate it into your workflow. For example, like Rich's 
> original problem it's pretty common for all of us to need to do similar 
> stuff, often frequently and sometimes on a _lot_ of data. Usually very 
> important data, frequently not at rest. No more lengthy recursive copies 
> or tedious testing on laboriously spun-up and snapshotted test VMs.
>
> Presume there is a massive directory of stuff at /export/private/pics 
> that needs extensive potentially destructive transformations done on it 
> - in my case /export/private/pics is a zfs dataset instead of a normal 
> ext4 folder.
>
> zfs snapshot export/private/pics@reorganizationtesting
> zfs clone export/private/pics@reorganizationtesting export/TESTING
> * do anything you want to the data here *
> zfs promote export/TESTING
>
> ZFS will take care of everything else including mountpoints, endpoint 
> re/creation, etc. Data is safe and atomically checkpointed all the way 
> through and it's CoW on course so basically instant and nearly "free". 
> Once you've checked your work is ok the zfs promote command 
> transparently moves the new data versions over the originals (and then 
> you can either keep or wipe any of the multiple snapshots and original 
> datasets you went through). You can even do this with your root 
> filesystem (although not the promote whilst it's live - yet).
>
> The coolest thing is that I zfs send/receive my main workstation and 
> laptop continuously and incrementally to a backup server: I can SSH to 
> the server, zfs clone my latest entire workstation filesystem to a test 
> dataset and then systemd-nspawn it up like a supercharged chroot. You 
> can test potentially catastrophic experiments, dist-upgrades and 
> anything else effectively instantly and free :]
>
> Cheers
>
>
Yes, I met ZFS when I tried out a FreeNAS box for my last employer. Worked
pretty nice, and the regular snapshots made backups, and restore, a
complete breeze.

I've yet to implement on my Linux systems, but as support and maturity
grows, I shall have little hesitation to run with it again, and enjoy all
the benefits it has. I don't believe there is any other FS around with such
a feature-set as ZFS although various people rave about btrfs, xfs, etc etc...

MJE

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