Re: experiences running btrfs on external USB disks?

["Austin S. Hemmelgarn" <ahferroin7@gmail.com>]

On 2018-12-04 08:37, Graham Cobb wrote:
> On 04/12/2018 12:38, Austin S. Hemmelgarn wrote:
>> In short, USB is _crap_ for fixed storage, don't use it like that, even
>> if you are using filesystems which don't appear to complain.
> 
> That's useful advice, thanks.
> 
> Do you (or anyone else) have any experience of using btrfs over iSCSI? I
> was thinking about this for three different use cases:
> 
> 1) Giving my workstation a data disk that is actually a partition on a
> server -- keeping all the data on the big disks on the server and
> reducing power consumption (just a small boot SSD in the workstation).
> 
> 2) Splitting a btrfs RAID1 between a local disk and a remote iSCSI
> mirror to provide  redundancy without putting more disks in the local
> system. Of course, this would mean that one of the RAID1 copies would
> have higher latency than the other.
> 
> 3) Like case 1 but actually exposing an LVM logical volume from the
> server using iSCSI, rather than a simple disk partition. I would then
> put both encryption and RAID running on the server below that logical
> volume.
> 
> NBD could also be an alternative to iSCSI in these cases as well.
> 
> Any thoughts?
I've not run it over iSCSI (I tend to avoid that overly-complicated 
mess), but I have done it over NBD and ATAoE, as well as some more 
exotic arrangements, and it's really not too bad.  The important part is 
making sure your block layer and all the stuff under it are reliable, 
and USB is not.