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Spanned volume

Posted: Fri Nov 04, 2016 9:23 pm
by Spektro
Hello,
Would it be possible to implement a system where identically named partitions that located on different hard drives automatically formed a spanned volume, appearing as a single large volume. It would be really easy for the user to create a large volume, for example for backups.

Re: Spanned volume

Posted: Fri Nov 04, 2016 10:52 pm
by colinw
I think someone wrote a RAID-0 driver or software solution for this, that's what you are after.
I'm not sure if there are also Amiga RAID-1+ options.

Here's some reading material; http://en.wikipedia.org/wiki/RAID

Re: Spanned volume

Posted: Sat Nov 05, 2016 9:30 am
by tonyw
It would be possible, if spmeone wrote suitable software to identify and support such drives, but why would you bother? You can buy a RAID server for less money than an Amiga, it comes with full software and is accessible by other platforms as well.

I can't think of a single reason why I would want to tie up an expensive Amiga to do such a time-consuming job. Leave it to the x86 boards.

Re: Spanned volume

Posted: Sun Nov 06, 2016 12:29 am
by Spektro
Ah, RAID 0 (striping) is a better version of JBOD (spanning). I thought all RAID types were about securing your data and not concatenating disks.

Salass00 has written a software RAID (swraid.device) but it's hard to set up. You have to create an xml configuration file and mount the RAID partition. If it were simpler to use, it would be perfect.
tonyw wrote:It would be possible, if spmeone wrote suitable software to identify and support such drives, but why would you bother? You can buy a RAID server for less money than an Amiga, it comes with full software and is accessible by other platforms as well.

I can't think of a single reason why I would want to tie up an expensive Amiga to do such a time-consuming job. Leave it to the x86 boards.
Well, I'm an Amiga user and not interested in the mainstream solutions :)

Re: Spanned volume

Posted: Fri Dec 22, 2017 1:53 am
by Belxjander
I have run across a hardware option for RAID that is Amiga compliant (at least for 4.x+)…

Logitech do a “Gachabay” branded set of SATA/USB3 Harddisk RAID controllers for the Japanese market,

you can slot between 2-8 mixed disks as a single device in a simple JBOD(multiple disks by LUN)/RAID0/… arrangement.

this is letting me add 2x500GB SATA disks using a single USB port (unit0, lun0 and unit0, lun1 within Media Toolbox),
using the JBOD option and I can also set the DIPswitch config to RAID0 or RAID1 on the unit I have here.

would this be something of interest for you in solving your backup requirements as well?

I originally tested with 2x1TB drives and it let me mirror duplicate my updated system to both drives from RDB and partitioning as well as all filesystem contents (all writes are mirrored to both HDDs…)

the only issue I have with the USB3 device I have here is the vibrations off the unit when it is accessed.

when it is unplugged the drives are actively powered down (it also has active cooling)

so far I have had no issues and have found it to solve my own needs with regards making sure I don't lose anything.

Note: this is a hardware RAID solution that works transparent to the machine it is uaed with…
which kind of makes software raid a limitation of device drivers that are specifically for RAID usable disk controllers.