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strategy for installing *Nixes externally

Posted: Wed Nov 18, 2009 1:28 am
by nweissma
a thousand apologies if this post has been improperly placed -- admins: pls move as per your opinion.

to wit:

c:\ ,1TB, primary hdd, holds vista 32. a previous bad episode with ubuntu installation on internal, vacant D:\, tsunamied my computer, so I will be sure to physically disengage C: before I attempt any type of os installation.

This time, there is no internal D: but rather an external dual bay JBOD, now populated with two identical hdd's. My aim is to install several *Nix'es -- Mandriva, Fedora, FreeBSD -- onto the 2 JBOD hdd's, so that I can choose which os will boot at power up, and be able to change the os without the need to power down.

It appears to me that I have several options: I can use a virtual machine; I can use the likes of Acronis Disk Director Suite http://www.acronis.com/company/inpress/ ... ctor.html; and I can use the strategy delineated by Ozar (above, which I don't fully understand so it may be the Linux equivalent of the acronis software.) Additional options are gratefully solicited.


The first issue is deciding whether I should use the JBOD mode (the two hdd's are seen as 2 separate hdd's) or use the BIG mode (both hdd's are seen as a single one with the summed capacity). Next issue is whether to configure in spanned, simple or striped mode. Thus, at the first juncture, I am faced with 6 permutations: JBOD/simple; JBOD/spanning; JBOD/striped; BIG/simple; BIG/spanning; and BIG/striped. (I can't understand the difference between, eg, JBOD/spanning and BIG/simple! I feel like a sophomore in my first second organic chemistry class: no clue!)

Another issue is whether I should abandon the JBOD hardware in favor of adding D: internal and then partitioning C: and D:

and one further issue (as ridiculous as it may appear): exactly where should these softwares -- bootloaders, partitioning, .. -- be installed? on c:? one of the jbods? both of the jbods?

Re: strategy for installing *Nixes externally

Posted: Wed Nov 18, 2009 1:41 am
by just brew it!
Is this external enclosure USB or eSATA? Using USB for your system drive is not a good idea. If you're trying to do any sort of real work on this system, using USB for the system drive will bottleneck system performance rather severely.

Re: strategy for installing *Nixes externally

Posted: Wed Nov 18, 2009 1:48 am
by nweissma
the external dual-bay jbod is usb. why is usb for a system drive a bad idea-- i understand that *nix'es require only small speeds?

Re: strategy for installing *Nixes externally

Posted: Wed Nov 18, 2009 2:11 am
by just brew it!
The bandwidth of USB is lousy, and disk I/O will also tend to load the CPU fairly severely. You also lose the ability to do NCQ (which may or may not matter, depending on what you're doing). The restricted bandwidth and high CPU demands of USB will combine to drag down the performance of the system. Possibly by quite a lot. External USB drives are really suitable only for storing files where you don't care too much about access speed (e.g. your media library), or for backing up the contents of your internal drives.

I'm not sure where you heard that hardware performance doesn't matter for *NIX. Yeah, if you're running a stripped-down distro like Knoppix or Damn Small Linux, or doing command-line only (no GUI), you can get away with some pretty low-spec hardware. But full-blown contemporary desktop Linux distros like Fedora will have similar hardware requirements to Windows.

Edit: Just so we're clear here... yeah, Linux can run from an external USB drive. But expect performance to be on par with a system from a few generations back. And if you start hitting the pagefile at all, it'll be hopelessly slow.