optimal(?) layout of fedora 19 with one SSD drive and one regular HD?

[Robert P. J. Day]

Quoting Roberto Ragusa <mail at robertoragusa.it>:

> On 12/02/2013 10:30 AM, Robert P. J. Day wrote:
>>   i'm about to install f19 new on an ASUS G74S laptop with:
>>
>> * primary 240G SSD drive
>> * secondary 750G regular HD
>>
>> as well as 16G RAM
>
> I have been running a similar configuration for 18 months
> on a laptop (256GB, 500GB, 16GB).
>
>>   as i see i, first, if i want LVM, i want to restrict it to the
>> second drive. i don't see much value in LVM on the SSD, and i
>> certainly don't want to have a single volume group spanning both
>> drives as that just gives LVM the opportunity to create LVs mixing
>> SSD and non-SSD PVs, and i'm pretty sure i want to avoid that.
>
> Even with a single VG on both drives, you can specify where
> your LVs must go. And you can move them in any moment (pvmove).

   ah, and you can do this at *installation* time in fedora 19? in
all honesty, i was teaching a first-level RH admin class last
week and one of the students had had some experience with the
installation program for f19 and he was utterly unimpressed --
said it was massively non-intuitive compared to previous versions
and after playing with it, i'm tempted to agree.

   that said, i might still be tempted to go with two VGs -- one
for "system" (OS), the other "data" (/home, etc.), since i'd
probably want to mess with them independently.
>
>>   so, as a first impression, i'm tempted to partition the SSD
>> drive using standard partitions:
>>
>> * small /dev/sda1 for /boot
>
> Ok.
>
>> * another small regular partition for swap?
>
> Not too small. Go for 25GB, so you can suspend to disk at SSD speeds.

   i have 16G of RAM and, if memory serves (which it might not), i
think i *rarely* have to resort to swap given that much RAM. if i
was using swap constantly, i'd probably put it on the regular HD,
but in this case, yes, putting it on SSD would make more sense
under the assumption that i'd rarely need it except for
suspend.
>
>> * remainder for root partition, with the understanding that anything
>> under root that represents constant activity will be partitioned
>> off to the secondary drive.
>
> Basic consideration: if there is constant activity, it IS well
> suited to the SSD. Do you want to use your SSD or just keep it
> there doing nothing while the disk works?
>
> The paranoia about SSD wearing out is exaggerated.
> It can die, ok, but every disk can die. Just backup regularly.

   another possibly dumb question since this is my first foray into
SSDs -- is there a utility that will show me current wear levels?
i suspect you're right -- i'll probably wear out the laptop before
i wear out the SSD.
>
>>   so what goes on the second drive? i'd turn it into one PV, and
>> define a single VG based on that, then define a number of LVs,
>> the biggest one being /home, perhaps 500G. but what else deserves
>> to be an LV? i might create a /srv LV for serving content, but what
>> about things like /tmp, /var, /run, etc. some are of type tmpfs,
>> what should i do with those? if they run totally out of RAM, then
>> i don't care. in short, / and /boot aside, what other top-level
>> directories merit their own LV on the second drive?
>
> I think /home should be on the SSD (do you want a fast grep
> in your files?)
> And /tmp and /run are already tmpfs based.
> And I don't see a point in relegating just /var to the disk.
>
> My approach has been: everything on the SSD, with the HD being
> just a big data repository of big and infrequently accessed files
> (media stuff, isos, ...), as a sort of "external disk" which is
> always available.
>
>>   and, finally, can i do all of this at install time? i suspect so,
>> just want to make sure.
>
> Of course you can.

   ok, i'll keep reading. i see a couple more responses to my query,
i'll get to those shortly.

rday