recommendations for SSD drive as first disk for fedora 18?

[Bill Davidsen]

Sergio Augusto Vladisauskis wrote:
> Look this topic: http://thessdreview.com/Forums/linux/225-post2940.htm#post2940
> I using Fedora 17 with this options.
>
> PS: my logs put in other HD.
>
Always good to get another view, however I would like to see a better 
explanation of what those changes do before just telling people to do them (him, 
not you).

in no order:

deadline scheduler works for SSD (and most types of RAID) but I did't see any 
big gain so I general l don't bother.

Having /tmp be really temporary can lead to having to find a better place to put 
stuff you need for a few days, and putting it in RAM requires enough memory to 
match what you would use on disk. In my case that's a few GB, but everyone has a 
different idea of what it should do, so understand the results before you decide 
faster is always better.

I want to test what setting fifo_batch is going to do before I comment on that. 
There is no such value in RHEL5 or FC17 on my machines:
    ls -lG /sys/block/sda/queue/iosched/
    total 0
    -rw-r--r--. 1 root 4096 Jan 22 13:38 back_seek_max
    -rw-r--r--. 1 root 4096 Jan 22 13:38 back_seek_penalty
    -rw-r--r--. 1 root 4096 Jan 22 13:38 fifo_expire_async
    -rw-r--r--. 1 root 4096 Jan 22 13:38 fifo_expire_sync
    -rw-r--r--. 1 root 4096 Jan 22 13:38 group_idle
    -rw-r--r--. 1 root 4096 Jan 22 13:38 low_latency
    -rw-r--r--. 1 root 4096 Jan 22 13:38 quantum
    -rw-r--r--. 1 root 4096 Jan 22 13:38 slice_async
    -rw-r--r--. 1 root 4096 Jan 22 13:38 slice_async_rq
    -rw-r--r--. 1 root 4096 Jan 22 13:38 slice_idle
    -rw-r--r--. 1 root 4096 Jan 22 13:38 slice_sync
    -rw-r--r--. 1 root 4096 Jan 22 13:38 target_latency
so I want to go look at the kernel code and description to see what that does 
and what side effects it might have.

Changing the elevator=deadline option on the kernel command line will change it 
for all drives, not just the SSD. That may really not what you want for 
performance on non-RAID drives.

The techniques are good to know, but I hope people do understand the side 
effects of some of these things.

-- 
Bill Davidsen <davidsen at tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot