Originally Posted by tashirosgt
The Guides&Solutions section of the forum has a useful guide to using solid state drives in Fedora (http://forums.fedoraforum.org/showthread.php?t=277082
) once you have a running system installed. I'm trying the visualize the most efficient method for installing Fedora on a system with an SSD from scratch. What is the order of operations?
A/ Go ahead and partition & install, aligning the partitions
B/ After booting the new system, edit the /etc/fstab adding 'discard
' options (or more) on all the mountable partitions (swap takes care of itself).
C/ reboot and verify the mount options [look at the output of "mount" or "mount | grep discard".
D/ Run the 'fstrim'
command on the mounted file systems.
E/ everything else. The elevator=noop is a microscopic improvement. 'noatime' really cuts down on accesses but it can wait till day2 moving the /var /tmp to other partitions isn't so awful that you can't configure it after the first week.
The most critical issues are a/ partition alignment, b/ getting 'discard' mount option running and c/ 'fstrim' -ing any cruft left after the install. The other items are optional and can wait.
Perhaps people can offer some criticisms of how I think about this (since I haven't tried it yet).
I assume installing from the live CD is still a good way. I assume its not good to select the default partitioning scheme. I don't know whether using LVM is a good idea. Some of the configurations mentioned in the guide involve setting options in the /etc/ fstab file. I assume you can't do that until you do the installation and have an /etc/fstab file.
Personally I boot a live CD and use gparted to create the partitions properly aligned. Then I use gparted to create the file systems and swap with labels. Then later during a DVD install I just spec the paritions to use for /, /home and swap. At this point in history I would also run gdisk to create a mirror GUID and a 2MB BIOS partition.
You can do similar from the 'disk druid' in the DVD installer. The live CD install is more limited in options, but so long as the partitions are aligned on big-boundaries you are fine.
Whether you use LVM or not is not
dependent on the SSD drive. My *opinion
* is that few end-users ever need LVMs features, and it imposes limitations and a small performance penalty. I don't use it, even on my soho server. In the near future we will be using btrfs and dropping LVM I think. Btrfs has similar functional features as LVM built in, plus more.
One technique mentioned in the guide is to put the /var/log filesystem on a conventional hard drive, if the system has one. Should I do this in the custom partitioning phase of installation from the live CD? (I've never used that interface, so I don't know what can be done with it. I assume it lets me run fdisk.)
It's very easy to do this after the install - so I'd wait until you have all the other stuff working.
Make a partition, add it to /etc/fstab with /var/log as the mountpoint, reboot.
I'm curious what other directories could be advantageously mounted on a spinning disk. (I plan to have a laptop drive as my spinning disk.)
The rule is - if you write the directories A LOT (wear) or if you don't care if the content access is relatively slow - then move it to a spinning disk. For example your music & vid collection don't require superb speed. You might try putting all of /var on a rotating disk - those yum caches and logs under /var are huge and only used occasionally.
The general way I visualize the installation from the live CD is that you would do a custom partitioning. You would then do the "copy Fedora to hard drive" phase in the normal way. Then you would do further customization before installing addtiional packages or updating.
Yes, thats good, it's the way I would do it, but it's not that critical. It seems marginally better to get the 'discard' mount option working and the fstrim accomplished before starting any serious work.
Just for example when you "yum install" a package it loads an rpm file and installs the contents and creates a bunch of working tmp files and then it deletes the tmp files and rpm. If you have 'discard' working then the deleted file blocks become re-usable by the SSD. If you don't have discard working, then the blocks can't be reused until your disk gets filled, crufty & slow or until you run 'fstrim'.
So long as the disk has extra 'virgin' space - then installing all the packages etc, then later fixing 'discard' then running fstrim is OK.
---------- Post added at 08:30 PM ---------- Previous post was at 08:26 PM ----------
sudo fstrim /
sudo fstrim /home
sudo fstrim /other/mount/point