In questa semplice guida vedremo come attivare Trim nelle nostre SSD con installato Ubuntu Linux o una derivata
Le SSD o Unità a Stato Solido sono presenti ormai in molti nuovi
personal computer, molti utenti utilizzando le SSD per velocizzare il
proprio sistema (visto anche il costo ormai molto abbordabile) incidendo non solo sulle performance ma anche nell'autonomia dei pc portatili.
Tra le novità incluse in Ubuntu 14.04 Trusty LTS troviamo l'attivazione di default di Trim su SSD
grazie al quale gli utenti che utilizzano un'unità a stato solido
noteranno una maggiore velocità di scrittura, oltre ad aumentare la
durata dalla SSD. Supportata dal gran parte delle SSD attualmente
presenti sul mercato, TRIM è un'utile tool che consente al sistema
operativo di dire all'unità quali pagine di memoria non sono più
necessarie, cosi poterle cancellarle (se opportuno).
In questa guida vedremo come attivare Trim su SSD in Ubuntu o una derivata (compreso anche Linux Mint ed elementary OS),
prima di procedere all'attivazione dovremo però verificare che la
nostra unità a stato solido supporti questa funzionalità per farlo basta
digitare da terminale:
sudo fdisk -l
il comando ci darà l'elenco delle partizioni e dei dischi presenti sul
pc, questi ultimi avranno un nome del tipo sdx (ad esempio: sda, sdb,
sdc..), una volta individuato il nome della nostra SSD (esempio sda)
dovremo digitare:
sudo hdparm -I /dev/sdxx
dove al posto di sdxx dovremo inserire il nome della nostra SSD per sda dovremo digitare:
sudo hdparm -I /dev/sda
se supportata dovremo avere come risultato "Data Set Management TRIM supported" come da immagine sotto
Attenzione: Trim supporta solo Ext4 e Btrfs non funziona ad esempio con Ext3 o altro file system
Una volta verificato per abilitare Trim sulla nostra SSD dovremo operare
sul file /etc/fstab per prima cosa ci facciamo un backup del file in
modo tale da poterlo ripristinare in un secondo momento per farlo basta
digitare:
sudo cp /etc/fstab /opt/fstab.back
a questo punto avviamo /etc/fstab con nano digitando:
Adding a solid-state drive (SSD) to your computer is simply the best upgrade at your disposal,
capable of speeding up your computer in ways you hadn't thought
possible. But as with any new technology, there's plenty to learn.
Here's everything you should know about your SSD, whether you're
interested in upgrading or just like to know the ins and outs of your
hardware.
Blast from the past
is a new weekly feature at Lifehacker, in which we revive old, but
still relevant, posts for your reading and hacking pleasure. This week,
we're updating our complete guide to solid-state drives, making it
easier than ever to find everything you need to know about the best
upgrade you can make.
What Is a Solid-State Drive (SSD)?
Expand
A
solid-state drive (SSD) is a data storage device for your computer. In
everyday use, it provides the same functionality as a traditional hard
disk drive (HDD)—the standard for computer storage for many years. In
fact, you wouldn't even know whether you're using an SSD or HDD if it
wasn't for the differences in how they operate. HDDs store their data on
spinning metal platters, and whenever your computer wants to access
some of that data a little needle-like component (called the "head")
moves to the data's position and provides it to the computer. Writing
data to a HDD works in a similar fashion, where parts are constantly
moving. SSDs, on the other hand, don't move at all. They store their
data in blocks. When the computer wants some of that data, the SSD just
says "okay, here it is." This is a simplified explanation, of course,
but you might have noticed that the SSD's process seems a bit more
direct and efficient. It is, and speed is the primary advantage of an
SSD over a traditional HDD. This makes an SSD the single best upgrade
for your computer if you're looking for a way to make it operate faster.
A new SSD can speed up your computer in several ways:
Boot times will be significantly reduced.
Launching applications will occur in a near-instant.
Saving and opening documents won't lag.
File copying and duplication speeds will improve.
Overall, your system will feel much snappier.
SSDs have
their downsides, however. For starters, an SSD won't hold as much data
per dollar as an HDD. For the same $100, you could buy either a 120GB
SSD or a 2TB HDD. That means you're paying around 83 cents for every
gigabyte on an SSD versus five cents for every gigabyte on your HDD.
That's a huge difference in cost, and the gap only grows as you compare
larger drives. Luckily, it's not an all or nothing proposition. In the
days of cloud storage and streaming media, SSDs provide plenty of space
for most people. For those who need more storage than is affordable with
an SSD, SSDs and HDDs can coexist on the same system (and we'll discuss
those in depth a bit later), so you can enjoy the speed benefits of an
SSD without sacrificing on storage.
In this
post, we're going to walk you through everything you need to know about
getting started with your first solid-state drive, from buying the one
that suits you best to getting it set up and running most efficiently in
your computer. We'll even take a look at a few advanced techniques for
those of you who are ready to do even more with your super-fast storage
device.
How to Choose the Right SSD
Choosing
the right solid-state drive for you isn't difficult, but the process can
be a little overwhelming with so many brands available. In this
section, we'll show you what you want to look for when choosing a drive
and offer up a few recommendations that have worked well for us.
All SSDs
are fast, and will feel like a great upgrade from a HDD, but when you're
spending significantly more money on a drive that provides less storage
you want it to be one of the best. You also want a reliably piece of
hardware, and these are both fairly hard to gauge if you have little
experience with the technology. Here are the qualities you want to look
for in an SSD when you're shopping around:
Expand
High maximum speeds: Max read speeds are around 400MB/second, and max write speeds are around 300MB/sec (note: that's megabytes per second). These numbers do not have to be exact. A little faster or slower won't make a significant difference.
Good real-world speeds:
The SSD manufacturers generally will not provide real-world read and
write speeds, as they're guaranteed to be slower than the maximums.
Fortunately, many online reviews contain speed test results. On Amazon, you can often find users who've posted screenshots of their test results (here's an example).
Seeing this data can often be discouraging because the real-world rates
are quite a bit lower. If the test results reveal read and write speeds
of about 2/3 of the maximum (in the sequential and 512KB block tests)
you're good to go. If you apply this to our maximum speeds above, that
comes out to read speeds of about 265MB/sec and write speeds of about
200MB/sec. If you want to figure out if a more expensive SSD is worth
the money, its real-world test speeds will be higher than 2/3 of its
reported maximum capabilities.
Multi-Level Cell (MLC) NAND flash memory:
When shopping for SSDs, you'll run into two kind of memory: multi-level
cell (MLC) and single-level cell (SLC). The primary difference is that
MLC memory can store more information on each cell. The advantage here
is that it is cheaper to produce, and SLC is often cost-prohibitive for
the average consumer. The downside is a higher rate of error, but an SSD
with error-correcting code (we'll discuss this momentarily) can help
prevent these problems. (You can read more about MLC here.)
SATA III Support:
Most SSDs use the Serial ATA (SATA) interface, but not all use the
latest version and this can limit the performance of your SSD. This is
because SATA I can transfer data at 1.5 Gbps, SATA II at 3.0 Gbps, and
SATA III at 6 Gbps. To ensure your SSD has enough bandwidth to transfer
data as quickly as possible, you want it to be compatible with SATA III.
You'll also want to make sure your computer is SATA III compatible as
well. If not, SATA III-capable drives will still work as all versions of
SATA are backwards-compatible. Just know that you may not get the most
out of your SSD if your computer doesn't support the most recent SATA
specification.
ECC memory:
Error-correcting code (ECC) memory does what the name implies: it
provides your SSD with the ability to detect and correct common types of
data corruption so you don't end up with unusable data on your drive.
An SSD with ECC memory is more reliable. (You can read more about ECC
memory here.)
A history of reliability:
Reliability is a very hard thing to gauge, but there are a few tricks
you can employ to get a good idea. First, look for an SSD that is made
by a manufacturer who has been in the business for a while (I like OCZ
and Crucial). The technology is fairly new, so you don't want to go with
just any company who has recently decided to jump on the solid-state
bandwagon. Additionally, look at the rating each SSD receives in online
shopping reviews. If it is rated a 3.5 out of 5.0 or higher, this is
often points to a reliable drive. When the ratings are lower, you may
want to look elsewhere. Even reliable companies make unreliable SSDs
sometimes, so keep an eye on reviews to avoid buying a lemon.
Which SSDs meet these criteria? This changes over time, so we're going to defer to our friends at the Wirecutter,
who will keep their SSD buying guide up to date as things change. It's
not an end-all-be-all suggestion, so if you want to shop around and
weigh your options, keeping the criteria mentioned in this section in
mind will help you find a good, reliable drive.
How to Install Your SSD
Installing
your SSD will be different depending on your computer, so we highly
recommend looking up a guide for your specific model of laptop or
desktop. That said, if you have a desktop, our guide on building a computer should at least steer you in the right direction.
More
important is figuring out where all your data will go. Most HDD owners
are accustomed to having at least 500GB of storage, if not upwards of
2TB. Downsizing to 120GB or 240GB—the most affordable and popular SSD
sizes—can be a tough job. If you're using a desktop, you can use your
SSD for your operating system and another hard drive for your data. If
you're using a laptop, you can either try to fit everything on the SSD,
or use an external drive for the data that won't fit (like music and
movies).
Once you've figured out a plan, it's time to actually switch to the SSD. Here are your two options for doing so:
Option One: Start Fresh and Copy the Essentials
Expand
When
upgrading to an SSD, the most obvious option is starting fresh with a
new install of your operating system. While this might require a little
more of your time, you'll have everything configured perfectly when
you're done. Here are the steps you need to follow:
Install your operating system of choice on the new SSD.
Copy the
contents of your home folder from your previous HDD to your new SSD. If
you can't fit everything, start with the essential system files and
settings, then migrate the media you have room for.
Go
through the list of applications on your old HDD and install them on
your new SSD. Run any updates, or save yourself some time by downloading
the latest versions from their respective sources. Windows and Linux
users can employ Ninite
to get the latest versions of popular free software titles for their
machines. OS X users can head to the Mac App Store to download the
latest versions of their previous purchases.
Copy any important documents (or other files) you have room for on your SSD.
Put the old HDD in an external enclosure (like these),
if you haven't already, and keep it handy for a month or two. This will
help you see what files you use often and which ones you don't. If you
find you're using something often, copy it to the SSD. If not, leave it
on the external HDD for occasional access.
Again, this
method requires more work but also handles the task of cleaning up your
system at the same time. It may be more tedious, but it is an efficient
way to solve two problems at once.
Option Two: Migrate Your Data from Your Old Hard Drive
Expand
If you
don't want to start with a fresh installation of your operating system,
you can always migrate your OS (and other data) to your new SSD. Chances
are, however, that you're not going to be able to fit everything. That
means you're going to have to start deleting files on your main drive
until it is small enough to fit on your SSD. Because you don't want to
lose that data forever, start by making a backup of your drive. Once you
have a complete backup, you're ready to get started.
Windows users can follow our SSD migration guide
for the complete instructions. It comes across as a complex process,
but shouldn't take too much time. You also won't have to reinstall
Windows. Mac users can follow our MacBook SSD installation guide.
While the guide focuses on installing an SSD in a MacBook Pro's optical
disc drive bay, if you skip to the second half you'll find instructions
on performing a data migration as well.
If You Don't Have a Second Hard Drive: Use an External Drive and the Cloud to Combat Storage Constraints
Expand
Regardless
of the size of your SSD, it's never going to beat the storage capacity
of a HDD. If you don't have a secondary hard drive installed in your
computer, you're going to need to store your excess data elsewhere. An
external HDD and the cloud are two of the best ways to get around the
storage limitations of your SSD.
Unless you
have enormous collections, an SSD with a 240GB (or higher) capacity
should be able house your operating system, documents, music, and photos
without issue. It's when you get into the business of music creation,
video editing, professional photography, and other work that produces
large files will you regularly run into a storage ceiling. An external
drive is often the easiest solution, so you'll want to pick up one with a
large-enough capacity to suit your needs. If you're looking for a
portable drive, the Seagate GoFlex series
is worth a look as it not only works with USB 3.0, but can be connected
to other ports like Firewire 800 and Thunderbolt by way of adapter.
This also provides you with some assurance of compatibility with future
technology.
When an
external drive won't do the trick, and you really need to downsize your
space-hungry media collection, the cloud can come to the rescue. Most of
the best solutions come from Google because they're both simple and
free. Google Play Music
allows you to upload your entire audio collection, and doing so will
allow you to delete any songs you rarely listen to (or at least move
them to an archival hard drive) while still maintaining direct access to
them from anywhere you have an internet connection. Picasa can do the same thing for your photos. (Personally, I prefer Flickr, but it isn't free.) When it comes to other data, you have plenty of options. Google Drive is great for various files, Simplenote for text, and Evernote
for rich text and PDFs. It doesn't matter so much which services you
use, but rather that you start making regular use of the cloud if you
have heavy data needs that can't be adequately served by an external or
secondary internal drive.
Optimize Your SSD for Optimal Performance
For the
most part, there isn't much you have to do to optimize your SSD. It's
already really fast and should do it's job without any adjustment. That
said, you can achieve better performance and longevity with a few
adjustments.
Enable TRIM
Expand
The very first thing you should do after installing and setting up your SSD is enable TRIM. What is TRIM, exactly? Wikipedia offers a concise explanation:
TRIM is a
command [that] allows an operating system to inform a solid-state drive
(SSD) which blocks of data are no longer considered in use and can be
wiped internally.
Basically,
it prevents your SSD from being overused. Just like any component, SSDs
have limited lifespans. TRIM helps keep your solid-state disk alive a
bit longer, so you want to have it enabled if your drive supports it.
Here are instructions on how to find out and enable TRIM in Windows and OS X.
Don't Defragment Your SSD
When data
is stored on a drive, it often ends up in various parts that aren't all
in the same place. This is called data fragmentation. It slows down HDDs
because the drive's head needs to move from place to place to read all
the little bits of information. This can be fixed using a process called
defragmentation, which is built into recent versions of Windows (7 and
higher) and OS X. Because the location of data on an SSD is pretty much
irrelevant, as it can quickly access any of it regardless of where it
is, defragging a SSD is not only unnecessary but bad for the drive as
well. SSDs have a limited lifespan that's determined by how much they're
used. While most will last as long as you'd ever need, defragmenting
the disk involves reading and writing data unnecessarily and those
actions will shorten your SSD's lifespan. OS X and Windows should know
when you're using an SSD and turn off defragmenation automatically. That
said, it's important to remember not to defragment your solid-state drive. It provides no real benefit and can shorten its life.
For more tricks on getting the most from your SSD, check out our guide to taking full advantage of its speed. Now that you have an SSD, certain things—like Hibernation—are much faster than they once were, and are really worth using.
You should
now be well on your way to a better, faster computer with your
solid-state drive. Most of us here at Lifehacker have been enjoying the
benefits of SSDs for a few years now and can't imagine going back to a
traditional hard drive. Despite the limitations and the cost, they're
one of the best investments you can make. We hope you enjoy your SSD as
much as we're enjoying ours!
Nei giorni scorsi abbiamo visto come è semplice passare Arch Linux da un normale hard disk in una SSD utilizzando l'installer di Arch Linux.
Alcuni lettori ci hanno chiesto se possibile fare tutto questo anche con Ubuntu, copiare l'intera distribuzione in un'altra partizione su SSD e ripristinare il boot correggendo fstab.
Incuriosito ho ripreso il mio nuovo SSD formattato e ho provato a passare al suo interno Ubuntu 12.10 presente nel mio pc desktop "muletto".
Per far tutto questo ho deciso di utilizzare l'installer di Arch Linux
per il semplice fatto che con genfstab ho già fstab corretto e
funzionante senza doverlo riscrivere da nuovo (magari come spesso accade
sbagliando qualche dato).
Passare Ubuntu da un normale hard disk a SSD è molto semplice, ecco come ho fatto:
Per prima cosa dobbiamo collegare SSD al pc mantenendo collegato anche
l'hard disk con Ubuntu e avviamo dal boot l'installer di Arch Linux.
Una volta avviato impostiamo la tastiera italiana digitando:
loadkeys it
fatto questo digitiamo
fdisk -l
per verificare come viene riconosciuto il nuovo SSD dal sistema (nel mio vaso sdc)
fatto questo creiamo una partizione di root e una di swap con cfdisk basta digitare:
cfdisk /dev/sdc
nel mio caso ho creato una partizione da 30 Gb di Root (sdc1) e una da 2 Gb di Swap (sdc2)
una volta create le 2 partizioni dovremo formattarle digitando:
mkfs.ext4 /dev/sdc1 mkswap /dev/sdc2
a questo possiamo copiare Ubuntu nel SSD digitando:
dd if=/dev/sda1 of=/dev/sdc1
al termine dovremo ricreare il fstab e aggiornare il grub altrimenti non
potrà avviarsi per far tutto questo basta montare la nuova partizione
con Ubuntu e la swap:
mount /dev/sdc1 /mnt swapon /dev/sdc2
e generiamo un nuovo Fstab (importante) digitando:
genfstab -U -p /mnt | sed 's/rw,relatime,data=ordered/defaults,relatime/' >> /mnt/etc/fstab
ed entriamo nel nuovo sistema operativo utilizzando Chroot digitando:
arch-chroot /mnt
e aggiorniamo il boot digitando:
update-grub
al termine digitiamo exit e riavviamo.
Al boot accediamo dalla nuova partizione sdc e dovremo avere Ubuntu su SSD veloce e scattante.
