Questions about installation on SSD

peoro · 2012-04-28 21:00:45

Hello,

I'm going to buy an SSD (a 120GB OCZ Vertex Plus) to replace the HDD of a laptop I'm going to buy...

Latelay I read a lot about this technology, but still have a lot of questions:

Partitions
On this forum people suggests to divide SSD in several partitions (one for /boot, one for /var, one for /home and so on). Why is that?
I would think that dividing the system in a number of partitions should give less benefits to an SSD compared to an HDD due to the lower random access times. Am I wrong?
Besides if one partition (say /var) is written more than other partitions (say /boot), the SSD blocks where the first partition is allocated will wear out sooner than the other blocks. Using a single 120GB partition for the whole system should level out the SSD cells wearing and this should be a good thing...
Filesystems
On my EeePC's disk and on occasional flash drives I used to install Arch on a NILFS2 filesystem. The SSD I'm going to buy supports TRIM, so I think that any filesystem supporting TRIM will be just as good. Am I right about it?
On the Wiki the two filesystems suggested for SSDs are ext4 and btrfs. I never used btrfs and what I found on the internet didn't help me much in deciding which one to chose. I'd love to hear some impressions on this topic...
Usage info
Is there any tool to get some info about the disk I'm going to buy, and its status?
Things like the page and block size, whether TRIM actually is enabled, how many cells are dead, the number of write cycles, the total amount of data read and written ...
IO scheduler
I'm planning to use noop as IO scheduler. Passing it as a kernel parameter looks like the best solution to me. What would happen then if I plug in an USB HDD? Will I need to change the IO scheduler fur such device?
Anyway shouldn't it be udev to choose the scheduler for the plugged drives?

graysky · 2012-04-28 21:06:00

1) https://wiki.archlinux.org/index.php/SSD
2) ext4 and btrfs
3) iotop can do some of these
4) depends on how you do it. see https://wiki.archlinux.org/index.php/Li … _Scheduler

peoro · 2012-04-30 07:07:11

graysky wrote:

1) https://wiki.archlinux.org/index.php/SSD
2) ext4 and btrfs
3) iotop can do some of these
4) depends on how you do it. see https://wiki.archlinux.org/index.php/Li … _Scheduler

Was hoping in some more detailed answers...

I already read the wiki (and a lot of other websites), but it's not very elucidating...

whaler · 2012-06-11 02:13:31

The ArchWiki article "Solid State Drives" recommends fdisk for the legacy method (MBR) to make alignments and create partitions on SSD's. However, on my system, 'man fdisk' does not show any of the parameters referenced in the article. I can find no '-o', '-n', '+xG' or 'w' parameter...?

Am I using a 'wrong' fdisk, or is it something other I don't get?

lilsirecho · 2012-06-11 05:28:08

Peoro:

IMHO your analysis is probably on target wherein you state that 120Gb for one partition is the best assignment for flash devices.

My system has a 100mb boot partition and the rest is all one partition as root. The units I use are cf cards which do not have as much size as yours but I expect a good long life because of the algorithms provided within the devices. As I understand the system, the same cells are not addressed each time a file is written which means the cells get a rest every time the file is utilized.

Good luck with your SSD. I have five pairs of CF devices bootable grub2 partitioned in Raid0.

This one is 59GB for the pair. Root only...............

Arch Linux

#1 2012-04-28 21:00:45

Questions about installation on SSD

#2 2012-04-28 21:06:00

Re: Questions about installation on SSD

#3 2012-04-30 07:07:11

Re: Questions about installation on SSD

#4 2012-06-11 02:13:31

Re: Questions about installation on SSD

#5 2012-06-11 05:28:08

Re: Questions about installation on SSD

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