Jump to content
RESET Forums (homeservershow.com)

Can you install an O/S on a MicroSD card.


elvorfin
 Share

Recommended Posts

I just think there would be too much IO activity on an SD card.

 

Agreed. They're not built for it. Interestingly though, there is a Compact Flash card that is built to have an OS installed on it, even Windows. It's basically an SSD in a Compact Flash jacket. It's used primarily for embedded systems.

Link to comment
Share on other sites

Yes you can very easy. In my both my HP Microserver Gen8 I have a MicroSD (4GB and 16GB) with a fully functional Fedora 20 Live for system rescue purposes.

 The installation is very easy just follow the https://fedoraproject.org/wiki/How_to_create_and_use_Live_USB. There is no diference between a MicroSD and a USB drive from this point of view.

  Even a 4GB MicroSD is enough, 2GB can be too small.

Link to comment
Share on other sites

For those purposes, georgio, it works really well. jmwills & I are just saying not to run an OS like Windows on it. I might run the WHS2011 install ISO from one, particularly to Restore the OS from a backup.

 

And agreed, there is no difference between an SD and USB drive.

Link to comment
Share on other sites

  • 10 months later...

Hi

I am currently using my gen 8 booting direct to Xpenology on a USB 2 flashdrive, I thought it might be quicker on a USB 3.0 but it wouldnt boot.

I wonder if it would be any speed improvement with class 10 micro sdcard. and what I would have to do to change to that is so.

many thanks

K

Link to comment
Share on other sites

The biggest problem with running an OS from an SD card isn't that it will wear out too quickly - I run various ARM machines off SD cards and I have yet to have one expire as a consequence. By far the biggest problem is performance. Random write performance of an SD card is typically 1-5% of a low end mechanical SATA drive. Some SD cards are much better than others, but there is no distinct pattern to which ones - one model of one brand might be good, another model of the same brand might be attrocious.

 

There are some workarounds for this:

 

1.1) nilfs2

Pros: This file system is log-structured (append only), which means all writes are always sequential. Since SD cards are good at sequential writes, the performance is generally quite good.

Cons: The way space is reclaimed is that a chaser thread reaps the oldest written data, prunes out deleted data, and re-writes the remaining data to the head of the device. That means that a lot of data writed happen needlessly, causing potentially large anmount of write amplification and increased flash wear over time.

 

1.2) ZFS

If you use ashift=13 (8KB sectors) and sync=disabled, the performance with ZFS is reasonably bearable. This is what I use on all of my ARM devices.

 

3) Put /tmp, /var/tmp, most things under /var/cache and similar on tmpfs

 

It all merely helps make the most of a very raw deal, but it makes SD performance bearable. In general most of what hits the rootfs on a typical server is logging. As long as this isn't too heavy, and all of your heavy I/O is happening on real disks, it will probably be OK.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...