Pi storage

Am wondering how Pi users handle document storage, i.e on an external drive. Do you use a pen drive or an external SSD and how is it formatted?

Years ago, before the first RPi, I used a BeagleBoard with a 4GB USB stick. The stick eventually became read only. USB sticks are not made for the sort of use that a computer’s drive gets (and neither are SD cards, so I hope you aren’t using it as such – you probably won’t be for long).

For a long time now I’ve used a SanDisk 2.5" SSD in conjunction with a USB-SATA interface that I got from eBay. It’s formatted ADFS by HForm. That’s the best combination of high speed and long life that you’re going to get. This is currently with an RPi 3B+, but the same drive was used with a BBxM for a long time until I damaged the BBxM and thus had to buy the RPi as replacement.

The RPi boots off SDHC but that’s all – the SSD does all the rest.

However, if you’re just wanting a drive to store a few documents and to transfer them between systems, your best bet is a USB stick formatted FAT32.

Thanks. I’m just setting the Pi3B+ up at the moment, having previously used a “cased” Pi1 (CJE) with a 60GB SSD for the data, keeping the OS and apps on the SD card. I take it you move everything except !Boot onto the SSD?

Are there any limitations on the size of disk that RO (Direct) can handle?

I note that I can get a portable 250Gb Sandisk SSD with a USB C fitting. Presumably I would need an adapter cable but could connect it to a powered USB hub, for instance? Obviously it would need to be formatted using HForm; I assume SSDs are normally formatted as NTFS?

I take it you move everything except !Boot onto the SSD?

You can move (most of) !Boot as well.

Are there any limitations on the size of disk that RO (Direct) can handle?

Filecore limits are: 256GB for the standard block size; 2TB when using a 4kB block size.
FAT32 can be used on drives up to 2TB in size.

Of course, a 2TB SSD would cost a bob or two…

could connect it to a powered USB hub

A powered USB hub is a must-have. SSDs don’t consume huge amounts of power (one chosen at random claims a peak power consumption of 2.8W) but in general the less current you’re drawing from the Pi’s own power supply the better.

Do remember that SSDs on Pi are a bit of a, well, anti-climax due to the limitations of USB. USB 2.0 isn’t “full duplex”, so reads and writes can’t happen at the same time. This means that write performance, for example, will always be half of max, and not a lot better than SDFS. Reads will be a touch faster, but it won’t be dramatic – probably no more than about 20-25 MB/sec compared to 15 MB/sec on the SD card. In all honesty, a cheap USB hard drive will likely be just as effective, although the SSD will have faster access time, which can certainly help. Alternatively, a couple of decent SD cards (eg. Samsung or Sandisk Extreme) might be within spitting distance, performance-wise.

When you format the disc, if formatted with Hform, you’ll want to keep the size under 256 GB, although Hform should take care of that automatically. If using FAT32 format, which can mitigate the bad write speeds, you can use up to 1TB (maybe more), but you’d want to boot off SDFS to ensure FAT32 reading is soft-loaded.

In all honesty, if you’re keen to spend you might want to consider putting the money towards a more capable, full RISC OS system (faster storage, networking etc), rather than trying to expand on a Pi, as you will always be a bit hamstrung. However, me saying that is sure to incur the wrath of certain folks on this forum, so I’ll say no more.

However, me saying that is sure to incur the wrath of certain folks on this forum, so I’ll say no more.

Grrr! Argh! Aaaahhh!

Happy?

There comes a point where one must understand that there are differences between a £35 board, and one with a ‘1’ between the currency symbol and the 35. And one must accept that some things will have to be done a little differently. Yes, you can hook an SSD to a Pi, but no it won’t fly. It will, on the other hand, offer a much more resilient form of flash than an SD card. Because SSDs are designed to be put into computers and used as filesystem drives. SD cards…aren’t.

The SSD I mentioned above, replaced a spinning rust drive, on a BBxM at the time. The speedup was enormous.

I take it you move everything except !Boot onto the SSD?

Everything, including !Boot. The only files on the SDHC are RISCOS/IMG, BOOTCODE/BIN, CONFIG/TXT etc.

Hello sorry to just chime in and ask but to clarify both SD cards and USB drives are not okay for Pi storage? So external HDD or SDD is the best option with USB for backup essential files etc

USB Flash drives are fine for making backups. That is essentially what they were invented for.

But, for frequently used (written to) main drives, SSD or mSATA will give better reliability. That is what they were invented for.

The original post was about Pi Storage, so we are crrently talking about USB 2, which is speed limited and thus will not draw too much current from the Pi. (I still recommend max_usb_current=1 set in config.txt and you will need a 2.5amp power supply). See Rick’s post 13 hours before this.

but to clarify both SD cards and USB drives are not okay for Pi storage?

They are fine. Everyone on here is simply being extra cautious/paranoid!

My Pi1 from 2012 still works off its original SD card, and the ARMini was my primary machine for 5+ years running off its micro-SD card with no errors. The only SD cards I’ve had trouble with have been ones taken in and out a lot, suggesting the contacts are more brittle than the flash.

If you need the best possible performance and reliability, then get an SSD. But unless the data is super critical and you have no backups, then the SD card will serve well enough for playing around on a Pi.