Grrrr!

Set up a new (recycled) SD card on my Pi over the weekend, using only half of the 4GB available. Took forever, copying from USB SD to native SD is like the slowest thing on earth.
And last night? Some time during the night the card failed. Pi wouldn’t even boot. So I’m back to the original.
Thankfully I took an image of the copied card after setting up everything, and as it has only been a couple of days I don’t think I’ve lost much – a little bit of work finishing BreakAid that I can do again, and… that’s about it.

So here’s a little reminder – fire up Win32DiskImager (or equivalent) and take a snapshot of your SD card. You’ll never know when you might need it.

I recall being told that until you have three copies of your data you don’t have it!
Two copies aren’t enough as I’ve heard more than once of people wanting to revert to a previous version and in trying to do so got confused and overwrote the earlier version with the later unwanted version.

In the end, nothing lost (except from my bank account ;-) ).

I could mount the FAT partition on the 4GB card on the PC using an SD reader. So I tried it in the Pi, remembered to RMKill Fat32FS so I could right-click to access the FileCore partition. It worked. So I copied across the source codes and that was that.

I’m using the original 2GB card I’ve had since forever. So given the difficulty of getting 2GB cards, the fact that they’re all like Class Zero (treacle speed), and that recycling an older card obviously brings “issues”, I’ve gone ahead and put in an order for <a href=" http://piccolosystems.com/disctools/systemdisc">SystemDisc so I can just set up a fresh 8GB card and be done with it. Will also have enough disc space for my playlist as well. ;-)
Given the £ sucks right now, it only cost ~€17.60. I had put off ordering it earlier as it would have cost more like €22+.

BTW – can anybody explain why there are no longer direct downloads? I get that it is because of the mind-numbingly stupid EU VAT law that has no concept of a lower threshold; however isn’t a sale a sale regardless of whether it is downloaded off the website or sent by email?
Don’t get me wrong, I’m not being impatient (I don’t even have an SD card to use it with!), I’m just wondering why the distinction.

Okay, off to sit in the garden now the heat is easing off to fire up my e-reader and continue reading a fan translation of Shinsekai Yori (From The New World; a rather nice speculative sci-fi horor drama story – wikilink). ☺

PS: Chris – that’s what CVS/SVN are for. For simpletons like me, each major build is archived in a zip file carrying the version number, so it is possible to revert or compare old/new. It’d be easier with a proper version control system, but that’s a PITA to set up.

Okay, off to sit in the garden now the heat is easing off to fire up my e-reader and continue reading a fan translation of Shinsekai Yori (From The New World; a rather nice speculative sci-fi horor drama story – wikilink).

I have seen the anime version a few years ago, it was my favourite anime of the year. Ah, that revelation about the rat like race in the last episode, it makes so much sense but I had not seen it coming at all!

@ Chris: I subscribe to the 3-copy rule as well. I’m also a big fan of Piccolo’s !CloneDisc. As to SD cards generally, I’ve found them to be very reliable: I use the 4GB size exclusively, and every week make a diskimage using CloneDisc as a backup, which gets saved to the PC and Linksys NAS. Imaging or re-imaging the SD card takes less than 20mins to/from the PC. All my work files are on a USB memory stick, which is faster anyway.

André: Hey! Spoilers! :-P

I downloaded the series “back in the day”, will make time to watch it after reading the book. I began when it was originally on, but didn’t get very far (I think I was working night shift then, so not a surprise I remember nothing).
I do have a suspicion about the queerats, I wonder if it’ll be correct…

George:

While SD/Flash is fairly reliable, I’ve had failures too – the problem is that failures tend to be sudden and usually catastrophic. Unless a harddisc is physically damaged, a failed sector is a failed sector, but it seems with flash it’s more an “all or nothing” situation. Plus, since it is the act of repeated writing that kills flash, usually it’s the root directory that gets trashed first. I do wonder how many times RISC OS clobbers certain parts of the disc (free space map, for instance) for every write. For instance, if one creates a file of zero bytes and adds one byte a thousand times, it should be that the free space map is only updated the once (as 0-1000 bytes should fit into the same allocation and not need anything else changed). Is this so? Or it is 1000 writes? These sorts of things were inconsequential with spinning rust, but could have consequences with flash based media (and don’t forget, the erase-rewrite cell is usually pretty damn large – I rewrite my (small) webserver homepage every five minutes with updated weather information; it may well be that 64K-256K of data is erased and rewritten every time.

I do the imaging directly on a PC with Win32DiskImager. Much quicker to transfer the data directly from SD to USB harddisc.

It’s quicker to use a USB than SD card? Even something like a Class 10 card? I’ve already complained about how SLOW it was to copy files to an older SD card (Class 4), plus RISC OS builds aren’t terribly fast, so speed tips always welcome!

Okay. Got an 8GB SanDisk SD card, after checking it was reported at working on… that RPi site with all the info (can’t remember the name right now).¹
Formatted it with HFORM.
Used SystemDisc to botch in a FAT “partition” so it’ll boot.

I created a dual-boot card by putting in place the Beagle xM boot stuff and the latest ROM, followed by the Pi boot stuff. I did get a picture out of the Beagle (something horrid like 640×480) however when I tried *ReadEDID, the picture vanished and nothing was going to bring it back this time. I’m thinking the OMAP just can’t hack a 1280×1024 display…

As this card was a class 10 instead of a class 2… I set it to copy the files across from the older card and went to cycle the rubbish bags up for collection (about half a mile up the driveway (!)). It was done by the time I came back. Yikes, that was kinda nippy compared to the previous card(s).

So now running with the new card, and with ~5GiB free too. Whoo. ;-)

¹ And kudos to mom for finding something that looked enough like a part number to match with the compatibility chart. The 8GiB microSD works. The 16GiB one doesn’t. Strange, but there you go…

Unless a harddisc is physically damaged, a failed sector is a failed sector, but it seems with flash it’s more an “all or nothing” situation. Plus, since it is the act of repeated writing that kills flash, usually it’s the root directory that gets trashed first.

All “proper” flash media features wear levelling. And they have quite a few spare blocks available that they shuffle around.

With flash memory, I never had the problem of “bad blocks” being killed by being written too often. It was always a complete failure usually indicating broken controller electrics.

Biggest quality problem is fake products – there is a large amount of low quality no-name flash memory around that reaches us being “re-labeled” as if having been produced by a major brand.

Ah, that revelation about the rat like race in the last episode, it makes so much sense but I had not seen it coming at all!

I had a hunch at about the same time Saki should have – talking to the false minoshiro (library)¹ at summer camp. Specifically if they were so gung ho messing with the genetics of Cantus users (death feedback), what else would they mess with?

¹ Makes sense in context. If you like sci-fi, it’s well worth a read.

There is a reason there is a size and cost difference between a MicroSD card an an SSD. Running anything off an SD card makes me squirm a little because they are designed for archives, like photos, music, documents etc. Not to be pounded at relentlessly by the host device.

Any solid state device can’t handle repeated writes too well. They are getting better but it’s still a high wear operation.
Mechanical hard drives are better suited to repeated writes at the cost of speed. They can have an extremely long life if they are looked after. I decomissioned one of my hard drives after over 7 years of uptime. That was the figure I pulled from it, and it seems about right.

On the subject of knockoff SD cards, USB drives etc. Beware! Even big retailers aren’t immune to getting fake products. Also big retailers aren’t beyond selling generic junk for premium prices either. Caveat emptor.