SSD read-only state.
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Ron Anders wrote:
Then I thought, you don't suppose some blocks in the project folder have got read only do ya?
That's not how SSDs work. In order to prevent a single block being "pounded upon" too much (think of the FAT table), they use wear leveling. This means that a particular LBA doesn't map to a particular physical block. Some physical blocks on the SSD are reserved as "spares", to handle the case of blocks that have gone read-only. This is handled transparently by the SSD's firmware. The SSD will typically go read-only only when all the spare blocks have been used. Your description shows that this was not the case. I would look elsewhere for the cause of the error in VS.
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows. -- 6079 Smith W.
Thanx for this clarity on SSD. My SSD quotes "Global wear-leveling evens program/erase counts across data blocks to extend lifespan" which is what I think you were referring to. Never saw this spec until you brought it up.
"A little time, a little trouble, your better day" Badfinger
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Ron Anders wrote:
Then I thought, you don't suppose some blocks in the project folder have got read only do ya?
That's not how SSDs work. In order to prevent a single block being "pounded upon" too much (think of the FAT table), they use wear leveling. This means that a particular LBA doesn't map to a particular physical block. Some physical blocks on the SSD are reserved as "spares", to handle the case of blocks that have gone read-only. This is handled transparently by the SSD's firmware. The SSD will typically go read-only only when all the spare blocks have been used. Your description shows that this was not the case. I would look elsewhere for the cause of the error in VS.
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows. -- 6079 Smith W.
I had one of my early USB memory sticks (not an SSD disk intended to replace a magnetic disk) more or less permanently sitting in the USB socket. This was in the days of Win XP, which wasn't very much aware of the special nature of Flash. I noticed that the LED on the stick lit up regularly (and quite frequently), but thought nothing of it until the stick started failing. I did a full formatting, ending up with a lot of bad pages, and used it for some more time, but soon more pages went bad. That is when I first heard about wear leveling, and of the new Win 7 being "Flash aware", doing more extensive buffering to reduce the number of writes of OS data to the Flash device. So: Once upon a time, Flash wear-out was a problem - probably more so on USB sticks. It might have been a problem even on SATA SSDs in their very earliest days, before wear leveling became standard. (That is a number of years ago!) Note: Wear leveling is only applied to writing of pages that are being written/modified. Unmodified pages are not moved around to reduce wear. So it is no good idea to fill up your SSD to 99.9% of read-only files, and keep up heavy write/modify traffic on the last 0.1%. Keeping a fair share of the disc unused will spread the wear over more physical blocks, with less wear on a each of them. (This is of course of minimal concern if you do not make lots of writes to the remaining 0.1%!)
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Agreed. I've had only 1 "set" of SSDs from Crucial screw me over. They had a firmware bug, and after X hours of being ON, they would start powering off! BTW, we don't use Crucial SSDs anymore. We had 3 computers (laptops) with this issue. I Found it first. Then another developer. The third developer was able to clone his drive and spare himself a lot of heart burn. The Second Developer was stuck in a conundrum. The time the SSD would stay alive << the time required to clone! Thankfully we have spare drives, clones, and backups. But it was REALLY hard to figure out at first. The machine would boot, then just crash with the drive going offline. In general, I've tested an SSD on a TiVo for years. Wear leveling works. And if your SSD is so old, it doesn't have wear leveling... Then you A) Should have FAILED already! B) Should have cloned it and upgraded about 2-3 years ago!
> I've had only 1 "set" of SSDs from Crucial screw me over. I can one-up that. I've only lost 1 ssd (mushkin), and I maintain it was not the ssd's fault. Stay with me. Back around 2017, after about 3 years of not changing any significant hardware, one day I get an IO error when trying to boot. Booted a live dvd and confirmed the disk was visible but simply refused to mount. So I shut it down and switch off the psu (normally I leave them plugged in but hardware switch off at the psu so it can stay grounded). I go to remove the ssd and I notice the hdd next to it was vibrating like it's still on. So I figure the rocker is dead/shorted and unplug the pc and take my chances with the static. It's still vibrating. Thinking I'm hearing things, I take a multimeter to the nearest open molex and find the 5v and 12v pins both read as 5v. So I start unplugging everything. Turns out it was my powered usb hub. Whenever the machine was off, the little 5V 2A wall wart was holding the whole system 12v line at 5v, apparently too low for any fans or cpu or any indicators of something being powered other than the half-speed hdd spinning. So the ssd was routinely subjected to a 12v and 5v rail pair that had no difference in voltage. Now I'm suprised the ssd was the only thing to break after 3 years. I still use the hub by the way, just with the usb cable between it and the pc modified to no longer connect the red wire.
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> I've had only 1 "set" of SSDs from Crucial screw me over. I can one-up that. I've only lost 1 ssd (mushkin), and I maintain it was not the ssd's fault. Stay with me. Back around 2017, after about 3 years of not changing any significant hardware, one day I get an IO error when trying to boot. Booted a live dvd and confirmed the disk was visible but simply refused to mount. So I shut it down and switch off the psu (normally I leave them plugged in but hardware switch off at the psu so it can stay grounded). I go to remove the ssd and I notice the hdd next to it was vibrating like it's still on. So I figure the rocker is dead/shorted and unplug the pc and take my chances with the static. It's still vibrating. Thinking I'm hearing things, I take a multimeter to the nearest open molex and find the 5v and 12v pins both read as 5v. So I start unplugging everything. Turns out it was my powered usb hub. Whenever the machine was off, the little 5V 2A wall wart was holding the whole system 12v line at 5v, apparently too low for any fans or cpu or any indicators of something being powered other than the half-speed hdd spinning. So the ssd was routinely subjected to a 12v and 5v rail pair that had no difference in voltage. Now I'm suprised the ssd was the only thing to break after 3 years. I still use the hub by the way, just with the usb cable between it and the pc modified to no longer connect the red wire.
Wow... That wins! Thanks for sharing... FWIW, I am always concerned with device power issues. And I cannot stand the new "feature" whereby my laptop powers the USB ports when it is off! It just doesn't seem "right"...
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Wow... That wins! Thanks for sharing... FWIW, I am always concerned with device power issues. And I cannot stand the new "feature" whereby my laptop powers the USB ports when it is off! It just doesn't seem "right"...
100% with you there. My laptop has the ability to switch that off in bios. Too bad bios resets itself every time it is turned off and not connected to its power cable (replacing the cr2032 did not fix that). As for usb charging my phone, well that's half the reason I had a powered usb hub in the first place :). Though now I mostly use the usb port on my ups.
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Wow... That wins! Thanks for sharing... FWIW, I am always concerned with device power issues. And I cannot stand the new "feature" whereby my laptop powers the USB ports when it is off! It just doesn't seem "right"...
It doesn't seem right because it's wrong. First rule of UI- never lie to the user. Ever.
Charlie Gilley “They who can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety.” BF, 1759 Has never been more appropriate.