On Tue, Feb 9, 2021 at 3:29 PM pmkellly@xxxxxxxxxxxx <pmkellly@xxxxxxxxxxxx> wrote: > > > > On 2/9/21 13:19, Chris Murphy wrote: > > On Tue, Feb 9, 2021 at 10:23 AM pmkellly@xxxxxxxxxxxx > > <pmkellly@xxxxxxxxxxxx> wrote: > >> > >> > >> I've seen several ISOs lately that after they were written to a thumb > >> drive using media writer they wouldn't boot. I won't be recounting the > >> details I sent in prior motes to @test, but here is a little more > >> information. > >> > >> The last one I tried was Workstation Live 0207.n.0. It failed to boot > >> initially, but I rewrote the same downloaded image to the same thumb > >> drive with Media Writer again. After that it would boot. This might > >> raise the possibility that Media Writer is involved with the boot > >> problems. I guess I'll just keep track of this from now on. > >> > >> I have been using the same thumb drive plugged into the same USB port > >> all along. Today just for grins I ran badblocks on the thumb drive and > >> no bad blocks were found. "badblocks -w -s -o Thumberror.log /dev/sdb)" > > > > I would use f3. The gist is format the USB stick (file system doesn't > > matter) and mount it. Then > > > > sudo f3write /mnt > > sudo f3read /mnt > > > > Actually f3 is part of the Fedora repos now. I decided to use badblocks > because I understand it's tests. It's the same basic tests I run on a > new board prototype when there is ram or flash on the board. Besides > testing the memory, it allows me to check the address and data buses > too. Though this does not apply when testing a USB Flash decvice. > > As I understand f3 it just writes files to the flash and reads them back > checking for errors. I'll go ahead and try f3 on the same thumb drive. It can distinguish between different kinds of problems. > Well I only use Flash from reputable manufacturers and though I never > trust any single flash drive with anything important they have provided > good results for me. Also, it's not clear that the flash drive is the > problem in this case. The fake flash folks have gotten very good at faking seemingly legit hardware down to the packaging. It's not so much reputable brand as it is reputable reseller. > > Way beyond flash drive fraud. Flash drives, especially the NOR types > which seem to be the most common have a few error modes. Though some > manufacturers advertise they have new designs good for millions of write > cycles. Most of those available now only do about 100K cycles. Following > my de-rating rules I never implement flash in any case where more than > 50K cycles will be required. An install ISO puts a lot of data on the > thumb drive. Then there are the wear leveling strategies to take into > account to work out how all the spare blocks get used etc. Estimating > the number of Live install cycles a thumb drive should be relied on will > be hard and mostly guess work. Even so I would think they should be good > for a thousand installs. This thumb drive only has about a hundred on it. Well it's a bit needle in a haystack trying to track down transient boot problems. > >> Side note: With 0207 I once again encountered the white screen sad face. > >> when I rebooted after the initial install to do the complete the install > >> tasks. The complete the install windows popped up on top of the sad face > >> and I was able to coomplete the install. I did a restart after > >> completing the install. The restart ran normally and I have seen no > >> problems. Though I havent tested 0207 extensively. I'll get started > >> again when Branched F34 is available. > > > > This could also be transient corruptions on read. USB sticks > > notoriously do not report discrete read errors, they just return bad > > data. > > > > Well I don't have my thumb drive plugged into my test machine when power > up or down. Restarts do not change the power supply state. At least > that's the case on my Lenovo machines. My work area is fully static > protected. I really doubt the +5VDC supply in my test machine is > producing any transients. There would be other highly observable > effects. Though with some trouble I could get a scope and monitor it if > someone believes that might be the trouble. Oh I thought you were booting from that same stick, but it had been imaged with a different ISO. If the media is failing, the manifestation of the failure can be different between uses. -- Chris Murphy _______________________________________________ test mailing list -- test@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to test-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/test@xxxxxxxxxxxxxxxxxxxxxxx
