Re: Compact Flash memory test
Thanks for the info, Alan. Pure luck on my part that I bid on a lot of industrial grade, SLC memory. I could not see that in the photo, I just grabbed the first lot of inexpensive 128MB Compact Flash cards I saw. I am looking forward to testing them and see how many are good before we start to upload the firmware image we have taken off a good unit. We are looking forward to being able to take an engineering unit that we tried many variations on and restore it to baseline, as well as repair any defective memories or corrupted firmware. Mike You made a good choice. As you can see on the label, the cards are Industrial Grade. This means, at least, they have SLC (Single Level Cell) flash in them. SLC is more data reliable and longer lived than MLC (Multi-Level Cell) flash. SLC = store only one bit per flash cell. MLC = store two (or more) bits per flash cell. MLC is higher density for about the same manufacturing cost so sellers like it. It's fine for cameras, etc. but not for computer operation uses, in my opinion. By the label design they are probably from 2002-2003, which is fine unless they've had very heavy use. It would be nice to know their history but, at least they started life as some of the best you could get. Alan --- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
Re: Compact Flash memory test
I just noticed a disconnect in our discussion that may just be a misunderstanding of terms. The cards in the photo you pointed at are PC Card[1] flash memory, not Compact Flash[2]. They each work the same way but are different physical size and connection. I just hope you need the PC Cards you have bought and were just reffering to them as Compact Flash. Some people do use the terms interchangeably but they are physically different. Alan [1] http://en.wikipedia.org/wiki/PC_Card [2] http://en.wikipedia.org/wiki/CompactFlash On Fri, Jan 30, 2009 at 2:58 PM, Mike Bushroe mbush...@gmail.com wrote: Thanks for the info, Alan. Pure luck on my part that I bid on a lot of industrial grade, SLC memory. I could not see that in the photo, I just grabbed the first lot of inexpensive 128MB Compact Flash cards I saw. I am looking forward to testing them and see how many are good before we start to upload the firmware image we have taken off a good unit. We are looking forward to being able to take an engineering unit that we tried many variations on and restore it to baseline, as well as repair any defective memories or corrupted firmware. Mike You made a good choice. As you can see on the label, the cards are Industrial Grade. This means, at least, they have SLC (Single Level Cell) flash in them. SLC is more data reliable and longer lived than MLC (Multi-Level Cell) flash. SLC = store only one bit per flash cell. MLC = store two (or more) bits per flash cell. MLC is higher density for about the same manufacturing cost so sellers like it. It's fine for cameras, etc. but not for computer operation uses, in my opinion. By the label design they are probably from 2002-2003, which is fine unless they've had very heavy use. It would be nice to know their history but, at least they started life as some of the best you could get. Alan --- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss --- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
Re: Compact Flash memory test
From the photo on ebay, they look to be Sandisk. http://tinyurl.com/d9up8f They have not arrived yet, but the machine I will be testing them on I just added an Ubuntu partition to, so I do not have to do any testing in Windoze. Mike -svfw /dev/flashdevice will perform a butteryfly test with 4 passes, which aught to be way more than efficient to notify you of a failing flash volume. This is good advice. I would add that any test that proves a rotating hard drive is good will prove that a flash drive is good. There simply is not a method accessible by a standard customer to determine if the flash in a flash drive is close to bad. Some of the new SATA or PATA hard drive replacements support S.M.A.R.T. that can inform you of potential problems. But even current Compact Flash cards do not support such commands. A 128MB card is most likely a few years old. Manufacturer differences can matter a lot back then. What brand, model, etc. are the cards you bought? Alan --- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
Re: Compact Flash memory test
You made a good choice. As you can see on the label, the cards are Industrial Grade. This means, at least, they have SLC (Single Level Cell) flash in them. SLC is more data reliable and longer lived than MLC (Multi-Level Cell) flash. SLC = store only one bit per flash cell. MLC = store two (or more) bits per flash cell. MLC is higher density for about the same manufacturing cost so sellers like it. It's fine for cameras, etc. but not for computer operation uses, in my opinion. By the label design they are probably from 2002-2003, which is fine unless they've had very heavy use. It would be nice to know their history but, at least they started life as some of the best you could get. Alan On Thu, Jan 29, 2009 at 11:43 AM, Mike Bushroe mbush...@gmail.com wrote: From the photo on ebay, they look to be Sandisk. http://tinyurl.com/d9up8f They have not arrived yet, but the machine I will be testing them on I just added an Ubuntu partition to, so I do not have to do any testing in Windoze. Mike --- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
Compact Flash memory test
We maintaining an embedded Linux device performing the routing functions in an Etherswitch. Up till now, we have sent the boards or entire boxes back to the vendor (G.E.) for any firmware or hardware repair. We are now rethinking this, since the most common hardware failure is the power supply, and they use generic, open frame PC switching power supplies, and defective firmware, which is stored on a 64Mb Compact Flash card. We have now removed one of the flash cards and tarballed the contents and we want to transfer it onto a fresh, never been to GE flash card, plug it in and see if everything works right. So I just bought a lot of 10 128Mb Compact Flash cards that were sold 'As Is. I want to know if anyone knows of a memory tester for Compact Flash cards that are being used as the main file system for a small Linux box. The Flash Card is formatted ext3, but we can probably test them first, then format them for Linux and install the system from the tarball. It would be helpful if the file system test could be run under Ubuntu or Windows XP. Anybody have any suggestions? Does the built in fsck do enough of a check to find bad cells in a Compact Flash card/drive? Mike --- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
Re: Compact Flash memory test
From: Mike Bushroe mbush...@gmail.com I want to know if anyone knows of a memory tester for Compact Flash cards. It would be helpful if the file system test could be run under Ubuntu or Windows XP. When flash goes bad, reads of the same bit may or may not return the same value. So I'd think that doing md5sum /dev/blah 4 times and making sure you got the same result each time would work. Not sure how you'd do this in 'Doze though. Device files exist under 'Doze, they're just a PITA to access and use. Does the built in fsck do enough of a check to find bad cells in a Compact Flash card/drive? Not necessarily. -- Matt G / Dances With Crows The Crow202 Blog: http://crow202.org/wordpress/ There is no Darkness in Eternity/But only Light too dim for us to see --- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
Re: Compact Flash memory test
On Tuesday 27 January 2009 15:10:16 Matt Graham wrote: From: Mike Bushroe mbush...@gmail.com I want to know if anyone knows of a memory tester for Compact Flash cards. It would be helpful if the file system test could be run under Ubuntu or Windows XP. When flash goes bad, reads of the same bit may or may not return the same value. So I'd think that doing md5sum /dev/blah 4 times and making sure you got the same result each time would work. Not sure how you'd do this in 'Doze though. Device files exist under 'Doze, they're just a PITA to access and use. Does the built in fsck do enough of a check to find bad cells in a Compact Flash card/drive? Not necessarily. Running badblocks -svfw /dev/flashdevice will perform a butteryfly test with 4 passes, which aught to be way more than efficient to notify you of a failing flash volume. --- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
Re: Compact Flash memory test
On Tue, Jan 27, 2009 at 6:01 PM, Nathan England Running badblocks -svfw /dev/flashdevice will perform a butteryfly test with 4 passes, which aught to be way more than efficient to notify you of a failing flash volume. This is good advice. I would add that any test that proves a rotating hard drive is good will prove that a flash drive is good. There simply is not a method accessible by a standard customer to determine if the flash in a flash drive is close to bad. Some of the new SATA or PATA hard drive replacements support S.M.A.R.T. that can inform you of potential problems. But even current Compact Flash cards do not support such commands. A 128MB card is most likely a few years old. Manufacturer differences can matter a lot back then. What brand, model, etc. are the cards you bought? Alan --- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
