I think this is really an attempt at user feedback, rather than user discussion. But there's no such thing as a user-feedback mail list. Nevertheless, others may find this pertinent: why doesn't mke2fs handle USB's competently? And if it does, why doesn't it reassure me so? And how can I handle a linux-formatted USB flash drive in the absence of my system giving me any guidance? I cannot accept the usual advice you see in the forums: simply format it FAT16 or whatever. I need it to use a linux file system. But linux may have problems, apparently, with the device: http://lwn.net/Articles/428584/ Plenty of people say in the forums that ext3 and ext4 will wear your USB out quickly, effectively thrashing it with their journaling. But the above-linked article suggests it may depend on the device. Some people say ext4 is simply okay, some that it is actually advisable to use it. I'm none the wiser. If it is true that ext4 will thrash your USB then it could important if it is also true that, for example, the life-expectancy of a USB can really as low as 10,000 writes: http://linux.koolsolutions.com/2009/01/29/installing-linux-on-usb-part-3-which-linux-filesystem-for-usb-devices/. I spoke to Integral Memory, the manufacturer of my USB drive. Their technical support line said their device had a life expectancy of 1000 writes, and came with a two-year warranty. He didn't know what he was talking about. None of Integral's publically available spec-sheets tell you anything useful. They give an approximate write-speed and that's about it. Nothing about block size, whether optimized for linear write or not, what method of wear distribution they use - all the things you are led to believe may be important in deciding whether you should format your USB ext4 or not. Of course, I shouldn't have to know about any of these things as a user anyway. But I'm left with no choice but to lower myself into this arcane realm and get in a tangle. One of the things I'm led to believe I must consider when formatting a USB drive is its physical block size. This appears to be something of a mystery, but someone reckons he has worked out a simple method of discerning it: http://kim.oyhus.no/FlashBlockSize.html. Using that method, and assuming Kim G. S. Øyhus is correct, my drive seems to have 4k block size. Now perhaps if I format my drive with a filesystem that uses a 4k block size I might stop it being mashed by ext4. Perhaps. It does seem strange to me though that mke2fs doesn't already do this for me: discerns what's going on underneath the casing of my USB, adjust its formatting parameters accordingly - and tell me what its doing so I can be reassured. Or that the help pages at least tell me definitively whether and in what circumstances it can be used with USB so I don't have to waste so much time trying to unravel the mystery by going like a pinball from one contradictory, incomplete or well-meaning nincompoop forum message to another; and so I don't mash my USB, and lose my data, because I should have listened to the pessimists and not put an ext4 filesystem on my USB. I actually don't want to believe them. But they shout loudest. mb. _______________________________________________ Ext3-users mailing list Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users
