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On 03/31/10 03:44, David Relson wrote: |
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> The many suggestions have been very helpful. This afternoon, |
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> 'sync' was added to fstab. No problems have been seen since. |
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> While not conclusive, the indication is good and we're helpful. |
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> |
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> The device in question is a medical device that continuously takes |
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> readings, graphs them, and every 30 seconds appends a 34 byte data |
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> record to each of two files. It's not exactly disk intensive :-> |
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Even with data amount is low, you're still looking at something like ~3 x16KB |
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(eraseblock, which could be significantly larger) number of erases cause some |
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data should be updated in place. I would be writing into one file with writes |
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aligned to flash pagesize. |
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If someone hits the power button while flash is working, sync won't help on |
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ext2. Backup power is present, why not to wire power button so that shutdown can |
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be signaled and emergency sync() is performed on filesystem... |
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While ext3 is mature, ext4 has journal checksums. |
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> FWIW, often the files hit by the "Stale NFS file handle" problem are |
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> symlinks in /usr/lib. Since _nobody_ writes that directory it's odd |
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> that the problem often shows up there. That's not the only place, but |
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> seems to be the most common one. |
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Weird errors may indicate toolchain problems with in errno.h not matching kernel |
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version. |
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> The power cord isn't a problem -- there's an onboard battery. However |
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> the power button can be pressed at any time. 'Tis something that we'll |
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> live with. Adding fsync() calls, in addition to 'sync' mounting, should |
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> help. |
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I believe it is same and you need only one method. |
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