Talk:UBIFS initial experiments: Difference between revisions
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m (New page: Hi, I'd like to comment this: * UBI is taking an extremely long time (~50s) to attach to the MTD device on the XO I am currently using for this testing. UBI attach time does scale li...) |
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I have one more suggestion. |
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Hi, I'd like to comment this: |
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* UBI is taking an extremely long time (~50s) to attach to the MTD device on the XO I am currently using for this testing. UBI attach time does scale linearly w.r.t flash size, however the 50s seems wrong. According to this, we should only take about 2 seconds. At attach time I see a warning "UBI warning: ubi_eba_init_scan: cannot reserve enough PEBs for bad PEB handling, reserved 74, need 79" b/c my system partition has 5 bad PEBs in it and this may be related. TODO: Test on another XO. |
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Currently, you create a JFFS2 partition containing /boot. |
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I'm sure what you do is you erase the partition, then attach it to UBI. In this case UBI first read your partition and makes sure it contains all 0xFF bytes, which means it is empty, then it starts formatting this partition - it erases all eraseblocks again and writes the Erase counter and VID headers. This takes long time. If you attach it for the second time, it'll be fast, because it won't format it. |
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But at the end, when the device has booted, I do not see |
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Please, glance here: http://www.linux-mtd.infradead.org/faq/ubi.html#L_format_mtd |
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any JFFS2 partition mounted. So it seems you use this JFFS2 |
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Please, also glance here: http://www.linux-mtd.infradead.org/faq/ubi.html#L_ubierase |
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partition to boot, then you do not use it. |
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UBIFS image contains a copy of /boot. I thing it is not a |
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Also, make sure you do not have UBI debugging enabled. It slows down things a lot. The same is true for UBIFS. |
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good idea to keep 2 copies. Probably it is better to have |
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/boot on JFFS2, and remove /boot directory from UBIFS at |
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all. |
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OFW will unlikely be able to mount UBIFS because it is |
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HTH, |
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rather complex and would need a lot of work. So probably |
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Artem Bityutskiy. |
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it is OK to have 2 file-systems. |
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Latest revision as of 09:05, 20 October 2008
I have one more suggestion.
Currently, you create a JFFS2 partition containing /boot. But at the end, when the device has booted, I do not see any JFFS2 partition mounted. So it seems you use this JFFS2 partition to boot, then you do not use it.
UBIFS image contains a copy of /boot. I thing it is not a good idea to keep 2 copies. Probably it is better to have /boot on JFFS2, and remove /boot directory from UBIFS at all.
OFW will unlikely be able to mount UBIFS because it is rather complex and would need a lot of work. So probably it is OK to have 2 file-systems.