From: Blaisorblade <bla...@ya...> - 2005-09-23 20:12:47
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On Wednesday 21 September 2005 17:48, Alasdair G Kergon wrote: > On Tue, Sep 20, 2005 at 04:34:33PM -0700, Andrew Morton wrote: > > ack? > > Applied some quick corrections to this. I'm now looking at this, but you've done an error. You say that You must create the snapshot-origin device before you can create snapshots. This is totally wrong. The whole point of my document is to show that you can create snapshots *WITHOUT* having a snapshot-origin device (yes, I did it). And while the LVM setup (with snapshot-origin) is often used and well known, the possibility to do without the snapshot-origin, and more important to write on the snapshots, is something which is not widely known at all. In fact, UML community has been using an in-house version of the same feature, which cannot be mounted on the host due to missing code. > See also http://people.redhat.com/agk/talks/FOSDEM_2005/ > (slides 15-27) Not yet had time to look at those, sorry. > You might like to convert some of those diagrams to ASCII > and include them? If you feel like doing this, ok, but I'm not normally a documentor. > Alasdair -- Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!". Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894) http://www.user-mode-linux.org/~blaisorblade ___________________________________ Yahoo! Mail: gratis 1GB per i messaggi e allegati da 10MB http://mail.yahoo.it |
From: Alasdair G K. <ag...@re...> - 2005-09-23 21:20:15
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On Fri, Sep 23, 2005 at 10:11:31PM +0200, Blaisorblade wrote: > you can create snapshots *WITHOUT* having a snapshot-origin device Checking the code, yes you're correct. When that LVM2 code was developed you'd get an oops but it's been fixed. Alasdair -- ag...@re... |
From: Blaisorblade <bla...@ya...> - 2005-09-27 17:28:37
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On Friday 23 September 2005 23:19, Alasdair G Kergon wrote: > On Fri, Sep 23, 2005 at 10:11:31PM +0200, Blaisorblade wrote: > > you can create snapshots *WITHOUT* having a snapshot-origin device > Checking the code, yes you're correct. > When that LVM2 code was developed you'd get an oops but it's been fixed. You also "fixed" my assertion that snapshot-origin "base device" (parameter n.1) must be a DM device. Should I readd it too? IIRC I checked the code and it looks up the first param as a DM device, even because the list of snapshot is maintained for DM devices, not for general block devices. Right? > Alasdair -- Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!". Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894) http://www.user-mode-linux.org/~blaisorblade ___________________________________ Yahoo! Messenger: chiamate gratuite in tutto il mondo http://it.messenger.yahoo.com |
From: Alasdair G K. <ag...@re...> - 2005-09-27 18:34:45
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On Mon, Sep 26, 2005 at 05:03:01PM +0200, Blaisorblade wrote: > You also "fixed" my assertion that snapshot-origin "base device" (parameter > n.1) must be a DM device. Should I readd it too? That parameter does not need to be a DM device if you are able to use the start of an existing block device (so you don't require any mappings). > IIRC I checked the code and it looks up the first param as a DM device, It should only use the device number for reference, not any dm structure. Try it. Alasdair -- ag...@re... |