Detaching a cachine device
Hi,
I'm probably overlooking the obvious, but (as part of a test) I want to replace my caching device with a bigger one. So I think the first step should to detach the current caching device. I can find instructions about detaching a backing device, but that's not wat I want (the backing device holds the (slow) data, the important data). I can't figure out though how to detach a caching the device.
Any suggestions would be welcome,
Thanks,
Rolf
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Quoted 6 lines
I'm probably overlooking the obvious, but (as part of a test) I want to replace my caching device with a bigger one. So I think the first step should to detach the current caching device. I can find instructions about detaching a backing device, but that's not wat I want (the backing device holds the (slow) data, the important data). I can't figure out though how to detach a caching the device.
Cache sets have an 'unregister' action: /sys/fs/bcache/<uuid>/unregister The reference docs are in bcache.txt.
http://atlas.evilpiepirate.org/git/linux-bcache.git/tree/Documentation/bcache.txt?h=bcache-dev#n367
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Re: Detaching a caching device
Yep, works indeed.
Dispite the alarming description :-)
Suggestion for alternative text: "Detaches all caching devices and closes them; if any data is present in the caching devices it will ..."
Quoted 12 lines · Rolf Fokkens
Quoted 1 line · Gabriel de Perthuis
Cache sets have an 'unregister' action: /sys/fs/bcache/<uuid>/unregister The reference docs are in bcache.txt. http://atlas.evilpiepirate.org/git/linux-bcache.git/tree/Documentation/bcache.txt?h=bcache-dev#n367
I noteced that one, but it looks kind of scary to me:
|"Detaches all backing devices and closes the cache devices; if dirty data is present it will disable writeback caching and wait for it to be flushed.| Sounds like one of these:
- the/dev/cache*devices are gone; if so: that's definitely not what
I want.
- or at least the the baching devices are detached; that also sounds
bad. I don't want to detacht the backing devices at all, I want to detacht the caching device.The text is somewhat confusing to me. I'll give it a try, it's only a VM.
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Re: bcache-status shows now output when caching device detached
When no caching devices are connected, bcache-status shows nothing. Although actually no caching happens, it's confusing.
Quoted 21 lines · Rolf Fokkens
Yep, works indeed.
Dispite the alarming description :-)
Suggestion for alternative text: "Detaches all caching devices and closes them; if any data is present in the caching devices it will ..."
Quoted 13 lines · Rolf Fokkens
Quoted 1 line · Gabriel de Perthuis
Cache sets have an 'unregister' action: /sys/fs/bcache/<uuid>/unregister The reference docs are in bcache.txt. http://atlas.evilpiepirate.org/git/linux-bcache.git/tree/Documentation/bcache.txt?h=bcache-dev#n367
I noteced that one, but it looks kind of scary to me:
|"Detaches all backing devices and closes the cache devices; if dirty data is present it will disable writeback caching and wait for it to be flushed.| Sounds like one of these:
- the/dev/cache*devices are gone; if so: that's definitely not what
I want.
- or at least the the baching devices are detached; that also sounds
bad. I don't want to detacht the backing devices at all, I want to detacht the caching device.The text is somewhat confusing to me. I'll give it a try, it's only a VM.
A message that is not in the archive (sent off-list or not yet received): [email protected]
Re: bcache-status shows now output when caching device detached
Quoted 2 lines · Rolf Fokkens
When no caching devices are connected, bcache-status shows nothing. Although actually no caching happens, it's confusing.
Aha, I didn't quite understand what you were getting at until I broke one of my cachesets.
Yes, it would be useful to have it report orphaned cache / backing devices, since right now it only prints full sets in /sys/fs/bcache/$uuid/.
--D
Quoted 32 lines · Rolf Fokkens
Quoted 29 lines
Yep, works indeed.
Dispite the alarming description :-)
Suggestion for alternative text: "Detaches all caching devices and closes them; if any data is present in the caching devices it will ..."
Quoted 19 lines · Rolf Fokkens
Quoted 3 lines · Gabriel de Perthuis
Cache sets have an 'unregister' action:
/sys/fs/bcache/<uuid>/unregister The reference docs are in
bcache.txt. http://atlas.evilpiepirate.org/git/linux-bcache.git/tree/Documentation/bcache.txt?h=bcache-dev#n367I noteced that one, but it looks kind of scary to me:
|"Detaches all backing devices and closes the cache devices; if dirty data is present it will disable writeback caching and wait for it to be flushed.|
Sounds like one of these:
- the/dev/cache*devices are gone; if so: that's definitely not what I want.
- or at least the the baching devices are detached; that also sounds bad. I don't want to detacht the backing devices at all, I want to detacht the caching device.The text is somewhat confusing to me. I'll give it a try, it's only a VM.