[Gluster-devel] AFR / Self Heal

Gareth Bult gareth at encryptec.net
Sun Jan 13 15:05:50 UTC 2008


Hi, 

At the moment, to kick in a self-heal on an AFR volume, it seems you need to close and re-open a given file. 

Also, while a self heal is in progress, the file will not open fully and cannot be used until the heal completes. 

Looking at the roadmap for 1.4 the implication is that these features may be added .. 

Can anyone can confirm this and possibly indicate how long it's likely to take for this to become available ? 

just fyi; 

Using XEN images at the moment on gluster FS it goes like this; 

Migration 
======= 

xm migrate -l domain nodeb -- takes 3-4 seconds with less than 1 second downtime 

Gluster restarts 
============ 

killall glusterfsd 
glusterfsd 
(all images are now running off other nodes) 

For each XEN instance; 

xm save domain /tmp/domain (4 seconds) 
head -c1 /gluster/images/domain.disk > /dev/null (~20 seconds) 
xm restore /tmp/domain (4 seconds) 


1) being able to start a self-heal and simply blocking an open file would save 30% of the time required 
2) not having to copy a 2-3Gb image but instead use failed transactions would probably save 95%+ 

Gareth. 



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