XPost: alt.os.linux   
   From: nospam@needed.invalid   
      
   On 7/13/2022 10:16 PM, Paulo da Silva wrote:   
   > Hi!   
   >   
   > I have a USB external backup volume with btrfs.   
   > The backup script is a simple cp -al   followed by a rsync to   
   update .   
   >   
   > The cp -al took 10-20 mins. in kernel 5.13 and before that.   
   > Now, with 5.15, without any changes, it is taking a few hours!!   
   >   
   > NOTES:   
   > I have noticed that before, during the cp -al there were outputs to the   
   memory cache during which we could "visit" the drive followed by periods of   
   flushing where a simple attempt to change to another dir took a while   
   (sometimes ~1 min).   
   >   
   > Now, I can always navigate inside the drive without any delay when cp -al is   
   in course! It seems like there is no memory cache although the memory cache   
   still grows and shrinks.   
   >   
   > BTW, my mount command is   
   > mount /dev/mapper/TEMP /mnt1 -onoatime,compress-force=zstd   
   >   
   > There is an encryption layer below the fs.   
   >   
   > Thanks for any comments.   
   > Paulo   
   >   
      
   What happens if you turn off the encryption ?   
      
   I would want to study the component parts of   
   the stack, to see if they behave decently by   
   themselves.   
      
   Even if you temporarily had two disk drives,   
   one set up with the full stack of stuff,   
   the second drive with the encryption layer   
   nullified, that may allow you to bench the   
   two and see how much worse one is than the other.   
      
       Paul   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)