-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/24692/
-----------------------------------------------------------

Review request for cloudstack, daan Hoogland, Joris van Lieshout, and Sanjay 
Tripathi.


Bugs: CLOUDSTACK-7345
    https://issues.apache.org/jira/browse/CLOUDSTACK-7345


Repository: cloudstack-git


Description
-------

CLOUDSTACK-7345 patch to change dd command from 4M to 128k when using NFS


Diffs
-----

  scripts/vm/hypervisor/xenserver/vmopsSnapshot 85444dc 

Diff: https://reviews.apache.org/r/24692/diff/


Testing
-------

Starting multiple dd commands with bs=4M on a single hypervisor causes nfs 
server timed out messages in /var/log/kern.log and causes the dd process to 
crash.
With bs=4M NFS debugging shows 64 seperate 64k reads are done, after which the 
inode is updated 64 times (access time) and 32 128k writes are done to 
secondary storage.
NFS debugging showed the 'nfs server timed out' messages usually occured during 
the 64 inode updates (of the same file) from the read process.

Running multiple dd commands with bs=128k on a single hypervisor does not cause 
nfs server timed out messages in /var/log/kern.log.
With bs=128k NFS debugging shows 2 seperate 64k reads are done (and indoe 
updates) and 1 128k write is done.

We are running this change in production. The nfs server timed out messages are 
gone and not a single snapshot process has broken (previosuly this happened 
every night).


Thanks,

Brenn Oosterbaan

Reply via email to