cloudstack-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ASF subversion and git services (JIRA)" <>
Subject [jira] [Commented] (CLOUDSTACK-7345) Copy snapshot command can cause NFS timeouts, breaking the snapshot process.
Date Thu, 14 Aug 2014 08:14:11 GMT


ASF subversion and git services commented on CLOUDSTACK-7345:

Commit 7c92bac4a35dacba03883532ab6ebe638638b26c in cloudstack's branch refs/heads/master from
[;h=7c92bac ]

CLOUDSTACK-7345 changed dd blocksize to 128k when using NFS.

Signed-off-by: Daan Hoogland <>
(cherry picked from commit 8b7130fa65a3ce010a54015b3350b94b56414462)

> Copy snapshot command can cause NFS timeouts, breaking the snapshot process.
> ----------------------------------------------------------------------------
>                 Key: CLOUDSTACK-7345
>                 URL:
>             Project: CloudStack
>          Issue Type: Bug
>      Security Level: Public(Anyone can view this level - this is the default.) 
>          Components: Snapshot, XenServer
>    Affects Versions: 4.0.0, 4.0.1, 4.0.2, 4.1.0, 4.2.0
>            Reporter: Brenn Oosterbaan
> When multiple snapshots are being transferred from NFS primary to secondary storage at
the same time, NFS timeouts on the primary storage can occur.
> This then breaks most of the snapshot processes, resulting in corrupted (half completed)
> The DD command used uses 'bs=4M', which is then chopped into 64 64k reads since the primary
storage is mounted with a blocksize of 64k, and written to the secondary storage as 32 128k
blocks (since secondary is mounted with blocksize 128k).
> We created a patch changing the DD command to use 'bs=128k' (unless iSCSI is used in
which case it stays at bs=4M).
> Snapshot processes no longer break, and no negative performance impact.

This message was sent by Atlassian JIRA

View raw message