Opened 15 years ago

Last modified 15 years ago

#9682 closed Developer Task

Myth Backend handles loss of NFS mount poorly — at Version 1

Reported by: danielk Owned by: danielk
Priority: minor Milestone: unknown
Component: MythTV - General Version: Master Head
Severity: medium Keywords:
Cc: Ticket locked: no

Description (last modified by beirdo)

When an NFS server goes down in the middle of a recording any of the backend's ThreadedFileWriters writing to that disk become permanently wedged and CPU usage shoots up to near 100%.

Using aio_write() instead of write() should allow us to better handle this condition. We should at minimum not use 100% CPU, and ideally continue recording to other disks including with the currently blocked recorder.

Change History (1)

comment:1 by beirdo, 15 years ago

Description: modified (diff)
Summary: Myth Backend handles loss of disk poorly → Myth Backend handles loss of NFS mount poorly

First thing to do... if you are worried about NFS mounts disappearing, mount them with options "soft,intr,retrans=6". The default is "hard,nointr,retrans=3". There is some risk of lost data due to doing this, but the NFS connection will no longer indefinitely hang.

Additional to that, the aio_write() may be a good plan (is this portable, and will it have the desired affect on non NFS writes?)

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