Kristan McDonald
Dabbler
- Joined
- Jun 13, 2013
- Messages
- 25
So just looking for some pointers on this.
I recently moved my video collection from an old pool over via snapshot copy to a new one on the same machine. Old pool was a raidz1 of slow 2TB drives that were aging and starting to fail. New pool is raidz3 on faster 3TB drives. Nice increase in performance and I sleep better thanks to decent redundancy.
However, when playing the files on my media players (sharing is via SMB), I am seeing frequent, though not predictable, stalls in playback. This evidences itself as buffering (but there's no read activity going on) which occasionally results in the media player totally stopping playback. I would very occasionally see this on the old pool, however nowhere near as frequent. Watching a movie now this happens at least once, whereas previously it might be one in ten, or less. Playback stats show the buffer dries up and there's no data coming in. This happens seemingly at random during periods of no other load (as far as I can see at this stage).
Things I've tried so far:
Things changed recently:
At this stage I'm just looking for ideas on what could be happening and any suggestions on how to go about diagnosing and fixing?
I recently moved my video collection from an old pool over via snapshot copy to a new one on the same machine. Old pool was a raidz1 of slow 2TB drives that were aging and starting to fail. New pool is raidz3 on faster 3TB drives. Nice increase in performance and I sleep better thanks to decent redundancy.
However, when playing the files on my media players (sharing is via SMB), I am seeing frequent, though not predictable, stalls in playback. This evidences itself as buffering (but there's no read activity going on) which occasionally results in the media player totally stopping playback. I would very occasionally see this on the old pool, however nowhere near as frequent. Watching a movie now this happens at least once, whereas previously it might be one in ten, or less. Playback stats show the buffer dries up and there's no data coming in. This happens seemingly at random during periods of no other load (as far as I can see at this stage).
Things I've tried so far:
- Copying files that aren't cached from the volume. Solid, consistent reads, verified by watching zpool iostat -v, reports tab in the GUI, network traffic etc. I am confident there isn't an issue here given we're talking about, on average 4-6GB files over a 2 hour period, and I can see the pool sustaining 100MB/s+ sequential reads when copying. Network (all gigE) seems to sustain this fine too, so I don't think it's a network issue either.
- Different media players. Two separate linux based OpenElec builds, on two physically separate PC's on separate (wired) network runs, and an Android based Kodi install.
- All new disks were burnt in before use (long, destructive smart tests) and still check out fine.
- System generally seems ok. It's a dual quad core Xeon X5570 2.9Ghz box with 48GB ram that's very lightly loaded. Old, but it's not really doing anything difficult.
- SMB shares are created the same as previously. They have aio_pthread and streams_xattr set - but I only changed the path to the point to the new datastore, so these were set previously.
- * Pool is healthy, 53% used, no de-dupe, no compression, no encryption, no periodic (or any) snapshots, no L2ARC, ZIL etc. Bog standard. New pool was created via the GUI and the snapshots from the old pool copied over.
Things changed recently:
- New pool
- Updated to latest build on the 9.10.2 stable train (was on U5, now on U6)
At this stage I'm just looking for ideas on what could be happening and any suggestions on how to go about diagnosing and fixing?
