Hi, We've got a setup here with a samba server in front of a fibrechannel array. It's a pretty vanilla samba setup exporting an xfs filesystem. The box is an opteron 265 with 4G RAM and a QLogic QLA2312 HBA running SLES9. We can dd an 8G file to a share from a windows workstation in just over 2 minutes (about 65MB/s) and dd back in about 4 minutes. Local disk performance in the machine gives about 195MB/s to disk and 120MB/s from disk. The problem comes when trying to capture video using Adobe Premiere 6.5 and write straight to the share - we get a *lot* of dropped frames (somewhere in the region of 25%+). Yet the same job to an Adaptec Snap server (which is samba on adaptec's guardianOS) works fine, even through it can only sustain 10MB/s. Any ideas would be much appreciated. Best regards, --Matt London Alliance Technologies Tel: (416) 385 3255 x232 Fax: (416) 385 1774
On Wed, Apr 19, 2006 at 05:31:50PM -0400, Matt London wrote:> Hi, > > We've got a setup here with a samba server in front of a fibrechannel array. It's a pretty vanilla samba setup exporting an xfs filesystem. > > The box is an opteron 265 with 4G RAM and a QLogic QLA2312 HBA running SLES9. > > We can dd an 8G file to a share from a windows workstation in just over 2 minutes (about 65MB/s) and dd back in about 4 minutes. > > Local disk performance in the machine gives about 195MB/s to disk and 120MB/s from disk. > > The problem comes when trying to capture video using Adobe Premiere 6.5 and write straight to the share - we get a *lot* of dropped frames (somewhere in the region of 25%+). Yet the same job to an Adaptec Snap server (which is samba on adaptec's guardianOS) works fine, even through it can only sustain 10MB/s. >Well it's the same codebase so it should be just as fast :-). Firstly, what version of Samba are you running ? Secondly, what do you have in your smb.conf ? Jeremy.
On Wed, Apr 19, 2006 at 05:31:50PM -0400, Matt London wrote:> The problem comes when trying to capture video using Adobe > Premiere 6.5 and write straight to the share - we get a > *lot* of dropped frames (somewhere in the region of 25%+). > Yet the same job to an Adaptec Snap server (which is samba > on adaptec's guardianOS) works fine, even through it can > only sustain 10MB/s.There are a lot of variables here that need quite thorough testing. Does Adobe Premiere write a single big file? If it does, what is the write performance that you get with for example xcopy or a copy by explorer. This gives you some indication, but it is by no means the full story. Next step in analyzing this is watching the *exact* pattern of write calls that Adobe Premiere uses and look for latencies there. Even the network card drivers can have a big influence on a workload like that, also fibre channel is not always the silver bullet that people believe it is. FC drivers can also introduce stalls that influence streaming performance. Lots of diagnosis work for you I'm afraid. Volker -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: not available Url : http://lists.samba.org/archive/samba/attachments/20060420/67f1099b/attachment.bin