I am having a problem with performance of the drive system on a Debian "Lenny" distro. This is running RAID under mdadm with a reiserfs file system on a raw partition. The kernel is 2.6.26-1-amd64 running on an AMD Athlon 64 x 2 CPU with 4G of RAM. Ordinarily, performance is quite good, and I have transferred files as fast as 480 Mbps upon occasion. Frequently, however, drive access will drop to dead zero for about 40 seconds. The trigger event seems to be file creation, and I don't believe it usually happens unless a file is being created. It does not happen every time a file is created, but for example I have a script which performs a number of tests and checks and at the end creates a log file. When the script reaches that point, it often hangs, and if there are any network file transfers going on in the background (there usually are), the network utilization drops right off to almost zilch. Another common trigger is editing a video on one of the served Windows workstations. At some point the edit parameters are saved in a cut file. When the user first selects the "Save Project" utility, the file write often hangs for about 40 seconds. Sometimes Windows will report the drive is full, or a timeout has occurred. I do not know for a fact that drive - drive transfers are suspended, but NFS, SAMBA, FTP, and other network transfers in both directions are abrupted for a period of about 40 seconds. Non-drive related transfers, or transfers to devices other than the RAID array are not impacted. There is nothing in any of the logs to suggest anything at all has happened. Interestingly enough, although Windows sometimes complains, ordinary TCP transfers do not time out, despite the fact not a single byte transfers in either direction during the event.
What can I do to try to find out what is hanging and why? --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Linux Users Group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] For more options, visit our group at http://groups.google.com/group/linuxusersgroup -~----------~----~----~----~------~----~------~--~---
