Hi All, I'm currently working on a feasibility study of using Samba as video server which allows the MPEG videos on the Linux server to be mapped out as network drives on Window 98 clients, and then to select & play back these video files by multiple clients concurrently. My experiment so far showed smooth playback when the source MPEG is of about 450Kbits/s, beyond that I've tried MPEG of 1.2Mbits/s, and experienced delays during playback, i.e. a 5 minutes MPEG would take nearly 10 minutes to finish play, with jitters inbetween. The test of file copy from the Samba mapped drive to the Window's local disk showed about 1.2Mbits/s transfer rate. My samba installation is from the latest release, I've also edited the "smb.conf" to include most of the recommended tuning according the "Speed.txt" document included in the release. It looks like either some network configuration on either the Windows client side or the Linux side were not optimized, or that I'm having a crappy Linux box (it's a Compaq Presarrio 5522 with 64MB RAM, ...) Specific questions that I have are: 1. Using the "ifconfig" showed that my eth0 interface's MTU has maximum upper bound of 1500. When I changed the MTU down to 600, the samba transfer really slowed down terribly. So, I'd assume that getting improvement on MTU can help. Is it that I need to get a better Ethernet card to have a better MTU? Or that MTU 1500 is the limitation generic to Linux? 2. On the same clinet/server pair a ftp test showed about 2.2Mbits/s transfer rate, which is not too exciting either for the two only machines on a 10BaseT connection. Could it be that I'm having full/half duplex setting problem on either the Windows or the Linux side? How to check it out? 3. Or, the Linux server is simply too weak for it. I'd like to have the Linux Samba server serving up to 8 (eight) Windows clients for retrieving of MPEG-1 files (1.2Mbps to 1.5Mbps bit rate MPEG-1) CONCURRENTLY and hoping to have all 8 MPEG-1 files played back smoothly. Certainly I'd need to switch to 100BaseT support on the Linux box side, what about the CPU, RAM and disk configuration? Specifically: 3.1 How good should the CPU be? Would multiple CPU Linux help in this case? 3.2 What's the main memory minimal requirements? Considering the Samba supporting up to 8 concurrent clients? 3.3 RAID probably can help to improve the disk IO? Any recommendation on cost-effective RAID configuration for Linux for this purpose (I'd assume that RAID3 is good for large chunk mostly read-only)? My sincere thanks in advance for any kind advice on any of the above questions from anybody. Cheers, YJ Hong ---------------------- __________________________________________________ Do You Yahoo!? Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/
Dave Dezinski wrote: | We've got a few NT40 servers that have more than 20000 files | in a single directory, that don't perform this badly. We'd | like to replace these servers with Linux boxes using Samba, | but unless we re-organize these files into multiple directories | (which means a bunch of custom software needs to be rewritten), | this isn't possible. | | This definately is a problem that should be a looked into, this | is not the first time I've seen someone complain about this. Yes, it's an artifact of the Unix algorihms: linear search and the reliable writes of the directory metadata. The latter is adressed in the SGI logging filesystem, the Solaris logging option, ReiserFS and in ext2fs. | Spliting the files up into multiple directories, is just a | temporary workaround, not a solution. Well, it's sort of a permanent workaround (;-)) It adresses the linear-search problem nicely, which only a true logging fs (or caching) helps with. NT will run out of speed on very deep b-tree structures, which fortunately are rare, although programs generating filenames sometimes stumble into the "bad" part of the namespace. So would hashing filesystems, if anyone built them. --dave -- David Collier-Brown, | Always do right. This will gratify some people 185 Ellerslie Ave., | and astonish the rest. -- Mark Twain Willowdale, Ontario | //www.oreilly.com/catalog/samba/author.html Work: (905) 415-2849 Home: (416) 223-8968 Email: davecb@canada.sun.com