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>From: address@hidden >Organization: UCAR/Unidata >Keywords: 200407302213.i6UMDRLW023442 Hi Robert, Your email to the ldm-users email list regarding software RAID bounced since the email address you sent the inquiry from: address@hidden was not subscribed to the list. I just approved your subscriptions to the gembud, ldm-users, mcidas-x, pc-os, and nws-changes lists, so you could resend your inquiry if you like. Besides that, I have done a lot of investigation into use of software RAID under Linux on machines running the LDM. The last system I worked on not at the UPC was Gerry Creager's dual Xeon 2.4 Ghz machine that uses two HighPoint raid controllers (each has 4 IDE channels) and 8 Maxtor 250 GB (7200 RPM 2 MB cache) disks. After Gerry spent quite a bit of time trying to get hardware RAID to work correctly (i.e., the machine not crash), he came over to my way of thinking and tried software RAID. He played with several file systems on the RAID (ext3, jfs come to mind) before settling on ext2 even though it is not a journaling file system. He set the block size at 4 KB which I thought was too small, but the performance of the RAID has made me think otherwise. Gerry was also using his machine as an NFS server for awhile, but I don't know if he is doing that anymore. If you want to contact Gerry directly, his email address is: Gerry Creager n5jxs <address@hidden> Cheers, Tom >From address@hidden Fri Jul 30 16:13:26 2004 >Received: from uwxcom01.univ-wea.com (uwxcom01.univ-wea.com [12.31.213.84]) > by unidata.ucar.edu (UCAR/Unidata) with ESMTP id i6UMDPaW023436 > for <address@hidden>; Fri, 30 Jul 2004 16:13:25 -0600 (MDT) >Organization: UCAR/Unidata >Keywords: 200407302213.i6UMDPaW023436 >Received: from houmm.nt.univ-wea.com (houmm.univ-wea.com [12.31.213.144]) > by uwxcom01.univ-wea.com (8.12.10/8.12.10) with ESMTP id i6UMCma5027592 > for <address@hidden>; Fri, 30 Jul 2004 22:12:58 GMT >Received: from LIGHTNING.univ-wea.com (Not Verified[12.31.213.81]) by houmm.nt > .univ-wea.com with NetIQ MailMarshal (v5.5.6.7) > id <B00035b856>; Fri, 30 Jul 2004 17:12:48 -0500 >Received: by lightning.univ-wea.com with Internet Mail Service (5.5.2653.19) > id <3V0M5JC2>; Fri, 30 Jul 2004 17:06:24 -0500 >Message-ID: <address@hidden> >From: Robert Mullenax <address@hidden> >To: "'address@hidden'" <address@hidden> >Subject: LDM and SW RAID >Date: Fri, 30 Jul 2004 17:06:21 -0500 >MIME-Version: 1.0 >X-Mailer: Internet Mail Service (5.5.2653.19) >Content-Type: text/plain > >Could someone that is using software RAID on an LDM box that acts >as an NFS server e-mail offline? I have some performance questions. >Basically I am seeing very slow reads from a 5 disk stripe (16K) >on SW RAID 0 as compared to a single disk. > > >Thanks, >Robert Mullenax > -- NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publically available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us. >From address@hidden Sun Aug 1 10:51:08 2004 Thanks. Yes, ImpactWeather is now a subsidiary of Universal Weather..and I forgot that my e-mail changed. Thanks for making the changes. Gerry did contact me. I am using Solaris x86 9. Solaris has a minimum of 8kb stripe width. Once I lowered the stripe width to that, it seems to work fine. Gerry also mentioned the possibility of the bus being overloaded (5 disks on one controller (U320 SCSI)). I just have 3 disks in the stripe now...later I will make it 5 disks again with the 8kb stripes and test again. Sun stil doesn't support any modern HW RAID controllers on Solaris 9 x86..and I am starting to think they won't. They have show no interest in making that a priority. They would rather you buy their external storage that has RAID on the array. However, SOlaris 9 x86 has made a lot performance increases and 10 is even better (beta). The previous file system speed increase you saw wit Linux is gone. UFS+logging is very fast on Solaris now. Also, and you might pass this on to Steve, Sun has officially released their Studio 9 compilers which include a FORTRAN for Solaris x86. I have been using the beta version of these and have seen 30-60% performance increases over Linux and gcc/g77. Thank again, Robert