Hi Roger / All -- ls -la -rw-r--r-- 1 root root 8130652160 2008-04-08 11:07 sys.dump dd if=sys.dump of=/dev/null 15880180+0 records in 15880180+0 records out 8130652160 bytes (8.1 GB) copied, 28.5627 s, 285 MB/s I did the test you recommend and got the above. I think I could come close to flooding that interface. I was looking at the: http://www.newegg.com/Product/Product.aspx?Item=N82E16816103066 $200.00 (1) Adaptec 2250300-R PCIe x 1 SCSI 29320LPE Kit - new scsi card to increase bandwidth on lto4 tape system. (my current card is U160/133 pci-x, but i have a PCIe x 1 free) I haven't found any major problems searching the web on this card. Do you have a recommendation on a LSI card? Thanks much for all you input, I'm mostly a lurker of the list, but I've learned mucho and keep reading and learing! -- Gary > > Hi Roger -- > > > > Thanks for the quick responses. The backup unit is a Overland arcvault > > 12 w/lto4 drive. The lto4 have, > > I think, 120MBps (Native)/240MBps (compressed), so no gain using U320 > > interface? I'd guess the max thru put > > would be 120MBs, with the compressed rate just accomplished because of > > data compressing. Sorry to > > be thinking out loud here, but this does help! > > > > > > -- G > > > > Well, if that is what you have, you did spend some decent money on it. > > The important part it LTO4. Native speed is 432GB/hr, or 120MB/second, if you > get good compression and you have a *FAST* disk subsystem, then you could use > that speed, I would test doing a backup with you backup software to /dev/null > and see what the actual disk speed is, if you are backing up a lot of small > files you won't be able to use all of the speed, or if the files are fragmented > on disk you may not be able to use that speed. > > If you data does not compress good you won't be able to go over 160 MB/second > either. > > You would have to be getting the data locally from a high-end disk subsystem, > and you have to have big files, and you would have to data that was > compressible. Overall you have to be pretty careful to get something that > will read at 120MB/second and also write out to a tape at 120MB/second, you have > to make sure the PCI-X slots are not shared with each other, and that all other > subsystems can do it. > > And if your current SCSI card is PCI (not-X, not-64bit) then the actual limit > is probably < 132MB/sec (PCI limit). > > I would try what you have and see what speed you are getting, if you run within > 20-30 of the limit you may be hitting the limit, if you are much below that you > have other issues. > > Generally though I have had good luck with the LSI cards, I have used their > SCSI, SAS, and fiber channel cards of various sorts. If I was getting one of > those new I would have got either a SAS or a Fiber channel interface for it (if > it was available), as they tend to be less trouble than SCSI. > > Roger > > > > > > ------------------------------ > -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list
