Asif Iqbal wrote: > On Nov 19, 2007 11:47 PM, Richard Elling <[EMAIL PROTECTED]> wrote: > >> Asif Iqbal wrote: >> >>> I have the following layout >>> >>> A 490 with 8 1.8Ghz and 16G mem. 6 6140s with 2 FC controllers using >>> A1 anfd B1 controller port 4Gbps speed. >>> Each controller has 2G NVRAM >>> >>> On 6140s I setup raid0 lun per SAS disks with 16K segment size. >>> >>> On 490 I created a zpool with 8 4+1 raidz1s >>> >>> I am getting zpool IO of only 125MB/s with zfs:zfs_nocacheflush = 1 in >>> /etc/system >>> >>> Is there a way I can improve the performance. I like to get 1GB/sec IO. >>> >>> >> I don't believe a V490 is capable of driving 1 GByte/s of I/O. >> > > Well I am getting ~190MB/s right now. I sure not hitting any where close > to that ceiling > > >> The V490 has two schizos and the schizo is not a full speed >> bridge. For more information see Section 1.2 of: >> http://www.sun.com/processors/manuals/External_Schizo_PRM.pdf >>
[err - see Section 1.3] You will notice from Table 1-1, the read bandwidth limit for a schizo PCI leaf is 204 MBytes/s. With two schizos, you can expect to max out at 816 MBytes/s or less, depending on resource contention. It makes no difference that a 4 Gbps FC card could read 400 MBytes/s, the best you can do for the card is 204 MBytes/s. 1 GBytes/s of read throughput will not be attainable with a V490. -- richard _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
