Re: Raidtest/3Ware 6000 Throughput
Don O'Neil wrote: [ ... ] Does this seem accurate? Should I only be seeing 4.7 MB/second throughput or is raidtest just not a good way to measure peak throughput? Any thoughts would be appreciated. It does not astonish me that you get 5 MB/s on a RAID-5 config, although if you used SCSI and/or a real HW RAID-5 controller with significant cache (ie, 64+ MB) that would help the performance by quite a bit. Use RAID-5 for read-only or read-mostly situations and you'll be better off; use RAID-10 for write-heavy filesystems instead. -- -Chuck ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
RE: Raidtest/3Ware 6000 Throughput
Chuck, Thanks... That is the intention of the filesystem, it is going in a web server. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Swiger Sent: Thursday, March 16, 2006 5:43 AM To: Don O'Neil Cc: freebsd-questions@freebsd.org Subject: Re: Raidtest/3Ware 6000 Throughput Don O'Neil wrote: [ ... ] Does this seem accurate? Should I only be seeing 4.7 MB/second throughput or is raidtest just not a good way to measure peak throughput? Any thoughts would be appreciated. It does not astonish me that you get 5 MB/s on a RAID-5 config, although if you used SCSI and/or a real HW RAID-5 controller with significant cache (ie, 64+ MB) that would help the performance by quite a bit. Use RAID-5 for read-only or read-mostly situations and you'll be better off; use RAID-10 for write-heavy filesystems instead. -- -Chuck ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED] ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
RE: Raidtest/3Ware 6000 Throughput
I would have thought I would at least see the raw single drive throughput, plus maybe a bit more. I've benched these drives independantly at 20+ MB/second... Is the 3ware card really slowing things down that much with the RAID-5 overhead? What real HW RAID-5 controller would you suggest? I'd like to stick with IDE/ATA since I have a bunch of drives already. Am I maybe CPU bound, or have another issue? -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Swiger Sent: Thursday, March 16, 2006 5:43 AM To: Don O'Neil Cc: freebsd-questions@freebsd.org Subject: Re: Raidtest/3Ware 6000 Throughput Don O'Neil wrote: [ ... ] Does this seem accurate? Should I only be seeing 4.7 MB/second throughput or is raidtest just not a good way to measure peak throughput? Any thoughts would be appreciated. It does not astonish me that you get 5 MB/s on a RAID-5 config, although if you used SCSI and/or a real HW RAID-5 controller with significant cache (ie, 64+ MB) that would help the performance by quite a bit. Use RAID-5 for read-only or read-mostly situations and you'll be better off; use RAID-10 for write-heavy filesystems instead. -- -Chuck ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED] ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Raidtest/3Ware 6000 Throughput
Don O'Neil wrote: I would have thought I would at least see the raw single drive throughput, plus maybe a bit more. When choosing RAID levels, you are making a tradeoff between performance, reliability, and cost. Choosing RAID-5 means you value performance the least of the three: If you prefer... ...consider using: --- performance, reliability:RAID-1 mirroring performance, cost: RAID-0 striping reliability, performance:RAID-1 mirroring (+ hot spare, if possible) reliability, cost: RAID-5 (+ hot spare) cost, reliability: RAID-5 cost, performance: RAID-0 striping If you've got enough drives, using RAID-10 or RAID-50 will also improve performance compared to stock RAID-1 or RAID-5 modes. I've benched these drives independantly at 20+ MB/second... Is the 3ware card really slowing things down that much with the RAID-5 overhead? Yes. It will be less noticeable with big transactions, and more noticeable with lots of tiny ones. What real HW RAID-5 controller would you suggest? I'd like to stick with IDE/ATA since I have a bunch of drives already. Maybe the 3ware 9500S -4 or -8...? Am I maybe CPU bound, or have another issue? You're probably I/O bound, not CPU bound. -- -Chuck ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
