Hi, We recently bought 3 new Dell 860 servers with the onboard SAS5/IR SATA RAID-controller. They seem to be quite well spec'ed servers with management and everything - but I am experiencing av major performance issue with the disc i/o. On write I get at max 7-8MB/sec, while read gives a bit more (11MB/sec). I tried first with 6.2-RELEASE, and then upgraded to 6.3-PRERELEASE without any better results. I am aware of some discussion around this issue on these two maillists in the spring earlier on this year, but I have not been able to find any good resolution. My old firewall/router at home equipped with a 733Mhz Pentium 3 processor and a old 40GB IDE harddrive made around year 2001 performe better. Is there anybody out there with the same problem who has solved this issue? Could it be that this is solved in 7.0? Thanks in advance. -- med vennlig hilsen/with regards, Espen Tagestad Modula AS Tel. (+47) 23 89 75 80 Mob. (+47) 92 44 50 12 Fax. (+47) 23 89 75 81
Espen Tagestad wrote:> Hi, > > We recently bought 3 new Dell 860 servers with the onboard SAS5/IR SATA > RAID-controller. They seem to be quite well spec'ed servers with > management and everything - but I am experiencing av major performance > issue with the disc i/o. On write I get at max 7-8MB/sec, while read > gives a bit more (11MB/sec). I tried first with 6.2-RELEASE, and then > upgraded to 6.3-PRERELEASE without any better results. > > I am aware of some discussion around this issue on these two maillists > in the spring earlier on this year, but I have not been able to find any > good resolution. My old firewall/router at home equipped with a 733Mhz > Pentium 3 processor and a old 40GB IDE harddrive made around year 2001 > performe better. Is there anybody out there with the same problem who > has solved this issue? Could it be that this is solved in 7.0? > > Thanks in advance. >You haven't indicated what drives are on that controller, or how (RAID?) arranged.,, what sort of on-drive or on-controller cahce and policy. Nor how you measured the '..performs better', which a single <anything> can often do compared to several of the possible RAID configurations. Otherwise, those are not actually 'bad' numbers for sustained I/O - especially if anything-at-all is going on at the same time that needs to intervene and move the r/w heads 'elsewhere' - however briefly. More info? Bill
Espen Tagestad wrote:> Hi, > > We recently bought 3 new Dell 860 servers with the onboard SAS5/IR SATA > RAID-controller. They seem to be quite well spec'ed servers with > management and everything - but I am experiencing av major performance > issue with the disc i/o. On write I get at max 7-8MB/sec, while read > gives a bit more (11MB/sec). I tried first with 6.2-RELEASE, and then > upgraded to 6.3-PRERELEASE without any better results. > > I am aware of some discussion around this issue on these two maillists > in the spring earlier on this year, but I have not been able to find any > good resolution. My old firewall/router at home equipped with a 733Mhz > Pentium 3 processor and a old 40GB IDE harddrive made around year 2001 > performe better. Is there anybody out there with the same problem who > has solved this issue? Could it be that this is solved in 7.0? > > Thanks in advance. >Hi, If you have sata disks on this controller you will need to run RELENG_6 dated after 2007-06-05 21:32:57. You will also need to set the hw.mpt.enable_sata_wc sysctl in loader.conf. Here is Scott Long's commit log of the changes that 'fix' this issue. Tom Commit Message: scottl 2007-06-03 23:13:05 UTC FreeBSD src repository Modified files: sys/dev/mpt mpt.c mpt.h mpt_cam.c Log: mpt.c: mpt.h: Add support for reading extended configuration pages. mpt_cam.c: Do a top level topology scan on the SAS controller. If any SATA device are discovered in this scan, send a passthrough FIS to set the write cache. This is controllable through the following tunable at boot: hw.mpt.enable_sata_wc: -1 = Do not configure, use the controller default 0 = Disable the write cache 1 = Enable the write cache The default is -1. This tunable is just a hack and may be deprecated in the future. Turning on the write cache alleviates the write performance problems with SATA that many people have observed. It is not recommend for those who value data reliability! I cannot stress this strongly enough. However, it is useful in certain circumstances, and it brings the performence in line with what a generic SATA controller running under the FreeBSD ATA driver provides (and the ATA driver has had the WC enabled by default for years).
We've had the same performance issues with the 860's (not just on BSD). We contacted Dell support and they suggested to download the Linux Dell Rescue CD, and enable the cache policy on the Virtual Disk on the controller. You can download the rescue CD here: http://linux.dell.com/monitoring.shtml You have to disable all OMSA tools when the CD is booted (icon on desktop), after which you can start the LSI SAS Raid manager. After starting just click the virtual disk and go to "set properties" or something. We tried that on a BSD system, and this resolved the issue for us (now over 50MB/sec. seq. write). Regards, Ruben van der Zwan Espen Tagestad wrote:> Hi, > > We recently bought 3 new Dell 860 servers with the onboard SAS5/IR > SATA RAID-controller. They seem to be quite well spec'ed servers with > management and everything - but I am experiencing av major performance > issue with the disc i/o. On write I get at max 7-8MB/sec, while read > gives a bit more (11MB/sec). I tried first with 6.2-RELEASE, and then > upgraded to 6.3-PRERELEASE without any better results. > > I am aware of some discussion around this issue on these two maillists > in the spring earlier on this year, but I have not been able to find > any good resolution. My old firewall/router at home equipped with a > 733Mhz Pentium 3 processor and a old 40GB IDE harddrive made around > year 2001 performe better. Is there anybody out there with the same > problem who has solved this issue? Could it be that this is solved in > 7.0? > > Thanks in advance. >