Vdbench and SSD alignment, continued.

Of course, it took only a few minutes before someone asked 'how can I run this against files, not volumes'. Here is the response:

Just change the lun to a file name (use the same file name each  time) and add a size.
Vdbench then will first create the file for you.
The problem will be that you need to make sure Vdbench will not read from file system or file server cache, so the file size must be at least 5 times the system's cache size,
Unless of course you mount stuff directio, but then you still have the file server cache to deal with.
Just take your time and create a large file (I am using 100g). Vdbench will automatically create it for you.

BTW: the elapsed time the elapsed time needs to be long enough to make sure you get away from cache. I set it here to 60 seconds, which should be a good start..

Henk.

hd=default,jvms=1
sd=default,th=32
sd=default,size=100g
sd=sd_0000,lun=/dir/filename,offset=0000
sd=sd_0512,lun=/dir/filename,offset=0512
sd=sd_1024,lun=/dir/filename,offset=1024
sd=sd_1536,lun=/dir/filename,offset=1536
sd=sd_2048,lun=/dir/filename,offset=2048
sd=sd_2560,lun=/dir/filename,offset=2560
sd=sd_3072,lun=/dir/filename,offset=3072
sd=sd_3584,lun=/dir/filename,offset=3584
sd=sd_4096,lun=/dir/filename,offset=4096
wd=wd1,sd=sd_1,xf=4k,rdpct=100
rd=default,iorate=max,elapsed=60,interval=1,dist=d,wd=wd1
rd=rd_0000,sd=sd_0000
rd=rd_0512,sd=sd_0512
rd=rd_1024,sd=sd_1024
rd=rd_1536,sd=sd_1536
rd=rd_2048,sd=sd_2048
rd=rd_2560,sd=sd_2560
rd=rd_3072,sd=sd_3072
rd=rd_3584,sd=sd_3584
rd=rd_4096,sd=sd_4096


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Blog for Henk Vandenbergh, author of Vdbench, and Sun StorageTek Workload Analysis Tool (Swat). This blog is used to keep you up to date about anything revolving around Swat and Vdbench.

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