Tech Stuff

Did some benchmarking on the UFies.org box (see the system specs here) to see if the nice 18G Seagate Cheetah drive, with an 8meg cache, compares to 4 Maxtor 40G drives in a RAID5 configuration, each with a pretty decent speed itself? Does SCSI win? Whose drive reigns supreme?

Sorry, slipped into Iron Chef mode for a moment there.

Running hdparm tests on the SCSI drive (/dev/sda) and an individula (non-RAID) IDE drive (/dev/hde) gave me the following results for three separate runs:

Run #1

/dev/sda:

Timing buffer-cache reads:   128 MB in  0.79 seconds =162.03 MB/sec

Timing buffered disk reads:  64 MB in  2.10 seconds = 30.48 MB/sec

/dev/hde:

Timing buffer-cache reads:   128 MB in  0.69 seconds =185.51 MB/sec

Timing buffered disk reads:  64 MB in  1.74 seconds = 36.78 MB/sec

/dev/sda:

Timing buffer-cache reads:   128 MB in  0.56 seconds =228.57 MB/sec

Timing buffered disk reads:  64 MB in  2.48 seconds = 25.81 MB/sec

/dev/hde:

Timing buffer-cache reads:   128 MB in  0.55 seconds =232.73 MB/sec

Timing buffered disk reads:  64 MB in  1.60 seconds = 40.00 MB/sec

/dev/sda:

Timing buffer-cache reads:   128 MB in  0.57 seconds =224.56 MB/sec

Timing buffered disk reads:  64 MB in  2.28 seconds = 28.07 MB/sec

/dev/hde:

Timing buffer-cache reads:   128 MB in  0.57 seconds =224.56 MB/sec

Timing buffered disk reads:  64 MB in  1.60 seconds = 40.00 MB/sec

After this I ran bonnie on the filesystem to test it. Bonnie not only takes into account the speed of data being moved around the disk, but also of the amount of CPU that it takes to move it. A page with how to interpret the bonnie results is here.

First for the RAID5 setup (/var) the command line was:

bonnie -d /var/tmp -s 1g -n master -r 512MB -u nobody:nogroup -f

And the results:

Version 1.02c       ——Sequential Output—— –Sequential Input- –Random-

-Per Chr- –Block– -Rewrite- -Per Chr- –Block– –Seeks–

Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP

master           1G           22414  19  6959   9           11243   5  67.2   0

——Sequential Create—— ——–Random Create——–

-Create– –Read— -Delete– -Create– –Read— -Delete–

files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP

16   958  90 +++++ +++ +++++ +++  1095  96 +++++ +++  5052  94

Then I tested the SCSI disk (/) the command line was:

bonnie -d /home/tmp -s 1g -n master -r 512MB -u nobody:nogroup -f

And the results:

Version 1.02c       ——Sequential Output—— –Sequential Input- –Random-

-Per Chr- –Block– -Rewrite- -Per Chr- –Block– –Seeks–

Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP

master           1G           19167  20  7908   6           16688   6 298.5   1

——Sequential Create—— ——–Random Create——–

-Create– –Read— -Delete– -Create– –Read— -Delete–

files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP

16 15163  99 +++++ +++ 12388  99 14929 100 +++++ +++  7521  67

Basically from what I understand of bonnie, both disks (well, the SCSI vs the RAID) were pretty close, with each edging out the other on various tests.

Just for fun I also ran this test with the same parameters (except for the ram size) on this system, which has RAID0 SCSI, but old SCSI 🙂

Version 1.02c       ——Sequential Output—— –Sequential Input- –Random-

-Per Chr- –Block– -Rewrite- -Per Chr- –Block– –Seeks–

Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP

naked.arcterex.n 1G            9458  45  4492   9           10433   9  89.5   1

——Sequential Create—— ——–Random Create——–

-Create– –Read— -Delete– -Create– –Read— -Delete–

files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP

16   296  96 +++++ +++ 19496  99   314  98 +++++ +++  1199  80