Andrew/Ard-
Could you indicate which Mylex board you are using?
I'm interested in implementing a mirror solution (w RedHat 6.0 or 6.1) RAID
1
and was looking into a Mylex SCSI card to support the configuration (PCI
based SCSI to external SCSI) platform. It appears your using a single
channel solution with s/w RAID.
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of [EMAIL PROTECTED]
Sent: Monday, December 06, 1999 11:38 AM
To: Andrew Ryan
Cc: Ard van Breemen; [EMAIL PROTECTED]
Subject: Re: MegaRAID vs Mylex
On Mon, Dec 06, 1999 at 10:04:11AM -0600, Andrew Ryan wrote:
> On Sun, Dec 05, 1999 at 06:58:35PM +0100, Ard van Breemen wrote:
> > Linux averages about 20 MB/s reading and writing raid 5 with 3
> > scsi-disks using the ncr53c8xx driver for the sym53c895.
> > raid-1 on the ami and the mega averages about 2.5MB/s to 3MB/s.
> > The myles is not much faster.
> Have you tried changing the write mode in the megaraid setup? The default
> mode is the "safe" write mode. If you change it to the "unsafe" (if you
> have a UPS it isn't unsafe) it should help your speed. I can't remember
the
> wording for the option.
Yep, but it is not really helpful for a logging filesystem I guess...
It defeats the purpose, and that for only a 17% write speed increase.
as I promised, some stats:
pc=Some siemens server with 128MB's of ram.
ami=express-200 or something like that (466)
Mylex is comparable. Both 16MB of ram.
solaris==solaris 7 x86. Linux == rh61 install disk
ncr=53c895
============================================================================
====
solaris raid-5 ami
----------------------------------------------------------------------------
----
File './Bonnie.2981', size: 419430400
-------Sequential Output-------- ---Sequential
Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per
Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
%CPU
400 2371 12.3 2587 5.3 2098 5.8 14183 84.4 13345 15.6 212.9
4.7
============================================================================
====
solaris/mylex/raid 5
----------------------------------------------------------------------------
----
/backup/bonnie > /Bonnie/Bonnie -s 200
-------Sequential Output-------- ---Sequential
Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per
Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
%CPU
200 2025 9.6 2030 3.3 678 1.6 13634 80.1 19388 22.7 201.7
2.6
============================================================================
====
solaris/mylex/raid 1
----------------------------------------------------------------------------
----
File './Bonnie.453', size: 209715200
-------Sequential Output-------- ---Sequential
Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per
Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
%CPU
200 3619 17.4 3876 7.2 477 1.2 10947 64.3 13978 19.0 113.1
2.0
============================================================================
====
solaris/ami/raid 1
----------------------------------------------------------------------------
----
File './Bonnie.416', size: 419430400
-------Sequential Output-------- ---Sequential
Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per
Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
%CPU
400 3237 15.5 3936 6.4 4165 10.8 11991 70.3 10816 12.6 206.0
3.9
============================================================================
====
solaris/ami controller/raid 1
write back option turned on
----------------------------------------------------------------------------
----
File './Bonnie.603', size: 419430400
-------Sequential Output-------- ---Sequential
Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per
Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
%CPU
400 4114 19.8 4697 7.9 3862 10.5 10224 59.8 8376 10.6 186.6
3.4
============================================================================
====
linux/mylex/raid 1 RH61 install media
"mke2fs -b 4096 -R stride=16 /dev/rd/c0d0" (Geen partitionering)
----------------------------------------------------------------------------
----
File './Bonnie.46', size: 209715200
-------Sequential Output-------- ---Sequential
Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per
Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
%CPU
200 5287 73.5 5173 4.2 2926 5.9 6092 77.3 14655 8.4 349.6
3.5
============================================================================
====
linux/NCR controller/software raid 5 RH61 install media
"mke2fs -b 4096 -R stride=8 /dev/md0" (Geen partitionering)
(During rebuild of the raiddevice, 200Meg Bonnie)
----------------------------------------------------------------------------
----
File './Bonnie.65', size: 209715200
-------Sequential Output-------- ---Sequential
Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per
Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
%CPU
200 6220 87.2 20083 17.1 7723 17.6 6855 88.9 21344 13.0 399.6
4.2
============================================================================
====
linux/NCR controller/software raid 5 RH61 install media
"mke2fs -b 4096 -R stride=8 /dev/md0" (Geen partitionering)
(During rebuild of the raiddevice, 400Meg Bonnie)
----------------------------------------------------------------------------
----
-------Sequential Output-------- ---Sequential
Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per
Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
%CPU
400 6007 84.1 18349 16.1 7769 16.6 7172 92.5 21491 14.4 230.1
2.4
============================================================================
====
linux/NCR controller/software raid 5 RH61 install media
"mke2fs -b 4096 -R stride=8 /dev/md0" (Geen partitionering)
(After rebuild of the raiddevice, 400 Meg Bonnie)
----------------------------------------------------------------------------
----
File './Bonnie.162', size: 419430400
-------Sequential Output-------- ---Sequential
Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per
Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
%CPU
400 6049 84.4 18215 15.5 7776 17.1 7192 93.2 21577 13.4 232.9
2.8
============================================================================
====
Resultaten:
linux/NCR controller/software raid 1 RH61 install media
"mke2fs -b 4096 -R stride=8 /dev/md0" (Geen partitionering)
(During rebuild of the raiddevice, 400Meg Bonnie)
----------------------------------------------------------------------------
----
File './Bonnie.51', size: 419430400
-------Sequential Output-------- ---Sequential
Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per
Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
%CPU
400 6676 94.4 15419 13.9 6566 13.8 7238 92.8 14684 10.1 195.3
2.4
----------------------------------------------------------------------------
----
Note: these figures are not good enough to base your choice of
raidcontroller
on. And no, they should not be used as an authoritive test. Just look at the
numbers and think about them.
These are my conclusions:
1) software raid-5 with linux is definitely MUCH faster. Especially when we
realize that the rh61 install media uses the ncr53c8xx driver, and not the
sym53c8xx driver.
2) solaris ufs versus linux ext2...
My personal conclusion:
mylex and ami raid controllers have about the same performance.
Both have their pro's and con's. We choose ami as our first raid controller,
because at first it seemed to be the best supported for configuring empty
raid-controllers from within solaris. Myles is still on our list, but will
be worked on in the future as our second source.
(And, ehhhh, we use linux to install solaris :))), try booting solaris from
a cd...).
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