Disk Enclosures
cancel
Showing results for 
Search instead for 
Did you mean: 

Installing new OS on a DS20e with Raid8000/HSZ70

SOLVED
Go to solution
NoJ_1
Occasional Visitor

Installing new OS on a DS20e with Raid8000/HSZ70

Hi there (:

I'm trying to install a new OS onto disks located in an external Raid that uses an HSZ70-Controller. The problem is that the "performance" of the installation process is unacceptably slow. When unpacking the source files of the OS ( Gentoo Linux ) onto a disk in the disk-array, the operation at first runs quite fluently, then stops, runs again and so forth. This seemed to me that some kind of replication between the two disks in a mirrorset is performed, but the same keeps ocurring after trying it on a single, non-mirrored disk. An action like mke2fs on an 8GB partition takes approximately 10 minutes to finish. The disks themselves seem to be fine, since they performed normally when using them as storage-devices on an previous Tru64-System. Im currently working part-time on this besides my study and started reading through the manuals available on this but havent found an acceptable answer so far.
An installation of the same OS on the internal disks worked out just fine.
Any hints about reasons that might cause this situations are appreciated.

Thanks in advance,

NoJ
4 REPLIES
Uwe Zessin
Honored Contributor

Re: Installing new OS on a DS20e with Raid8000/HSZ70

Unfortunately, neither "is unacceptably slow" nor "mke2fs on an 8GB partition takes approximately 10 minutes to finish" gives much useful information to find out if there really is a problem.

How much data does the 'mke2fs' write?

The HSZ70 is a Ultra-SCSI (40 MegaBytes / second) front- and back-end, but I usually don't see more than 10 MegaBytes/s to a single disk on HSZ/HSG controllers.

If 'mke2fs' really writes 8 Gigabytes, then this is about 13.3 MegaBytes/s - a realistic value according to my experience.

You can check if the unit(s) have WRITEBACK_CACHE enabled.
HSZ> show units full

It's been some time that I worked with a HSZ70, but if I recall correctly, it's default is OFF.
.
NoJ_1
Occasional Visitor

Re: Installing new OS on a DS20e with Raid8000/HSZ70

Mke2fs doesnt write 8GB of data, it just creates the structure of the filesystem. I told that value since, as you already pointed out, I dont have any other usefull information.
Copying an archive of ~100MB to the disk through the network works fine, but when unpacking this archive, the previous mentioned error ( write->freeze->write->freeze ... ) occurs. The archive is unpacked using tar with -v options so I can see the "running" and "frozen" process. The WRITEBACK_CACHE switch is enabled ( if the show units full command only shows those switches that are enabled ).
Two other values that might help to understand the used phrase "unaccaptable":
mounting a partition on the disk takes ~5mins, "ls" of a folder stored on the disk takes between 30sec and up to 5 minutes ( if the disk is "frozen" ).


Uwe Zessin
Honored Contributor
Solution

Re: Installing new OS on a DS20e with Raid8000/HSZ70

OK, that makes sense to me, now - thanks!

Have you checked the host compatibility setting? I don't know if Linux was ever supported on the HSZ70, so I would try it with F (SUN Solaris) or E (Silicon Graphics, IRIX).

HSZ> set this_controller host_function=F

After that, restart the controller.
.
NoJ_1
Occasional Visitor

Re: Installing new OS on a DS20e with Raid8000/HSZ70

Thank you for the hint Uwe!

With the HOST_FUNCTION set to F the disks work fine now.

I wish you a nice weekend,

NoJ