Topic: From softwareMirroring to single install

[Alex]

Hi
I have just a software mirror sme5.5 and i want to switch to a single install

Have i  to do a fresh install, or can i do an upgrade?

Or is it possible to take one hdd out of the system without loosing data?
 
Did anyone tested this?

Thanks
Alex

[Nathan Fowler]

Just take one of the HDD's out of the system, it'll act as a broken RAID-1 array and you won't lose data (Isn't that the point of RAID-1 after all?  If one drive fails the other continues to operate).

Hope this helped,
Nathan

[Alex]

Thank you!

Just one more question:

Is the system so fast as a single install, after taking off a hdd ? Thats the reason, why i want to go back to single drive!

[Nathan Fowler]

No, you won't notice any increase in speed.  The CPU overhead for RAID-1 calculations aren't very high at all, and unless you have both disks on the same IDE channel you won't notice a speed increase in drive throughput.

Hope this helped,
Nathan

[Alex]

I tried the mirroring just one day! And while copying files to sme I was not able to listen to mp3 wich are saved on sme, and the switch doesnt showed me a lot of traffic, only hdd' LED on sme is all teh time on.

The Hdd are not on the same ide channel.

[Alex]

Ok i have now an single drive install again
and it is much faster than as mirrored!

Thank you for your help!

AleX

[Nathan Fowler]

Wow, you must have a slow box.  I've got two 5400 RPM 1.2GB Quantum drives in a P2-300Mhz and I have very little CPU over-head and very little Disk I/O and bottle-necks.

I'm also doing almost constant Disk I/O on that box due to the webserver, mail server, and cron jobs.

Glad it's working fast for you.

Nathan

[Alex]

That box isnt so slow :
AMD XP1800
 512MB RAM
7200 rpm 120GB IBM
But in mirror mode it was so slow, i was wondering my self


ALeX

[Michael Smith]

If you only tried the mirroring for one day, it probably never finished the software mirror, so the machine was busy.  I bet if you'd waited a day or so the system would've returned to a higher performance level.  As pointed out earlier, you DID have the drives as masters on separate IDE channels, correct?

[Alex]

Yes every hdd was a master hdd on seperate channel and no other devices on each ide-channel.

But if i didn't copied something hdd led was off, so the mirroring must be finished.

Alex

[Nathan Fowler]

You can always check on the status of your RAID array by viewing the contents of /proc/mdstat:

cat /proc/mdstat

[UU] means the partitions are uniform.

[Alex]

Thank you for your help! I will try it, when i will have an test server again!

AleX

[Lowell]

Looking at Michael Smith's response, If I don't have any thing else on a cable, where would I put the CD rom?
My mirror ends up showing my 15 gig drives as 6.3 gig.