Welcome to the most active Linux Forum on the web.
Go Back > Forums > Linux Forums > Linux - Newbie
User Name
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!


  Search this Thread
Old 05-27-2008, 12:48 PM   #1
Registered: Feb 2007
Posts: 386

Rep: Reputation: 30
sda sdb sdc drives not consistent

My company has a disk enclosers for 10 disks that can be used for RAID.
I am doing an experiment where i have only 3 disks in the slots.

After booting the linux machine and load the driver (for RAID pci card), I can see those 3 disks-- sda, sdb, and sdc-- using "fdisk -l"

I took sdb drive out of the tower, then call "fdisk -l".
Now I see only sda and sdc as expected.

Then i put the sdb back to the same slot and call "fdisk -l"
Now I see sda, sdc, and sdd.

Is this how it is supposed to work, or it is a bug of the RAID pci driver?
Old 05-27-2008, 12:53 PM   #2
LQ Addict
Registered: Jul 2002
Location: East Centra Illinois, USA
Distribution: Debian stable
Posts: 5,908

Rep: Reputation: 354Reputation: 354Reputation: 354Reputation: 354
I don't know if this makes a difference or not, but, did you unmount the partitions on sdb before removing it from the rack? Did you re-mount the partitions when you put it back in the rack, before running fdisk?
Old 05-27-2008, 03:35 PM   #3
Registered: Feb 2007
Posts: 386

Original Poster
Rep: Reputation: 30
No. I didn't umount any drive when taking it out of the rack since i try to simulate a disk failure. Plus, the tower say it support a hot swap.

When i put back the drive and see the sdc. I can probably mount /dev/sdd but i wonder why it does not detect the drive as sdb.
Old 05-27-2008, 04:44 PM   #4
LQ Addict
Registered: Jul 2002
Location: East Centra Illinois, USA
Distribution: Debian stable
Posts: 5,908

Rep: Reputation: 354Reputation: 354Reputation: 354Reputation: 354
Well, since it doesn't seem to be hot swapping quite as expected, perhaps a question sent to the vendor is in order.

As a test, try removing sdb to simulate disk failure. Then try taking the system down before re-inserting the drive. If it comes back as sdb, then you have evidence that the system isn't hot swappable as advertised.

You can either get a tower that works as advertised, or you should be able to get a partial refund for money paied in good faith for goods that don't live up to the advertisment.
Old 05-27-2008, 04:49 PM   #5
Registered: Apr 2008
Distribution: Arch
Posts: 36

Rep: Reputation: 15
I have a similar experience with usb sticks (the only thing that changes in my /dev) and i have noticed that it can mount sdc the first time and sdd the second (yes i'm mount-ing and umount-ing) maybe this is a problem with linux and not your hardware.
Old 05-27-2008, 04:53 PM   #6
LQ Guru
Registered: Nov 2004
Location: Saint Amant, Acadiana
Distribution: Gentoo ~arch
Posts: 6,317

Rep: Reputation: Disabled
Udev is assigning new device node, I'm not sure if using udev in a server is good idea at all. Plus, since Linux can see separate disk drives through your "RAID" controller then you obviously do not have hardware RAID. So the first question to answer here is what software RAID is in use?
Old 05-27-2008, 06:38 PM   #7
LQ Newbie
Registered: Apr 2006
Posts: 5

Rep: Reputation: 0
udev has some rules to make the device name to be persistent. You could find some pre-defined rules in SLES10. I think it might resolve this problem.


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Changing sda to sdb mickeyboa Fedora 4 04-21-2008 12:22 AM
New disk presentation allows sdb but not sda to be partitioned sbf132 Linux - Hardware 0 02-12-2008 07:21 PM
sda or sdb? stevest SUSE / openSUSE 7 12-18-2007 11:57 AM
cannot find sda or sdb for mounting pen drive in RH9 sakal_woman Linux - Hardware 3 11-20-2006 09:41 PM
zip drive alternately mounts on /sda and /sdb timsch75 Linux - Hardware 6 09-26-2004 10:00 AM > Forums > Linux Forums > Linux - Newbie

All times are GMT -5. The time now is 08:25 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration