Questions related to RHEL4

[Morcos]

Hello,
I'm used to RHEL3, and I'm doing some tests on RHEL4. I installed the RHEL4 with "minimum packages" as I did usually with version3:
1) I tried to extend a filesystem with the command e2fsadm, but I'm getting: command not found, so what's the equivalent of e2fsadm or what's the procedure to do on RHEL4 to resize a file system.
2)Also I log on as root, and did a crontab using crontab -e, I wanted the result to be sent to another user changing MAILTO=myuser but the email wasn't sent to this user, so how to proceed.
3)Also how to do a software raid, on RHEL3 there was the command mkraid and there's the file /etc/raidtab, but here how to proceed.

I'll be thankfull for any help and thanks in advance.
Ziad

[Steven E. Protter]

Shalom,

As far as I know software raid didn't change much from RHEL3 to 4.

Note that on a cold install of RHEL ES 4 the initial release, you could not boot off the software raid. You get a no operating system warning from the system.

This is a bug and i recommend you use update 2.

SEP

[Sergejs Svitnevs · Accepted solution]

1) To extend a filesystem, you need:

a) Create new physical volume (if not created)
# pvcreate /dev/hdaX

b) Add the newly created partition (hdaX) to Volume Group vg0Y
# vgextend vg0Y /dev/hdaX

c) Resize logical volume
# lvextend -l+ /dev/vg0Y/lvolZ,
where FS = "Size" from "vgdisplay vg0Y" output

d) Grow the filesystem into the free space on lvolZ:
# ext2online /dev/vg0Y/lvolZ

3) You can use mdadm commands to configure RAID-based storage.

Check out the RedHat manual for more information:
http://www.redhat.com/docs/manuals/enterprise/RHEL-4-Manual/s390-multi-install-guide/s1-s390info-raid.html

Regards,
Sergejs

[Morcos]

Hi,
Thanks Sergejs for your answer and I think you deserve more than 10 points.
Still have one thing about mdadm. I created the config file /etc/mdadm.conf and I run the command mdadm -C ...
When I try mdadm /dev/md0 -f /dev/hda1, nothing is changed in /proc/mdstat and I'm not getting hda1[0](F). Also when running mdadm /dev/md0 -r /dev/hda1 I'm getting this message hot remove failed or /dev/hda1: Device or resource busy.

And thx in advance,
Ziad

[Ivan Ferreira]

Can you post the results of:

mdadm --detail /dev/md0

And cat /proc/mdstat

Also, you should know that red hat now provides a way to mirror data using LVM.

[Morcos]

Hi,

the result of mdadm --detail /dev/md0 is:
...
Raid level: raid0
Raid devices:2
total devices:2
...

State: clean
Active devices:2
working Devices:2
Failed devices:0
Spare devices:0
chunk size: 64K

Number Major Minor RaidDevice State
0 3 6 0 active sync /dev/hda6

1 3 7 1 active sync /dev/hda7


cat /proc/mdstat
personalities: [raid0]
md0 : active raid0 hda7[1] hda6[0]

unused devices:

For the lvm raid isn't the same? or how to proceed.

Thx in advance.
Ziad

[Ivan Ferreira]

I think that the mdadm -f refuses to work because you have a RAID 0 without fault tolerance.

[Morcos]

Hi,
Thanks lvan for your reply, last time you mentioned doing raid for lvm, isn't the same using mdadm or how to do it on lvm.

Best regards,
Ziad

[Stuart Browne]

LVM is usually on-top-of RAID, for reliablity.

[Ivan Ferreira]

LVM is just another way to mirror the data, you can use without md devices. LVM is used by AIX and HP-UX to mirror the data. But, you should only test with it, it's the very first release and I think that should not be used yet in a production environment.

I though that you where in the process of testing and practicing.

[Morcos]

Hello guys,
One more question, I was configuring a pop3 server using dovecot. In /etc/dovecot.conf I change it to : protocols = pop3 pop3s and I restart the dovecot service.
I test the pop3 by: telnet localhost 110 and it's ok.
Then I tried : telnet localhost 995 to test the pop3s but the connection failed.
So where could be the problem?

Kind regards,
Ziad

[Steven E. Protter]

Shalom again.

port 995 is may be blocked by firewalls.

To use this with popmail you may need to install a ssl certificate on the server.

http://www.zend.com/tips/tips.php?id=152&single=1

http://confluence.atlassian.com/display/DOC/Configure+SSL+access+for+Confluence+Standalone

These docs might help. I have a script that does most of the work, but following the document is the best way to go.

The raid procedure on redhat is the same for lvm or non-lvm. There is no lvextend -m 1 like hp-ux because thats actually an add in feature that comes from mirror/ux

SEP