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September 4, 2012

Replacing a defective drive from a raid 1

Filed under: Linux — Tags: , , , , , , , , — admin @ 10:51 am

Well yesterday I receive daily e-mail and saw that my raid is failing .

cat /proc/mdstat
Personalities : [raid1] [raid0] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sdb1[1] sda1[0]
2102464 blocks [2/2] [UU]

md1 : active raid1 sdb2[1] sda2[0]
264960 blocks [2/2] [UU]

md2 : active raid1 sdb3[2](F) sda3[0]
1462766336 blocks [2/1] [U_]

So that mean that sdb3 is marked as failed drive and U_ mean that raid is degraded.
Well from this point I remove the sdb1 and sdb2 from raid but before I mark them as failed

mdadm --manage /dev/md1 --fail /dev/sdb2
mdadm --manage /dev/md0 --fail /dev/sdb1

mdadm /dev/md0 -r /dev/sdb1
mdadm /dev/md1 -r /dev/sdb2
mdadm /dev/md2 -r /dev/sdb3

After replacement of hard drive I have to recreate the same partition on new sdb and add it to raid.

sfdisk -d /dev/sda | sfdisk /dev/sdb
mdadm /dev/md0 -a /dev/sdb1
mdadm /dev/md1 -a /dev/sdb2
mdadm /dev/md2 -a /dev/sdb3

Now watch how your raid is recovering
watch cat /proc/mdstat
Every 2.0s: cat /proc/mdstat Tue Sep 4 09:52:52 2012

Personalities : [raid1] [raid0] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sdb1[1] sda1[0]
2102464 blocks [2/2] [UU]

md1 : active raid1 sdb2[1] sda2[0]
264960 blocks [2/2] [UU]

md2 : active raid1 sdb3[2] sda3[0]
1462766336 blocks [2/1] [U_]
[===>.................] recovery = 16.0% (234480192/1462766336) finish=412.8min speed=49580K/sec

unused devices:

However the speed my by low so how to increase that speed ?

cat /proc/sys/dev/raid/speed_limit_max
200000
cat /proc/sys/dev/raid/speed_limit_min
1000

Now I increase the min limit to 50000
echo 50000 >/proc/sys/dev/raid/speed_limit_min

Now if you watch cat /proc/mdstat again you will see that your speed is improved and your time get low.

August 13, 2012

Failed to download pecl/ssh2 within preferred state “stable”, latest release is version 0.11.3

Filed under: Linux — Tags: , , , , — admin @ 11:49 am

Today I was trying to upgrade a php on centos 5.4 from php 5.2 to php 5.3
The upgrade was run using

rpm -Uvh http://repo.webtatic.com/yum/centos/5/latest.rpm
yum --enablerepo=webtatic update php

Well everythins was ok, however after upgrade I see that if I run php -v i got some errors, memcache and ssh2 was installed using pecl and they should be reinstalled.
Well the pecl install memcache work well however
pecl install ssh2
return this error
Failed to download pecl/ssh2 within preferred state “stable”, latest release is version 0.11.3,

Well I did manage to install it by using
pecl install “channel://pecl.php.net/ssh2-0.11.3”

Regards

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