The Problem Command 'df' shows statistics but 'ls -ld' fails below: # df ... /dev/mapper/vgapp-appsvol 419221508 15095588 404125920 4% /lapps/app # ls -l /lapps/apps ls: cannot access /lapps/app: Input/output error The Solution Disk failure cases input/output operation stopped, so filesystem is re-mounted as read-only. This is an expected behavior of the kernel to mount a filesystem as read-only to avoid further file system corruption leading to inconsistencies, whenever … [Read more...] about XFS Filesystem Gets Mounted As Readonly (CentOS/RHEL)
How To Create a Local Yum Repository for MySQL Enterprise Packages
1. Obtaining the yum repo tarball 1. Log on to support.oracle.com using your Oracle SSO ID. 2. Click on the "Patches & Updates" tab. 3. Click the "Product or Family (Advanced)" button to search by product. 4. Type "MySQL Server" for the Product. 5. Select the desired version in the "Release" pulldown. 6. Select "Linux x86-64" in the "Platform" pulldown. 7. Select "Description" in the first "and" pulldown under "Platform". 8. Select "contains" in the search type … [Read more...] about How To Create a Local Yum Repository for MySQL Enterprise Packages
How to Check the Size of the Yum Channels in Oracle Linux
Question: How to find out how large a yum channel repository is, to know how much data the channel will sync to a local yum repository? To see the actual size of the repository use either the "yum repolist -v" or "yum repoinfo" command. 1. Example for checking the size of latest OL7 yum channel # yum repoinfo ol7_latest Loaded plugins: langpacks, ulninfo Repo-id : ol7_latest/x86_64 Repo-name : Oracle Linux 7Server Latest (x86_64) Repo-status : enabled Repo-updated : Fri Jan 25 … [Read more...] about How to Check the Size of the Yum Channels in Oracle Linux
Yum Fails with “Error: database disk image is malformed” in /var/log/messages
The Problem Unable to execute any command related to yum and below error messages found in /var/log/messages file. For example: # yum update Loaded plugins: aliases, changelog, downloadonly, kabi, presto, refresh-packagekit, security, tmprepo, verify, versionlock Loading support for kernel ABI Setting up Install Process Ol6_latest | 3.0 kB 00:00 Ol6_latest/primary_db | 78 MB 00:10 [Errno 2] No such file or directory: '/var/cache/yum/x86_64/6Server/Ol6_latest/primary.sqlite.bz2' Loaded … [Read more...] about Yum Fails with “Error: database disk image is malformed” in /var/log/messages
How to use ‘yum’ to connect ULN on CentOS/RHEL/OEL 6
The yum(Yellowdog Updater Modified) service is an automatic update tool to update the system each day. You can use both up2date/yum on Oracle Enterprise Linux/ Oracle Linux. Yum uses a configuration file at /etc/yum.conf. Additional configuration files are also read from the directory set by the reposdir option (default is '/etc/yum.repos.d'). Yum is an automatic updater and package installer/remover for rpm systems. It automatically computes dependencies and figures out what things should occur … [Read more...] about How to use ‘yum’ to connect ULN on CentOS/RHEL/OEL 6
How to Re-Create the Yum Cache and/or Force a Fetch of the Package List of the Enabled Repositories
This post briefly outlines how it possible to re-create the yum cache, or said in another way, force a fetch of the cache data from the enabled yum repositories. The enabled yum repositories are the ones in the following file /etc/yum.conf or in the following folder /etc/yum.repos.d that have their "enabled" setting to "1", e.g. : [public_ol6_latest] name=Oracle Linux $releasever Latest … [Read more...] about How to Re-Create the Yum Cache and/or Force a Fetch of the Package List of the Enabled Repositories
How to Mirror Swap, Boot and Root Partions in CentOS/RHEL 7 Using mdadm Utility
This is required when there is no RAID controller card available for the server and the only solution is software RAID. This post makes changes to partitions, so if there is any existing data on any disks being used for this purpose, it should be backed up prior to creating the RAID array as per standard best practices. 1. In order to mirror the disk, information about partition has to be obtained. This can be done with one of the following commands: # parted /dev/sda u s p # fdisk -l … [Read more...] about How to Mirror Swap, Boot and Root Partions in CentOS/RHEL 7 Using mdadm Utility
MySQL Server Error – “Can’t Create A New Thread (errno 11)”
OS error 11 is "Resource temporarily unavailable". The most common cause of receiving this error when trying to create a new thread is having hit the process's kernel enforced a limit on open file descriptors. The second most common cause is having hit the process's kernel enforced limit on the number of processes/threads. Here are the factors involved: The system-wide limits: sysctl -e fs.file-max && sysctl -e kernel.threads-max The per-process limits (in a *new* shell): ulimit -n, grep … [Read more...] about MySQL Server Error – “Can’t Create A New Thread (errno 11)”
How to use a Wrapper Script to set Custom Per-Process Attributes for MySQL Server
There may be times you need to set custom per-process limits or attributes. It is possible to patch mysqld_safe, but using a wrapper script is easier to implement. In earlier versions, you could use mysqld_safe's mysqld= option to specify the path to your wrapper script, but this feature was removed as of 5.5.52, 5.6.33 and 5.7.15. Currently the simplest solution is to rename the existing mysqld (e.g. to mysqld.bin), and put your script named mysqld in the same directory. Rename the … [Read more...] about How to use a Wrapper Script to set Custom Per-Process Attributes for MySQL Server
SLES 12: Database Startup Error with ORA-27300 ORA-27301 ORA-27303 While Starting using Srvctl
The Problem 12.1 RAC database error while starting via srvctl, alert log showing database startup and further goes down: alert_ORCL2.log inside [oracle base]/diag/rdbms/[db name]/[SID name]/trace: Fri Nov 03 15:06:25 2017 Adjusting the default value of parameter parallel_max_servers from 960 to 486 due to the value of parameter processes (600) Starting ORACLE instance (normal) (OS id: 19684) . . Fri Nov 03 15:10:45 2017 Process startup failed, error stack: Fri Nov 03 15:10:45 … [Read more...] about SLES 12: Database Startup Error with ORA-27300 ORA-27301 ORA-27303 While Starting using Srvctl