iwik
Using mod_geoip in .htaccess
There has been some comments in my old posts trying to use generated country lists in Apache .htaccess. This approach is wrong, and I will show you much better way how to block or allow specific country.
Generating country IP ranges lists #2
My original article about this topic is more that year old and was using Regional Internet Registries (RIRs) list as source and was in python. This post will describe other simple solution how to generate some country IP ranges list.
Performance impact when using VMware snapshots
Using vmware and snapshots? You probably know about vmware best practices about snapshots, which includes
- The maximum supported amount of snapshots in a chain is 32. However, VMware recommends that you use only 2-3 snapshots in a chain.
- Use no single snapshot for more than 24-72 hours. Snapshots should not be maintained over long periods of time for application or Virtual Machine version control purposes.
- An excessive number of delta files in a chain (caused by an excessive number of snapshots) or large delta files may cause decreased virtual machine and host performance.
- Be especially diligent with snapshot use on high-transaction virtual machines such as email and database servers
But what is real performance inpact of snapshot?
Dropbox on network drive
Have you tried to place your Dropbox folder on network (NAS) drive? Dropbox don’t allow it directly, but there is hack…
Read More »Dropbox on network drive
8GB FC or 10GB iSCSI?
I have just found very interesting post on reddit about 8GB FC vs 10GB iSCSI. Read More »8GB FC or 10GB iSCSI?
Protecting WordPress with mod-security
This my blog and also other hosted websites running WordPress are target of bots trying passwords to wordpress admin and posting spam comments. I was unable to found simple plugin for comments dns blacklist, so I focused to mod-security. Read More »Protecting WordPress with mod-security
Replacing vCenter Server Appliance SSL certificates
vCenter and SSL is always a pain. Simple thing as replacing default self-signed SSL certificates with CA signed has in official VMWare KB2057223 40(!!!) steps. Read More »Replacing vCenter Server Appliance SSL certificates
Big XFS filesystem NFS export mount fails with stale nfs handle
If you have big XFS filesystem (with lot of files) and you use inode64 mount option, exporting this file system using NFS may fail when… Read More »Big XFS filesystem NFS export mount fails with stale nfs handle
Snapshoting virtual machine running mysql database
Backup in virtualized enviroment is mostly based on snapshoting entire virtual machine and saving this state to backup repository. This snapshot does not include memory of virtual machine. When you restore virtual machine from this snapshot filesystem is in unclean state, but journal filesystem can handle this. From mysql point of view server crash happended and database can be corrupted and unrecoverable, depending on what queries where running during snapshot. This unpredicted and unconsistent state you don’t want to have as a backup of your data. Read More »Snapshoting virtual machine running mysql database