I have just found very interesting post on reddit about 8GB FC vs 10GB iSCSI. Continue reading
8GB FC or 10GB iSCSI?
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Author Archives: iwik
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. Continue reading
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. Continue reading
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 mouting this export on client:
Stale NFS file handle
This error is strange and confusing. Workaround is to specify fsid in /etc/exports for this filesystem.
For more information check this nice blog article https://hpc.uni.lu/blog/2014/xfs-and-inode64/
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. Continue reading
VMware backup script
I have been searching for simple and easy script to backup selected virtual machines running on esxi server, which will:
- run on linux – do not require windows machine; can’t use PowerCLI
- do not require direct access to esxi host using ssh (as other backups scripts like ghettoVCB.sh do) and will use API
- support multiple esxi hosts managed by vcenter
- have clear code – that means no perl hell (including big vsphere perl sdk)
- have short code
- can be put into cron
I was unable to find any to comply my requirements. I’m learning python, so I searched for some python vsphere libs and found psphere. Then backup.py has born.
Country CIDR IP ranges
In my previous post I have showed how to easily generate IP range assigned to some country. I have modified this previous script to generate IP blocks for all countries and put it online for free download and usage.
Generating country IP ranges lists
There are many sites providing country blocklists, for example http://www.ip2location.com/free/visitor-blocker or https://www.countryipblocks.net/. When you want periodicaly update such list, you have problem. You need pay for that service for automated access, actual data or “hack” access to that service (abuse their free access conditions)…
Debian iso images with firmware included
Are you getting angry when installing Debian and your network cards (eg. bnx2) are not working because of missing non-free firmware policy? Solution is simple – just use for installation unofficial Debian iso images with firmware. Continue reading
Commercial DNS (IP) blacklists
Everyone know common dns blacklists used for rejecting emails. To check, if ip address is blacklisted on some blacklist, it is common to use service like mxtoobox.com. But what check next, if mxtoolbox shows ip is not blacklisted and email or connections are still rejected (sometimes without any reason) by some servers?
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