As far as routing goes, it is a very bad idea to place multiple network interfaces with IPs of a single network (subnet). The routing table, which decides which interface to route the data through, reads the table line by line, thus – all traffic goes through a single interface of the batch (-> of…
This post is for the users of the great dm-multipath system in Linux, who encounter a major availability problem when attempting a resize of mpath devices (and their partitions), and find themselves scheduling a reboot. This documented is based on a document created by IBM called “Hot Resize Multipath Storage Volume on Linux with SVC”,…
Using iSCSI with dm-multipath is rather common setup. With iSCSI running over Ethernet cables, which are too easy to disconnect (either on purpose or by mistake), being cheap and common technology – multipath becomes a must. If you have multiple network links, this is only expected that you use multipath for your iSCSI configuration. It’s…
dm-multipath is a great tool. Its abilities were proven to me on many occasions, and I’m sure I’m not the only one. NetApp, for example, use it. HP use it as well (a slightly modified version, and still), and it works. A problem I have encountered is as follow – if a single path fails,…
When adding a certain shell to an HP-UX system, for example, /usr/bin/tcsh, each user set to use this shell will not be able to FTP to the machine, until there is entry in /etc/shells. The trick is that even if the file doesn’t exist, you have to create it. By default, HP-UX allows only /sbin/sh…
Not too long ago I have purchased a brand new Hitachi HW100 Workgroup Storage. 14+1 400GB SATA disks, dual-interface, each holding two fiber ports (2Gb/s LC). A nice machine. However, two limitations I have discovered are clouding my day: 1. It supports only Raid0 and Raid5. It will not allow me no-parity Raid, aka, Raid1….
