Quantcast
Channel: vBlog by Viktor Balogh » Storage
Browsing all 12 articles
Browse latest View live

Calculating the HW path for a LUN

Ensure that the LUN number is represented in decimal; an HP XP disk array uses hexadecimal LUN numbers while an HP VA disk array uses decimal LUN numbers. The Virtual SCSI Bus starts at address 0. If...

View Article



Displaying the FC load per card

Here is a nice script for displaying the load of each FC HBA. It collects the data via sar and then summarize it for every FC HBA. It helps you loadbalance the traffic. #!/bin/sh # # get_fcload – mm...

View Article

Business Copy unleashed

Today we had some trouble with a cluster using Business Copy for backing up the data while the application is running. There is a framework for the automatic conduction of the backup process: it tells...

View Article

Migrating a ServiceGuard cluster to another storage

Here are the steps for offline migrating a Serviceguard cluster to another SAN: create a LUN list:no. of source box no. of source LUN size of source LUN no. of target box no. of target LUN size of...

View Article

Changing the queue_depth parameter

Finally we can get some unusual large LUNs at my customer, but this arose some problems that we didn’t have until now. The read/write performance of a filesystem built from such very large LUNs can...

View Article


HSSM CIM extension install

This guide about installing HP Storage Essentials CIM Extension on HP-UX 11i v1. The following patches are the minimum prerequisites you need to have installed on the system, it may vary depending on...

View Article

Some thoughts about mediainit – low level formatting and why it mustn’t be done

mediainit is neither required nor recommended for most modern disks. In fact, mediainit might damage some (semi-)modern disks. Even the most basic SCSI disks today have a built-in defect management...

View Article

Offline migration – minimizing downtime with rsync

As we all know, downtime is an unavoidable must in some cases. There may be cases when the application need to be migrated to a new system, and it can only be done offline. Even if the downtime can’t...

View Article


Cheatsheet: EMC Powerpath on HP-UX

The latest 11.31 HP-UX version uses native multipathing with the help of the new IO stack. However if you’re on an older version, it was common along many customers to get a Powerpath license from EMC....

View Article


Checking the status of multipathing in 11iv3

A common task in a sysadmin’s life is to assist to the changes which are affecting the SAN network. At smaller organizations it could be that besides the system administrator role you also need to...

View Article

Samsung SSD 840 EVO Performance Restoration on Linux

As you probably all know there was a bug in the firmware of the Samsung 840 EVO SSD drives. After a month of using performance drops heavily while accessing non-changing data. Samsung has finally...

View Article

Importing IOMeter results.csv into Excel

Since I always forget the exact steps here is a list of the steps as a note to self: Rename the results.csv to results.txt Open MS Excel File > Open > Text files type Data type delimited Next...

View Article
Browsing all 12 articles
Browse latest View live




Latest Images