Questo sito utilizza cookie di profilazione (propri e di terze parti) per ottimizzare la tua esperienza online e per inviarti pubblicità in linea con le tue preferenze. Continuando a utilizzare questo sito senza modificare le tue preferenze acconsenti all’uso dei cookie. Se vuoi saperne di più o negare il consenso a tutti o ad alcuni cookie clicca qui>
The website that you are visiting also provides Arabian language. Do you wish to switch language version?
يوفر موقع الويب الذي تزوره المحتوى باللغة العربية أيضًا. هل ترغب في تبديل إصدار اللغة؟
The website that you are visiting also provides Russia language Do you wish to switch language version?
Данный сайт есть в английской версии. Желаете ли Вы перейти на английскую версию?
Product and version information:
The storage array was connected to the application server through iSCSI connections. The Asianux host used IOmeter to perform read/write testing on the LUN mapped from the storage array. During the read/write operations, an iSCSI link-down occurred (caused by a cable removal or unexpected power-off). The host CPU utilization was close to 100% and the host was not responding even to SSH or KVM login attempts.
Dynamo on Linux has an infinite retry mechanism. When a slave block device returned an i/o error to upper-layer applications, Dynamo retried this failed I/O immediately, but the iSCSI driver returned this retry I/O as an error. The above situation was a logical infinite loop. This infinite loop resulted in a CPU utilization of close to 100% as shown in Figure1.
Figure 1 CPU utilization
When the CPU utilization was close to 100%, the host may not respond to any external events.
We ran the same test on a Red Hat5.4 host, and the same symptoms occurred