LS441D running in degraded mode

[alansamsa]

I have a LS441D NAS which is operating in degraded mode (code I12).
Disk 4 is shown as 'failed'.
Can I keep operating in this mode (seems to operate fine) or do I need to change the disk ASAP?
If the latter, what is the best procedure?
Thanks

[Texturtle]

Bear in mind that those drives are likely all about the same age. If a second drive fails you will lose all data on the unit. Do you have a backup of all the data? You should replace the drive immediately. Here's the procedure: https://www.buffalo.jp/s3/guide/ls/400/99/en/pc_index.html?Chapter4#h3anc8

[alansamsa]

Thanks for the advice, will try that !

[alansamsa]

What disks are suitable to install / replace into the LS441D?
Can I just get any hard disk of same size or does it need to be specific for the NAS I have?
Thanks

[alansamsa]

Hi, if I do not replace the failed drive (one of four) and then keep the NAS as three drives, can I redo the array as three drives (with a single HD port empty)? OR does the NAS redo the array with three drives only?

[Texturtle]

You can't do that and retain the data currently stored on the array.