LS-WXL/R1 1 drive replacement

[jeanclodo]

Hello
I'm new in this forum.
I Have a RAID 1 LS-WXL and one of the hard disk must n$be replaced. Message is I12: La matrice RAID fonctionne en mode dégradé.
Hard drives are WD10EADS-22M2B0 Western digital Caviar.
Can I replace the defective hard drive by a Western digital Red series WD10EFRX 64 MB Cache ?
Is it better to replace both drives ? They are nearly 7 years old.
One more problem: When I open the Link Station, The drives are numbered 1 and 2 from left to right.
But on the web admin/system/storage/disks, Disk 1 has Error status, Disk 2 has a status of Array 1.
This makes me a little confuse. I don't know if I have to replace drive numbered 1 on the link Station or drive numbered 2.
I hope my explanation is clear enough.....
Thank you in advance four your advice.
Bets regards

[Texturtle]

Disk 1 should be replaced. Any SATA drive of the same size or lager should work fine.

[jeanclodo]

Thanks for your reply
I changed drive 1 and it Works fine now

Best regards