Raid 1 with different amounts of Cache on the drives


#1

I sat up a RAID 1 array for a friend of mine using 2 WE10EADS drives and things were fine for about two months.  Then the system would not boot and reported no boot device available.  I checked the RAID controller and it seems to be working.  The RAID utility reports that drive 1 is not a valid raid drive and that drive 2 is ok.  It seems that the first drive has failed and needs to be replaced.  My question is can I replace the WE10EADS with a drive that has a different amount of Cache.  I can find prices on the WE10EARS model but it has 64 meg cache and the WD10EADS has only 32.  I have looked for the WD10EADS but it seems to be out of stock everywhere.


#2

If you are quick you can get them here :

http://www.shg.dk/Harddiske/Western-Digital-1000-GB-2122023.html&ref=edbpriser

Cache size is normally not a problem, but

 advanced drive format EARS series together with EADS, that don’t translate for sector 63 skew is

You can maybe fix the failed WD10EADS by writing zeros to it in the WD dos diagnostics:

http://support.wdc.com/product/download.asp?groupid=608&sid=2&lang=en

And afterwards do a full surface scan/fix in the same program, don’t use windows version that will not fix as many errors as the dos based version.

And don’t forget to set TLER to 7 sec.

But chance is that it will Fail/fall out again so only use them in failsafe RAID modes so you can take drive offline and fix it W/O loosing your data.

Need I mention that a RAID certified drive will be (much) more stable ?

So if you would avoid problems better replace with http://www.wdc.com/en/products/Products.asp?DriveID=503

that is known to be stable (if you still can buy them somewhere)

Don’t know if the new RE4 is ok but stay away from WD2002FYPS this drive will only give you problems in my experience. (yes I own several WD10EADS, WD1002FBYS and a single WD2002FYPS)