RAID 1 | Changing HDs

["Stefanie Leisestreichler (Febas)" <stefanie.leisestreichler@peter-speer.de>]

Hi.
I have the system layout shown below.

To avoid data loss, I want to change HDs which have about 46508 hours of 
up time.

I thought, instead of degrading, formatting, rebuilding and so on, I could
- shutdown the computer
- take i.e. /dev/sda and do
- dd bs=98304 conv=sync,noerror if=/dev/sda of=/dev/sdX (X standig for 
device name of new disk)

Is it save to do it this way, presuming the array is in AA-State?

Thanks,
Steffi

/dev/sda1:
           Magic : a92b4efc
         Version : 1.2
     Feature Map : 0x0
      Array UUID : 68c0c9ad:82ede879:2110f427:9f31c140
            Name : speernix15:0  (local to host speernix15)
   Creation Time : Sun Nov 30 19:15:35 2014
      Raid Level : raid1
    Raid Devices : 2

  Avail Dev Size : 1953260976 (931.39 GiB 1000.07 GB)
      Array Size : 976629568 (931.39 GiB 1000.07 GB)
   Used Dev Size : 1953259136 (931.39 GiB 1000.07 GB)
     Data Offset : 262144 sectors
    Super Offset : 8 sectors
    Unused Space : before=261864 sectors, after=1840 sectors
           State : active
     Device UUID : 5871292c:7fcfbd82:b0a28f1b:df7774f9

     Update Time : Thu Aug 28 01:00:03 2025
   Bad Block Log : 512 entries available at offset 264 sectors
        Checksum : b198f5d1 - correct
          Events : 38185

    Device Role : Active device 0
    Array State : AA ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdb1:
           Magic : a92b4efc
         Version : 1.2
     Feature Map : 0x0
      Array UUID : 68c0c9ad:82ede879:2110f427:9f31c140
            Name : speernix15:0  (local to host speernix15)
   Creation Time : Sun Nov 30 19:15:35 2014
      Raid Level : raid1
    Raid Devices : 2

  Avail Dev Size : 1953260976 (931.39 GiB 1000.07 GB)
      Array Size : 976629568 (931.39 GiB 1000.07 GB)
   Used Dev Size : 1953259136 (931.39 GiB 1000.07 GB)
     Data Offset : 262144 sectors
    Super Offset : 8 sectors
    Unused Space : before=261864 sectors, after=1840 sectors
           State : active
     Device UUID : 4bbfbe7a:457829a5:dd9d2e3c:15818bca

     Update Time : Thu Aug 28 01:00:03 2025
   Bad Block Log : 512 entries available at offset 264 sectors
        Checksum : 144ff0ef - correct
          Events : 38185