To make the Web cache more secure, you should use a hard disk volume formatted with NT file system (NTFS). 300MHz of higher Pentium II compatible CPU. 256 MB of RAM. 20MB of hard disk space – excludes space for the ISA Server cache. To improve hard disk performance and redundancy, consider using Redundant Array of Independent Disks (RAID) arrays. Because server disks need to be fast and reliable, grouping drives so that they perform together to provide speed and fault tolerance is a solution that can be implemented to achieve this. Use RAID level 1 to mirror the operating system. Two disks partake in a mirrored volume. This configuration is also known as a mirror set. With mirroring, two copies of all data are written to separate volumes on two different disks. In the case where one disk fails, the remaining disk in the mirror volume set has an identical copy of the data. RAID 1 is frequently used to protect the drive where the operating system is situated. It is a good initiative to mirror the boot and system volume to ensure that you can boot the server in the event of a single drive failure. You only need two physical disks to create a mirror volume set. It is also possible to mirror an existing simple volume set, thereby making it fault tolerant.
You can improve fault tolerance by separating the ISA Server Web cache and the ISA Server logs.
Consider using Web cache space on multiple drives to provide fault tolerance. This would mean that should one drives crash, the failure is isolated to the cached data on that specific drive only. The other drives would still be able to operate as usual.
Use a RAID level 5 array for logs. RAID 5 uses disk striping with parity. Fault tolerance ensures that a single drive failure does not result in the whole set being down. To enable fault tolerance, RAID 5 writes parity information with the blocks of data. Whenever data is written to RAID-5 volumes, it is written across all the striped disks in the RAID 5 volume, and parity information for the data is also written to disk. Parity information is written to a separate disk from that disk holding the matching data. A disk in the RAID-5 volume can hold a portion of the data, or the parity information which would be used to reconstruct the contents of a lost disk. The original data and parity information is not stored on the identical disk. This parity information is then used to recover the data when a disk in the striped set fails.