Tag Archives: performance

Checking for Hard drive READ and WRITE Cache (onboard) on Solaris

To check for read and write cache for your hard drives do the following:

Giovanni@server:~# format -e
Searching for disks…done
AVAILABLE DISK SELECTIONS:
0. c8t0d0 <DEFAULT cyl 60797 alt 2 hd 255 sec 252>
/pci@0,0/pci15d9,d380@1f,2/disk@0,0
1. c8t1d0 <ATA-Hitachi HDS72202-A3EA-1.82TB>
/pci@0,0/pci15d9,d380@1f,2/disk@1,0
2. c8t2d0 <ATA-Hitachi HDS72202-A28A-1.82TB>
/pci@0,0/pci15d9,d380@1f,2/disk@2,0
3. c8t3d0 <ATA-Hitachi HDS72202-A3EA-1.82TB>
/pci@0,0/pci15d9,d380@1f,2/disk@3,0
4. c8t4d0 <ATA-Hitachi HDS72202-A3EA-1.82TB>
/pci@0,0/pci15d9,d380@1f,2/disk@4,0
5. c8t5d0 <ATA-Hitachi HDS72202-A3EA-1.82TB>
/pci@0,0/pci15d9,d380@1f,2/disk@5,0
Specify disk (enter its number):

Select a drive, lets pick 5 from the list.

Specify disk (enter its number): 5
selecting c8t5d0
[disk formatted]
/dev/dsk/c8t5d0s0 is part of active ZFS pool gpool. Please see zpool(1M).
FORMAT MENU:
disk       – select a disk
type       – select (define) a disk type
partition  – select (define) a partition table
current    – describe the current disk
format     – format and analyze the disk
fdisk      – run the fdisk program
repair     – repair a defective sector
label      – write label to the disk
analyze    – surface analysis
defect     – defect list management
backup     – search for backup labels
verify     – read and display labels
inquiry    – show vendor, product and revision
scsi       – independent SCSI mode selects
cache      – enable, disable or query SCSI disk cache
volname    – set 8-character volume name
!<cmd>     – execute <cmd>, then return
quit
format>

Now let’s do the checking

Enter “cache” to enter cache menu.

CACHE MENU:
write_cache – display or modify write cache settings
read_cache  – display or modify read cache settings
!<cmd>      – execute <cmd>, then return
quit
cache>

Type: “write_cache” or “read_cache” depending on what you would like to see, lets use write:

cache> write_cache
WRITE_CACHE MENU:
display     – display current setting of write cache
enable      – enable write cache
disable     – disable write cache
!<cmd>      – execute <cmd>, then return
quit
write_cache> display
Write Cache is enabled
write_cache>

Use the same for read_cache and to disable and enable.