I've recently been having a bit of fun(?) solving a problem where one of our ZFS clusters was allowed to fill all the space allocated to it.
Along the way I (re)discovered in "Distributed File Service zSeries File System Administration" (SC24-5989): <quote> ...Assuming that each volume is a 3390 with 3338 cylinders (with 3336 cylinders free), that there are 15 tracks per cylinder and that you can get 6 8K blocks per track (15 x 6 = 90 8K blocks per cylinder), you should get 90 x 3336 = 300240 8K blocks per volume and 10 x 300240 = 3002400 8K blocks in the aggregate... </quote> My question is: "Is there any way to change that 8K block size up to something larger?" When defining the linear cluster in the first place, can I, for instance, specify a CISIZE of, say, 27648 bytes - without being overridden by some in-built limitation? The reason I ask is that with 8K blocks, you - as the manual states - get 6 blocks per track. With a track size of 56664 bytes, this means that you use 49152 bytes on each track. In other words, 13% of the allocated disk space is quite simply being thrown away. Yes, yes, yes - I _know_ that "disk space is cheap" these days but 13% waste still strikes me as a bit much to have to swallow. If I could bring it down to less than 5% or so, I'd feel a lot happier. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
