On Thu, 06 Jan 2011 14:40:23 -0500 (EST), Mark Post wrote: > On 1/6/2011 at 02:22 PM, Stephen Powell <zlinux...@wowway.com> wrote: >> I have recently completed work on enhancements >> to GNU parted to support all combinations of DASD type (CKD and FBA) >> DASD format (cdl, ldl, CMS non-reserved, and CMS reserved) and DASD >> driver (ECKD, FBA, and DIAG) supported by the Linux kernel; > > Where do you live? I'd like to buy you a drink. :)
Where I live is a moot point because I don't drink. But thanks for the offer. Before you get into too much of a celebratory mood, however, perhaps I should offer a bit more explanation as to what this new support does and does not offer. The Linux kernel supports the following combinations: DASD DASD DASD type format driver ---- ------ ------ CKD cdl ECKD CKD ldl ECKD CKD ldl DIAG CKD CMS-NR ECKD CKD CMS-NR DIAG CKD CMS-R ECKD CKD CMS-R DIAG FBA CMS-NR FBA FBA CMS-NR DIAG FBA CMS-R FBA FBA CMS-R DIAG (NR = non-reserved; R = reserved) That's eleven combinations. The DIAG driver is only supported in a virtual machine under z/VM, of course. The current production version of GNU parted supports only the first two combinations. With my enhancements, all eleven combinations are supported. However... Only the first combination supports more than one partition per disk (a maximum of three). And only the first combination supports partition editing (move, resize, etc.). For all the rest, parted simply reports on the pre-existing partition. So if you had visions of re-sizing CMS disks with GNU parted: sorry, I just burst your bubble. By the way, although the Linux kernel supports both non-reserved and reserved CMS minidisks, I recommend reserving them. Once Linux has written to the implicit partition on a CMS non-reserved disk (with mkfs or mkswap) the disk can no longer be accessed by CMS. But CMS reserved minidisks can still be accessed by CMS after Linux has written to the implicit partition with mkfs or mkswap. The implicit partition for a non-reserved minidisk overlays the CMS file system structures (CMS file directory, pointer blocks for allocation map, allocation map, etc.). Therefore, when mkfs or mkswap writes to the partition, these CMS file system structures are destroyed. But the implicit partition for a reserved CMS minidisk consists of the CMS reserved file (except for the last block). Therefore, the CMS file system structures are preserved, and CMS can still access the disk. -- .''`. Stephen Powell : :' : `. `'` `- ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
