Slightly related, well it is multi-channel {:-), but does anyone have any experience with using a DEC Storage works array under dual linux hosts?[1]1) can it be done?
Yes. It's a filesystem issue, not specifically a host issue, although you do need to make sure that your storageworks array is the type that will map the same filesystems to multiple hosts (early models won't do that).
2) which distros?[2]
RHEL 3 with OCFS. RHEL 4 with OCFS2 should work as should GFS (I've never tried it with GFS). I've seen people fail in an extremely spectacular manner trying it with ext3. However OCFS is the only filesystem that I've gotten it to work on personally.
3) other stuff?
You may be able to get GFS for a really recent Debian, 2.6.9 kernel or thereabouts. You will probably need OCFS if you want this to work on earlier / 2.4 kernels. OCFS can't be used to store files -- only Oracle databases. You may have some joy with OCFS2 instead, not sure what kernels that's supported under. I suspect that OCFS2 is probably more stable than GFS, but GFS has some performance advantages. Oracle would like you to use OCFS2, Red Hat would like you to use GFS. Choose your poison. Neither will support you running on Debian, so you may need to build from source and google a lot. YMMV. It was really unstable, and crashed a lot. I suspect that was the hardware. The ventilation needed to be really good or it spat disks out at an alarming rate. The need to rebuild an entire RAID array to expand the size of the storage was a complete pain, and it wasn't the fastest box to rebuild arrays on. Make sure you know which direction your SCSI buses and SCSI IDs are numbered in the chassis -- some storageworks models cable the busses going down and the IDs left to right, some do it the other way. Getting multiple disks in the same array spanning multiple busses within the storageworks chassis can improve your performance a lot, so sometimes you need to fill the arrays top to bottom and sometimes you need to fill them left to right. Generally the storageworks units I played with left a lot to be desired in comparison with the EMC gear. I wouldn't buy one or recommend one to a client, however if one's fallen into your lap it may be a fun toy, and better than a stack of yellow sticky notes from a storage point of view. -- Del -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
