On 07/01/2016 23:34, mchristi@xxxxxxxxxx wrote: > From: Mike Christie <mchristi@xxxxxxxxxx> > > Another iscsi target that cannot handle large IOs, > but does not tell us a limit. > > The Synology iSCSI targets report: > > Block limits VPD page (SBC): > Write same no zero (WSNZ): 0 > Maximum compare and write length: 0 blocks > Optimal transfer length granularity: 0 blocks > Maximum transfer length: 0 blocks > Optimal transfer length: 0 blocks > Maximum prefetch length: 0 blocks > Maximum unmap LBA count: 0 > Maximum unmap block descriptor count: 0 > Optimal unmap granularity: 0 > Unmap granularity alignment valid: 0 > Unmap granularity alignment: 0 > Maximum write same length: 0x0 blocks > > and the size of the command it can handle seems to depend on how much > memory it can allocate at the time. This results in IO errors when > handling large IOs. This patch just has us use the old 1024 default > sectors for this target by adding it to the scsi blacklist. We do > not have good contacs with this vendors, so I have not been able to > try and fix on their side. Synology is just (an old fork of?) LIO. IIRC I saw similar problems a couple years ago with LIO because iscsit_map_iovec maps everything a page at a time and produced too large an iovec for the underlying storage. I'm afraid you're going to get this for pretty much every user of LIO. Paolo -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
