Prakash Surya

Thanks for opening the issue! Here's a concrete example from sdb, where we thought the lack of a drgn-specific exception might hide non-drgn `ValueError` execeptions; here's a [link](https://github.com/delphix/sdb/blob/master/sdb/commands/stacks.py#L230) .. and...

I'm not an expert in this area of the code, but I think that swap on ZVOL is inherently unreliable due to writes to the swap ZVOL having to go...

@behlendorf that's unfortunate; given there's no good entry point to do the preallocation, your two suggestions seem reasonable at first glance. Using a new `ioctl` (or create-time property) to preallocate...

@didrocks I gave some information on a possible approach to address this long term, in my comment above. At this point, I think it's accepted that using a ZVOL for...

> I'd personally really prefer to see a design where at least checksums can be maintained functional I think we'd all prefer this, but I don't think it's currently possible...

@ryao In what you're proposing, where we lean heavily on the ZIL to do the writes, we'll still need to do on-disk allocations "on demand" as we write out data...

``` sdb> echo 0xffff98c0bdc630c0 | cast zio_t* | member io_bp | blkptr DVA[0]= [L0 ZIL intent log] zilog2 uncompressed unencrypted LE contiguous unique single 20000L/20000P birth=102888885L/102888885P fill=0 cksum=31f21b5d88444753:eb8c9d829c60c5f6:17bb3:33e ``` I...

http://ops.jenkins.delphix.com/job/devops-gate/job/master/job/appliance-build/job/master/job/post-push/1522/

``` Traceback (most recent call last): File "/usr/lib/python3/dist-packages/sdb/commands/threads.py", line 31, in getcmdline return cmdline(obj) File "/usr/lib/python3/dist-packages/drgn/helpers/linux/mm.py", line 253, in cmdline return access_remote_vm(mm, arg_start, arg_end - arg_start).split(b"\0")[:-1] File "/usr/lib/python3/dist-packages/drgn/helpers/linux/mm.py", line 233,...

I believe we already use readline; and tab completion (perhaps the others, too) should currently work. I think this issue is more about adding the ability to use vi key-bindings...